ECRIS2012 - List of Keywords (ion-source)

Paper	Title	Other Keywords	Page
TUXO01	Coupling Microwave Power into ECR Ion Source Plasmas at Frequencies above 20 GHz	plasma, ECR, ion, coupling	1
	C.M. Lyneis, J.Y. Benitez, M.M. Strohmeier, D.S. Todd LBNL, Berkeley, California, USA
	Electron Cyclotron Resonance (ECR) ion sources have been built to operate at frequencies from 5 GHz to 28 GHz and typically use a plasma chamber that serves as a multi-mode cavity. For small sources operating at 6 to 14 GHz cavity mode-like behavior has been reported. In these cavities the vacuum mode density is low enough that it may be that the RF power distribution can be understood in terms of excitation of a few modes. The large superconducting ECR ion sources, such as VENUS, operating at higher frequencies have a much greater mode density and very strong damping from plasma microwave adsorption. In this type of source, how the RF is launched into the plasma chamber will strongly affect the microwave coupling and the chamber walls will be less important. The VENUS source uses round over-moded TE01 mode waveguide to couple to the plasma, while most modern fusion devices use quasi-gaussian HE11 waves for injection into plasmas. In this paper we will describe the potential advantages of applying this technology to superconducting ECR ion sources as well as designs for doing so with VENUS.
	Slides TUXO01 [18.302 MB]

TUXO02	An Experimental Study of ECRIS Plasma Stability and Oscillation of Beam Current	ECR, plasma, ion, ECRIS	5
	O.A. Tarvainen, T. Kalvas, H. A. Koivisto, J.P.O. Komppula, V. Toivanen JYFL, Jyväskylä, Finland C.M. Lyneis, M.M. Strohmeier LBNL, Berkeley, California, USA
	The stability of oxygen ion beams extracted from ECR ion sources has been studied with the superconducting ion source VENUS at LBNL and with the A-ECR type 14 GHz ECRIS at JYFL. Discrete Fourier transform has been used for characterizing beam current oscillations in kHz range exhibited by both ion sources. The effect of source parameters on the frequency and amplitude of the oscillations is discussed. It was found that double frequency heating affects the oscillation frequency, biased disc can be used to mitigate the amplitude of beam current fluctuations, increasing B-minimum results to pronounced instabilities and operating the ion source with significantly higher mirror ratio than suggested by ECRIS scaling laws yields the most stable ion beams. It is argued that the observed beam current fluctuations are correlated with plasma instabilities. A 'roadmap' for identifying the plasma instability mechanisms responsible for beam current fluctuations is presented.
	Slides TUXO02 [2.195 MB]

TUXO03	Two-frequency Heating Technique for Stable ECR Plasma	plasma, ion, ECR, ECRIS	10
	A. Kitagawa, M. Muramatsu NIRS, Chiba-shi, Japan S. Biri, R. Rácz ATOMKI, Debrecen, Hungary T.F. Fujita National Institute of Radiological Sciences, Chiba, Japan Y. Kato Osaka University, Graduate School of Engineering, Osaka, Japan N. Sasaki, W. Takasugi AEC, Chiba, Japan
	As a method to improve highly charged ion production, a technique to feed multiple microwaves with different frequencies is well-known. However the reason is not made sufficiently clear. Our group studied with two frequencies close together with a power of 600 W over by 18 GHz NIRS-HEC ECR ion source installed in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). As a result, it was revealed that the improvement of output beam current depends on the total power. In this case it seems that the two-frequency heating technique carries the advantage that the plasma instability at high microwave power is relieved. The effectiveness of an additional microwave depends on its frequency. It is necessary to optimize an additional frequency precisely; several tens MHz step against 18 GHz. The optimized frequency is directly influenced by the magnetic configuration. The necessary requirements for an additional microwave and the procedure of optimization in order to obtain a large advantage will be discussed.
	Slides TUXO03 [1.590 MB]

TUYO02	Control of the Plasma Transversal Losses, Caused by MHD Instabilities, in Open Mirror Magnetic Trap of the ECRIS: Recent Experiments on SMIS 37 Setup	plasma, ion, ECR, electron	18
	V. Sidorov, I. Izotov, S. Razin, V. Skalyga, V. Zorin IAP/RAS, Nizhny Novgorod, Russia
	Funding: This work was partially performed in the framework of the Federal Targeted Program 'Scientific and Educational Personnel of the Innovative Russia' for 2009-2013 This work is a continuation of the experiments described in [1, 2] and aimed at the investigation of the new conceptions of MHD stabilization of plasma in open axisymmetric traps, specifically, it is aimed at the investigation of the shear flow influence on the transport control in open mirror traps. As in previous experiments, shear flow was created by limiter-electrode with bias potential according to the vacuum chamber. Plasma density structure in radial and azimuthal directions was studied. Mode structure of the perturbations was investigated. Substantial sharp shift of the plasma density maximum to the system axis with bias potential growth was demonstrated. It was shown, that the value of the bias potential that corresponds to the plasma density profile shift grows with the magnetic field growth that can be interpreted as the electron temperature growth. Some theoretical estimations of the influence of the transversal losses decrease on plasma parameters were made. [1] A.Sidorov, P.Bagryansky, A.Beklemishev et al. Trans. Fusion Sci. and Technology, 59, 112, (2011). [2] I.Izotov, S.Razin, A.Sidorov et al. Rev. Sci. Instrum., 83, 02A318 (2012).
	Slides TUYO02 [1.542 MB]

TUZO02	Detailed Investigation of the 4D Phase-Space of an Ion Beam	ion, emittance, dipole, cyclotron	30
	H.R. Kremers, J.P.M. Beijers, S. Brandenburg, V. Mironov, S. Saminathan KVI, Groningen, The Netherlands
	A second order transfer matrix is calculated, which is used in the calculation of a 4D phase-space distribution of a 24.6 keV He¹⁺ beam. The calculated distribution matches a 4D phase-space distribution measured with the KVI pepper pot emittance meter. The pepper pot emittance meter is installed in the image plane of a dipole magnet acting as a charge-state analyser directly downstream the KVI AECR ion source. From the second order transfer matrix simple analytical equations are derived by retaining the terms for angular coefficients. These simple equations describe the main features of the phase-space correlations in the image plane. The equations show also that the subset of the 4D phase-space distribution, selected by one pepper pot aperture, results in multiple beam-lets. Due to this successful matrix modelling we conclude that the 4D phase-space distribution measured is fully determined by the ionoptical properties of the magnet.
	Slides TUZO02 [6.348 MB]

TUPP01	Quantitative Determination of ¹⁴⁶Sm/¹⁴⁷Sm Ratios by Accelerator Mass Spectrometry with an ECR Ion Source and Linear Acceleration for ¹⁴⁶Sm Half-Life Measurement	ion, ECR, detector, target	43
	N. Kinoshita UTTAC, Tsukuba, Ibaraki, Japan P. Collon, Y. Kashiv, D. Robertson, C.J. Schmitt, X.D. Tang University of Notre Dame, Indiana, USA C. Deibel MSU, East Lansing, Michigan, USA C. Deibel, B. DiGiovine, J.P. Greene, D. Henderson, C.L. Jiang, S.T. Marley, R.C. Pardo, E. Rehm, R.H. Scott, R.C. Vondrasek ANL, Argonne, USA T. Nakanishi, A. Yokoyama Kanazawa University, Kanazawa, Japan M. Paul The Hebrew University of Jerusalem, The Racah Institute of Physics, Jerusalem, Israel
	Funding: Supported by U.S. DOE, Office of Nuclear Physics, contract No. DE-AC02-06CH11357, NSF JINA Grant Nr. PHY0822648 and Science Research Prog. of Japan Society for the Promotion of Science (20740161) The alpha-decaying ¹⁴⁶Sm nuclide is used for chronology of the Solar System and silicate mantle differentiation in planets. We performed a new determination of 146Sm half-life by measuring ¹⁴⁶Sm/¹⁴⁷Sm alpha activity and atom ratios in ¹⁴⁷Sm activated via (g,n), (n,2n) and (p,2n) reactions and obtained a value (68 Myr), smaller than that adopted so far (103 Myr), with important geochemical implications. The experiment required determination of ¹⁴⁶Sm/¹⁴⁷Sm ratios by high-energy (6 MeV/u) accelerator mass spectrometry to discriminate ¹⁴⁶Sm from isobaric ¹⁴⁶Nd contaminant. Activated Sm targets were dissolved, chemically purified and reconverted to metallic Sm. Sputter cathodes, made by pressing the Sm metal into high-purity Al holders, were used to feed the Argonne ECR ion source. ¹⁴⁶Sm²²⁺, ¹⁴⁷Sm²²⁺ ions were alternately injected and accelerated with the ATLAS linac by proper scaling of ion source and accelerator components. A tightly-fitted quartz cylindrical liner was inserted in the ECR plasma chamber to reduce contamination from the walls. ¹⁴⁶Sm ions were eventually counted in a gas-filled magnet and ¹⁴⁷Sm ions either measured as charge current or counted after proper attenuation. N. Kinoshita et al., Science 334, 1614 (2012)

TUPP03	Integration of a Third Ion Source for Heavy Ion Radiotherapy at HIT	ion, operation, extraction, emittance	46
	T.W. Winkelmann, A.B. Büchel, R. Cee, A. Gaffron, Th. Haberer, J.M. Mosthaf, B. Naas, A. Peters, J. Schreiner HIT, Heidelberg, Germany
	HIT is the first European hospital based facility for scanned proton and heavy ion radiotherapy. In 2009 the clinical operation started, since then more than 800 patients were treated in the facility. In a 24/7 operation scheme two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce protons and carbon ions. In the near future a helium beam for regular patient treatment is requested. The modification of the low energy beam transport line (LEBT) for the integration of a third ion source into the production facility was done in winter 2011. For beam quality improvement with a smaller emittance at the same current we designed and tested a new extraction system at the testbench and equipped the source for protons and helium with this optimized system. This paper will present results of the LEBT modification and gives an outlook to further enhancements at the HIT ion source testbench.

TUPP04	Design of a Compact ECR Ion Source for Various Ion Production	ion, extraction, ECR, plasma	49
	M. Muramatsu, S. Hojo, Y. Iwata, K. Katagiri, A. Kitagawa, Y. Sakamoto, S. Sato NIRS, Chiba-shi, Japan A.G. Drentje KVI, Groningen, The Netherlands T.F. Fujita National Institute of Radiological Sciences, Chiba, Japan
	Compact ECR ion source with all permanent magnets, so called Kei2, was developed for high energy carbon ion therapy facility at National Institute of Radiological Sciences. Kei2 source was design for production of only carbon ion for medical treatment. A copy of Kei2, so called KeiGM is used for Gunma University. Kei series are optimized for carbon ion production. In order to produce various ion beams for research, we design a new compact ECR ion source, so called Kei3. Kei3 is designed based on previous Kei series. In addition, there are three important points: 1) Movable beam extraction system for various extraction current densities, 2) An evaporator and MIVOC method for production of ions from solid materials and metal, and 3) Biased disk method and double frequency heating method for heavier ions. Same permanent magnets and microwave system will be used for easy maintenance and the cost effectiveness. Design of the Kei3 source will be described in this paper.

TUPP17	Installation and Operation of a 28 GHz Gyrotron for the RIKEN Superconducting ECR Ion Source	cathode, ion, detector, power-supply	71
	J. Ohnishi, Y. Higurashi, T. Nakagawa RIKEN Nishina Center, Wako, Japan
	The RIKEN 28-GHz ECRIS uses a gyrotron microwave source fabricated by Mitsubishi Electric Corporation. The maximum output power is 10 kW. The gyrotron produces TE02-mode microwaves, which are converted into the TE01 mode by a mode converter. In the first test on the gyrotron performed using a dummy load, we observed the 50-300 Hz ripples of ~500 W in the output power of 1-7 kW, and it was difficult to make a stable operation in the low-power. These ripples were reduced to one-tenth by stabilizing the cathode voltage and then the gyrotron could produce microwaves from < 0.5 kW stably. The operation of the ion source with the 28 GHz gyrotron was started in 2011 and the ion source supplied U and Xe beams to the RIBF for two months. The power of the microwaves fluctuated slowly in the range of 870-1250 W, which influenced the beam current from the ion source. This fluctuation was caused by a slight change of the current of the solenoid of the gyrotron depending on the room temperature. We replaced the power supply with new one which has a current stability of 10ppm per day, and stabilized the microwave power in the range of 5% in the operation of 2 kW successfully.

TUPP18	DECRIS-5 Ion Source for DC-110 Cyclotron Complex Results of the First Tests	ion, injection, extraction, ECRIS	74
	A.A. Efremov, V. Bekhterev, S.L. Bogomolov, Yu.K. Kostyukhov, N. Lebedev, V.N. Loginov, Yu. Yazvitsky JINR, Dubna, Moscow Region, Russia V. Mironov KVI, Groningen, The Netherlands
	The project of the DC-110 cyclotron facility to provide applied research in the nanotechnologies (track pore membranes, surface modification of materials, etc.) has been designed by the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research (Dubna). The facility includes the isochronous cyclotron DC-110 for accelerating the intense Ar, Kr, Xe ion beams with 2.5 MeV/nucleon fixed energy. The cyclotron is equipped with system of axial injection and ECR ion source DECRIS-5, operating at the frequency of 18 GHz. The main parameters of DECRIS-5 ion source and results of the first tests are presented in this report.

WEYO02	Experimental Results: Charge-state and Current-density Distribution at the Plasma Electrode of an ECR Ion Source	ion, plasma, extraction, ECR	101
	L. Panitzsch, T. Peleikis, M. Stalder, R.F. Wimmer-Schweingruber IEAP, Kiel, Germany
	We have measured the current-density in very close vicinity (15 mm downstream) of the plasma electrode of our hexapole-geometry electron-cyclotron-resonance ion source (ECRIS). For this, we equipped our 3D-movable puller electrode with a customized Faraday Cup (FC) inside. To achieve high spatial resolution we reduced the aperture of the puller electrode to only 0.5 mm. Thus, the source-region of the extracted ion beam is limited to a very small area of the plasma electrode's hole (d = 4 mm). The information about the charge-state distribution and the current density in the plane of the plasma electrode is conserved in the ion beam and was scanned by remotely moving the small-aperture puller electrode (incl. FC) across the aperture of the plasma electrode. From additional m/q- measurements for the different positions we can deduce that different ion charge-states are grouped into bloated triangles of different sizes but with the same orientation in the plane of the plasma electrode with the current density peaking at the centre. This confirms simulations by various groups as well as some emittance measurements, but adds spatial resolution for the different charge-states.
	Slides WEYO02 [2.298 MB]

WEYO03	Ion Beam Extraction from Magnetized Plasma	plasma, ion, electron, extraction	106
	P. Spädtke, R. Lang, J. Mäder, F. Maimone, J. Roßbach, K. Tinschert GSI, Darmstadt, Germany
	With increasing the total extracted current for any ion source, the optimisation of the extraction system becomes more important, because of the space charge effect. Several attempts have been made in the past to simulate the extraction from an Electron Cyclotron Resonance Ion Source (ECRIS) in a correct way. Most of these attempts failed, because they were not able to reproduce the experimental results. The best model up to now is given by the following procedure: tracing the magnetic field lines through the extraction aperture, looking where these field lines are coming from; using these coordinates of the magnetic field line as starting points for ions to be extracted; the initial current of each trajectory is determined by theoretical assumptions about the plasma or by a plasma simulation; Child's law is applicable locally only in direction of the magnetic field, if no emission limited flow is present.
	Slides WEYO03 [16.955 MB]

WEZO02	Design of new 18 GHz ECR for RIKEN RIBF	ion, plasma, ECRIS, solenoid	114
	K. Ozeki, Y. Higurashi, T. Nakagawa, J. Ohnishi RIKEN Nishina Center, Wako, Japan
	In RIKEN RIBF, we plan to install a new 18 GHz ECR ion source, which supply the intense beam of highly charged heavy ion beam into the linear accelerator RILAC. By equipping two ion sources, it is expected to be able to develop new beams while we produce the beam for the experiment of RIBF. Based on the structure of 18 GHz ECR ion source which have been developed in RIKEN, this ion source has additional features as follows: Owing to three solenoid coils, Bext can be adjusted while Bmin is fixed to an optimum value. We adopt the variable frequency (17.2-18.4 GHz) RF power source. Therefore, further enhancement of the beam intensity is expected because the frequency band suited to a size of plasma chamber is selectable, In order to simplify the maintenance work, we improved a structure of the chamber. In this contribution, we report the design of new ion source in detail.
	Slides WEZO02 [10.113 MB]

WEPP02	Relationship of Performance and RF Resonance Modes	ion, ECR, resonance, plasma	121
	T. Hattori, A. Kitagawa, M. Muramatsu NIRS, Chiba-shi, Japan N. Hayashizaki RLNR, Tokyo, Japan
	The performance of Electron Cyclotron Resonance (ECR) ion source depends on the operation frequency, the magnetic mirror field, the maltipole field, the mirror ratio, the ECR zone and others. We studied the relationship of performance and operation frequency in ECR ion source (HiECR-3). The performance (beam intensity of Ar⁹⁺ ion) was measured according to change of frequency from 9.7 to 11.7 GHz in fixed magnetic field of HiECR ion source. We measured resonant frequencies of plasma chamber of HiECR ion source in condition of no plasma (current of mirror coils is zero). The data of intensity of Ar⁹⁺ related to measured resonant frequencies. Their resonant modes were checked with a 3D electromagnetic simulator (High Frequency Structure Simulator). As a result, it became clear that the performance of the ion source depends on electric-field distribution of the RF resonant mode.

WEPP13	Development Update of the LECR4 Ion Source - Dragon at IMP	ion, sextupole, ECR, extraction	133
	W. Lu, B.H. Ma, L.T. Sun, H. Wang, D. Xie, X.Z. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China L. Ruan, B. Xiong IEE, Beijing, People's Republic of China
	A new room temperature ECR ion source, LECR4-DRAGON to operate at 18 GHz, is under development for the SSC-LINAC project at IMP. In comparison to other room temperature ECRISs, one unique feature of LECR4-DRAGON is that its plasma chamber is of ID 126 mm that is the biggest chamber for a room temperature ECRIS and the same as the superconducting ECR ion source SECRAL. Because the project funding requests testing a different magnet cooling scheme, solid quadrate copper coils cooled by medium evaporation at about 50^oC are to be used to produce a maximum axial magnetic field of about 2.5 T at injection and 1.4 T at the extraction, which are similar to SECRAL operating at 18 GHz. Furthermore, a large bore non-Halbach permanent sextupole with staggered structure has been under fabrication which can produce a radial magnetic field reaching 1.5 T at the plasma chamber wall for operation at 18 GHz. The progress updates and discussions of this new ion source will be presented in this paper.

WEPP14	An Advanced Injection System of Light Ions (AISLI) for Dielectric Wall Accelerator	ion, proton, emittance, ECR	136
	S.X. Peng, J. Chen, J.E. Chen, Z.Y. Guo, P.N. Lu, H.T. Ren, Y. Xu, J. Zhao PKU, Beijing, People's Republic of China
	The dielectric wall accelerator (DWA) is a kind of acceleration system that has the ability to accelerate any charge to mass ratio particle with high electric field gradients up to 400 MV/m and very compact dimension, for example d 30 mm x 50 mm. To demonstrate the high gradient tiny acceleration system, a comparable 50 mA/40 keV pulsed H⁺ converge beam injector is required. Based on the experimental results obtained on the test bench, a six electrodes injector was developed at Peking University (PKU). In this paper we will describe the preliminary experimental results as well as the details of the new compact injector which named as An Advanced Injector System of Light Ions (AISLI).
	Poster WEPP14 [3.963 MB]

WEPP15	Metal Ion Beam Production with Improved Evaporation Ovens	ion, operation, ECRIS, plasma	140
	K. Tinschert, R. Lang, J. Mäder, F. Maimone, J. Roßbach GSI, Darmstadt, Germany
	Most of the ion beams delivered by the ECR ion sources at the GSI accelerator facilities are produced from materials in the solid state, which must be transformed into the gaseous state to feed the plasma. The well established method of thermal evaporation has been used by means of two types of resistively heated ovens for metals and solid compounds. The main goal of development is to improve their versatility in terms of lifetime, durability, efficiency, and extended temperature range. Recent investigations and developments include the use of alternative materials for oven components. The main focus has been on the further development of the high temperature oven. A modular construction with improved mechanical dimensional accuracy for more precise and easier mounting has been established. Its optimization for stable long time operation has been continued leading to a lifetime of 6 days for evaporation of Ti at 1750°C. Furthermore the temperature limit could be extended to 2300°C. In addition to the improvements in evaporation technology the technique of microwave frequency tuning could be successfully applied for metal ion operation leading to enhanced ion beam intensities.

WEPP16	Experimental Studies on the ALISES Ion Source at CEA Saclay	plasma, ion, electron, extraction	143
	O. Tuske, O. Delferrière, Y. Gauthier, R. Gobin, F. Harrault, J.L. Jannin CEA/DSM/IRFU, France S. Nyckees CEA/IRFU, Gif-sur-Yvette, France
	The ALISES ion source was originally designed to reduce beam emittance at RFQ entrance by shortened the length of the LEBT. A wide opened magnetic coil at ground potential produces the fringe field needed for the ECR heating at 2.45 GHz frequency. The first part describes the commissioning of the source: Penning discharges inside the accelerating column make the high voltage power supply collapse. Experimental tests with kapton films while discharges occur, and simulations with OPERA-3D code have shown great similarities to detect the location of those discharges and allow us to make the ion source work. The second part of this paper will present the result of low intensity light ion beam production versus the plasma chamber length and radius. Those very preliminary tests give us indications to reduce the ion source dimensions.
	Poster WEPP16 [2.556 MB]

WEPP17	A Multi-Sample Changer Coupled to an ECR Source for AMS Experiments	plasma, laser, ion, ECR	146
	R.C. Vondrasek, T. Palchan, R.C. Pardo, C.E. Peters, M.A. Power, R.H. Scott ANL, Argonne, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. A project using Accelerator Mass Spectrometry (AMS) at the ATLAS facility to measure neutron capture rates on a wide range of actinides in a reactor environment is underway. This project will require the measurement of a large number of samples previously irradiated in the Advanced Test Reactor at Idaho National Laboratory. The AMS technique at ATLAS is based on production of highly-charged positive ions in an electron cyclotron resonance ion source (ECRIS) followed by acceleration in the ATLAS linac. The sample material is introduced into the plasma via laser ablation. This should limit the dependency of material feed rates upon the source material composition as well as minimize cross-talk between samples. A new multi-sample changer has been constructed allowing rapid changes between samples. The sample changer has 20 positions and is capable of moving from one sample to the next in one minute. Details of the sample changer design and operation will be presented.

THXO02	Current Developments of the VENUS Ion Source in Research and Operations	plasma, ion, extraction, cyclotron	153
	J.Y. Benitez, K.Y. Franzen, C.M. Lyneis, L. Phair, M.M. Strohmeier LBNL, Berkeley, California, USA G. Machicoane FRIB, East Lansing, Michigan, USA L.T. Sun IMP, Lanzhou, People's Republic of China
	The VENUS ion source functions as a research and development tool in the ECR community as well as an injector for LBNL's 88-Inch cyclotron. In order to meet the needs of both the ECR community and users at the 88-Inch cyclotron, technology such as ovens and a sputter probe have been developed for introducing metals into the plasma. Using a modified high temperature oven, VENUS has produced 450 eμA of ²³⁸U³³⁺ and 400 eμA of ²³⁸U³⁴⁺, twice the required Uranium beam current needed for FRIB. In addition, after upgrading its high voltage capabilities VENUS produced 11emA of ⁴He²⁺, a capability that remains unparalleled by other ECR ion sources. In addition to its recent record high intensities VENUS is also being developed to deliver low intensity, ultra high charge state ions for the cocktails beams, where many species are produced simultaneously for use by the BASE Facility. ¹²⁴Xe⁴³⁺ is now in regular production for the 16 MeV/u cocktail, and development of ²⁰⁹Bi⁵⁶⁺ for the 10 MeV/u cocktail is in progress and has been accelerated through the 88-Inch cyclotron. This paper presents the latest work towards integrating the VENUS ion source into our research and operational goals.
	Slides THXO02 [8.391 MB]

THXO03	Recent RIKEN 28 GHz SC-ECRIS Results	ion, ECRIS, extraction, ECR	159
	Y. Higurashi, M. Fujimaki, H. Haba, O. Kamigaito, M. Kidera, M. Komiyama, J. Ohnishi, K. Ozeki RIKEN Nishina Center, Wako, Japan T. Aihara, M. Tamura, A. Uchiyama SHI Accelerator Service Ltd., Tokyo, Japan
	For increasing the beam intensity of highly charged heavy ions at RIKEN RIBF, we constructed new SC-ECR ion source. In the spring of 2011, we injected 28GHz microwave into the ion source and obtained first beam. Since then, we made several test experiments for increasing the beam intensity of highly charged Xe and U ion beam, and produced ~60 eμA of U³⁵⁺, ~90 eμA of U³³⁺ at the injected RF power of ~2 kW using sputtering method. In case of Xe²⁵⁺, 250 euA was obtained at RF power of 1.7 kW. Using sputtering method, we produced U³⁵⁺ ion beam longer than one month for the RIBF experiment without break. In the beginning of 2012, we installed additional GM-JT refrigerator to increase the cooling power at 4.2 K, then the total cooling power became higher than 9 W. Using it, we can use higher than 8 W of cooling power for heat load due to the absorbed X-rays. In this summer, we will install the new plasma chamber made of Al for increasing the cooling power. We will also use high temperature oven to increase the U vapor. In this contribution, we report the recent modification of the ion source and test experiments for production of U and Xe ion beam.
	Slides THXO03 [49.487 MB]

THYO03	Design Status of ECR Ion Sources and LEBT for FRIB	ion, ECR, sextupole, solenoid	172
	G. Machicoane, N.K. Bultman, G. Morgan, E. Pozdeyev, X. Rao FRIB, East Lansing, Michigan, USA J.Y. Benitez, C.M. Lyneis LBNL, Berkeley, California, USA L.T. Sun IMP, Lanzhou, People's Republic of China
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The Facility for Rare Isotope Beams at Michigan State University is currently being designed and will provide intense beams of rare isotopes for research in nuclear physics, nuclear astrophysics and study of fundamental interactions. The FRIB driver linac will accelerate all stable isotopes from Oxygen to Uranium to energies beyond 200 MeV/u at beam powers up to 400 kW. In the case of Uranium about 13.3 pμA of U³³⁺ are required from the ion source to reach the maximum beam power on the target. Such current is at the limit of what an ECR ion source can produce and led us to design the FRIB driver linac to accelerate concurrently two charges. The ECR ion source for FRIB will be based on the VENUS ion source developed at Lawrence Berkeley National Laboratory (LBNL). Recent beam measurements done with VENUS have demonstrated that the ion source can actually produce close to 13pμA of U³³⁺ and therefore could possibly meet the current required for FRIB in one charge state. This paper reviews the status of the FRIB ECR ion source and the modifications that have been made to the VENUS ion source design. The Low energy beam line transport (LEBT) will also be presented and discussed.
	Slides THYO03 [6.532 MB]

THYO04	Performance of the ANL ECR Charge Breeder with Low Mass Beams	ion, plasma, injection, ECR	177
	R.C. Vondrasek, S.V. Kutsaev, R.C. Pardo, R.H. Scott ANL, Argonne, USA P. Delahaye, L. Maunoury GANIL, Caen, France
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. The Californium Rare Ion Breeder Upgrade (CARIBU) of the ATLAS superconducting linac facility aims at providing low-energy and reaccelerated neutron-rich radioactive beams to address key nuclear physics and astrophysics questions. These beams are obtained from fission fragments of a Cf-252 source, thermalized and collected into a low-energy particle beam by a helium gas catcher, mass analyzed by an isobar separator, and charge bred with an ECR ion source for acceleration in ATLAS. The charge breeding program had focused on optimizing beams in the mid-mass range, achieving high charge breeding efficiencies of both gaseous and solid species including 14.7% for the radioactive species ¹⁴³Ba²⁷⁺. In an effort to better understand the charge breeding mechanism, we recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Charge breeding efficiencies of 10.1% for ²³Na⁷⁺ and 17.9% for ³⁹K¹⁰⁺ were obtained injecting stable Na⁺ and K⁺ beams from a surface ionization source. Details of these studies will be presented as well as simulations detailing the injection of the low charge state beams into the charge breeder.
	Slides THYO04 [9.178 MB]

FRXA02	All Permanent Magnet ECR Ion Source Development and Operation Status at IMP	ion, ECR, plasma, permanent-magnet	185
	L.T. Sun, Y. Cao, J.Q. Li, J.Y. Li, B.H. Ma, H. Wang, J.W. Xia, D. Xie, W.H. Zhang, X.Z. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China
	All permanent magnet ECR ion sources have many advantages over traditional ECR ion sources composed of several axial room temperature solenoids and one permanent magnet hexapole magnet, which make them the first choice for many heavy ion facilities and platforms. At IMP, three types of all permanent magnet ECR ion sources have been built for different applications, i.e. the very compact ECR ion source LAPECR1 for intense mono or multi charge state ion beam production, the LAPECR2 ion source installed on the 320 kV high voltage multidisciplinary platform, and the LAPECR3 ion source dedicated to C⁵⁺ beam production for the cancer therapy facility. In this paper, after a general discussion of the ion sources' design, the applications and the operation status of the IMP all permanent magnet ECR ion sources will be presented.
	Slides FRXA02 [6.380 MB]

FRYA01	ECRISs at GANIL Today and Tomorrow	ion, ECRIS, target, ECR	195
	P. Jardin, O. Bajeat, C. Barue, C. Canet, P. Delahaye, M. Dubois, M. Dupuis, J.L. Flambard, R. Frigot, C. Leboucher, P. Lehérissier, F. Lemagnen, L. Maunoury, O. Osmond, J. Piot, E.K. Traykov GANIL, Caen, France B.J.P. Gall IPHC, Strasbourg Cedex 2, France C. Peaucelle IN2P3 IPNL, Villeurbanne, France J. Rubert, T. Thuillier LPSC, Grenoble Cedex, France O. Tuske CEA/DSM/IRFU, France
	GANIL (Grand accélérateur National d'Ions Lourds) uses ECRIS for producing stable and radioactive ions since more than 20 years. 2 ECR4 type IS deliver intense multi-charged stable ion beams of gaseous and metallic elements to cyclotrons for post acceleration to energies up to 100 A·MeV. A full permanent magnet ECRIS is also used for producing multi-charged radioactive ion beams in the frame of SPIRAL 1 (Système de Production d'Ions radioactifs Accélérés en Ligne, part 1). For atomic physic experiment, a high performance ECRIS named GTS developed at CENG/ Grenoble (France) is currently used to deliver high intensity, high charge state and low energy ion beams. To extend the range of radioactive ion beams available at GANIL, two ISOL (Isotope Separator On Line) projects are underway (SPIRAL2 and SPIRAL1 upgrade). In the frame of these projects, radiation hard singly-charged ECRIS, Q/A=1/3 ECRIS, 2.45 GHz deuteron ECRIS and permanent magnet TISS (Target Ion Source System) using an ECRIS are in development in parallel. A review of the main uses, current developments and performances obtained or expected with ECRISs at GANIL will be presented.
	Slides FRYA01 [6.926 MB]

FRYA02	Status of ECR Ion Sources for Carbon-ion Radiotherapy in Japan	ion, ECR, operation, extraction	200
	A. Kitagawa, M. Muramatsu NIRS, Chiba-shi, Japan A.G. Drentje KVI, Groningen, The Netherlands T.F. Fujita National Institute of Radiological Sciences, Chiba, Japan M. Kanazawa SAGA HIMAT, Saga, Japan N. Sasaki, W. Takasugi AEC, Chiba, Japan E. Takeshita, S. Yamada Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
	Heavy-ion radiotherapy is successfully carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS) since 1994. Now three facilities are in operation and two are under construction in Japan. Over 8000 cancer patients have already been treated. 140-400 MeV/u carbon beams were selected for the first clinical trials at HIMAC because carbon is one of the best candidates which gives good localized biological dose distribution for the typical conditions, a depth of 10 - 25 cm and a thickness of several cm. Based on the clinical results, all the patients have been treated by carbon beams at present. The ion source needs to realize a stable carbon beam with the same conditions for daily operation. Since operators are usually not specialists of the ion source, the source should not require complicated manual tuning. In addition, shorter maintenance time and cycle are better for a hospital. ECR ion sources are utilized for such requirements in each facility. We report the recent status of the ECR ion sources at heavy-ion radiotherapy facilities in Japan.
	Slides FRYA02 [5.652 MB]

FRYA03	ECRIS Related Research and Development Work at JYFL and Some Future Prospects	ion, plasma, photon, electron	203
	H. A. Koivisto, J. Ärje, T. Kalvas, J.P.O. Komppula, R.J. Kronholm, J.P. Laulainen, O.A. Tarvainen, V. Toivanen JYFL, Jyväskylä, Finland
	Since the last ECR workshop the JYFL ion source group has focused on the plasma research, work on the ion beam formation and transport and development of metal ion beams. The plasma research can be divided into plasma breakdown processes, plasma and ion beam instabilities and afterglow processes. The afterglow and instability experiments will be presented elsewhere in these proceedings [1]. In addition, studies involving in the photoelectric induced electron emission and charge exchange reactions will be briefly discussed and the experiments concerning the resonance properties of empty and plasma loaded cavity will be presented. An improvement in ion beam transport of the JYFL K130 cyclotron facility was achieved as a result of the work performed on ion beam formation. This work will be described in more detailed elsewhere in these proceedings [2]. The MIVOC method and sputtering technique were further studied in order to produce intensive titanium ion beams. As a result, an intensive {50}Ti ion beam was successfully produced with the MIVOC method and interesting behavior regarding the sputtering was noticed. [1] V. Skalyga et al. and O. Tarvainen et al. [2] V. Toivanen et al.
	Slides FRYA03 [4.159 MB]

Paper

Title

Other Keywords

Page

TUXO01

Coupling Microwave Power into ECR Ion Source Plasmas at Frequencies above 20 GHz

plasma, ECR, ion, coupling

1

C.M. Lyneis, J.Y. Benitez, M.M. Strohmeier, D.S. Todd
LBNL, Berkeley, California, USA

Electron Cyclotron Resonance (ECR) ion sources have been built to operate at frequencies from 5 GHz to 28 GHz and typically use a plasma chamber that serves as a multi-mode cavity. For small sources operating at 6 to 14 GHz cavity mode-like behavior has been reported. In these cavities the vacuum mode density is low enough that it may be that the RF power distribution can be understood in terms of excitation of a few modes. The large superconducting ECR ion sources, such as VENUS, operating at higher frequencies have a much greater mode density and very strong damping from plasma microwave adsorption. In this type of source, how the RF is launched into the plasma chamber will strongly affect the microwave coupling and the chamber walls will be less important. The VENUS source uses round over-moded TE01 mode waveguide to couple to the plasma, while most modern fusion devices use quasi-gaussian HE11 waves for injection into plasmas. In this paper we will describe the potential advantages of applying this technology to superconducting ECR ion sources as well as designs for doing so with VENUS.

Slides TUXO01 [18.302 MB]

TUXO02

An Experimental Study of ECRIS Plasma Stability and Oscillation of Beam Current

ECR, plasma, ion, ECRIS

5

O.A. Tarvainen, T. Kalvas, H. A. Koivisto, J.P.O. Komppula, V. Toivanen
JYFL, Jyväskylä, Finland
C.M. Lyneis, M.M. Strohmeier
LBNL, Berkeley, California, USA

The stability of oxygen ion beams extracted from ECR ion sources has been studied with the superconducting ion source VENUS at LBNL and with the A-ECR type 14 GHz ECRIS at JYFL. Discrete Fourier transform has been used for characterizing beam current oscillations in kHz range exhibited by both ion sources. The effect of source parameters on the frequency and amplitude of the oscillations is discussed. It was found that double frequency heating affects the oscillation frequency, biased disc can be used to mitigate the amplitude of beam current fluctuations, increasing B-minimum results to pronounced instabilities and operating the ion source with significantly higher mirror ratio than suggested by ECRIS scaling laws yields the most stable ion beams. It is argued that the observed beam current fluctuations are correlated with plasma instabilities. A 'roadmap' for identifying the plasma instability mechanisms responsible for beam current fluctuations is presented.

Slides TUXO02 [2.195 MB]

TUXO03

Two-frequency Heating Technique for Stable ECR Plasma

plasma, ion, ECR, ECRIS

10

A. Kitagawa, M. Muramatsu
NIRS, Chiba-shi, Japan
S. Biri, R. Rácz
ATOMKI, Debrecen, Hungary
T.F. Fujita
National Institute of Radiological Sciences, Chiba, Japan
Y. Kato
Osaka University, Graduate School of Engineering, Osaka, Japan
N. Sasaki, W. Takasugi
AEC, Chiba, Japan

As a method to improve highly charged ion production, a technique to feed multiple microwaves with different frequencies is well-known. However the reason is not made sufficiently clear. Our group studied with two frequencies close together with a power of 600 W over by 18 GHz NIRS-HEC ECR ion source installed in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). As a result, it was revealed that the improvement of output beam current depends on the total power. In this case it seems that the two-frequency heating technique carries the advantage that the plasma instability at high microwave power is relieved. The effectiveness of an additional microwave depends on its frequency. It is necessary to optimize an additional frequency precisely; several tens MHz step against 18 GHz. The optimized frequency is directly influenced by the magnetic configuration. The necessary requirements for an additional microwave and the procedure of optimization in order to obtain a large advantage will be discussed.

Slides TUXO03 [1.590 MB]

TUYO02

Control of the Plasma Transversal Losses, Caused by MHD Instabilities, in Open Mirror Magnetic Trap of the ECRIS: Recent Experiments on SMIS 37 Setup

plasma, ion, ECR, electron

18

V. Sidorov, I. Izotov, S. Razin, V. Skalyga, V. Zorin
IAP/RAS, Nizhny Novgorod, Russia

Funding: This work was partially performed in the framework of the Federal Targeted Program 'Scientific and Educational Personnel of the Innovative Russia' for 2009-2013
This work is a continuation of the experiments described in [1, 2] and aimed at the investigation of the new conceptions of MHD stabilization of plasma in open axisymmetric traps, specifically, it is aimed at the investigation of the shear flow influence on the transport control in open mirror traps. As in previous experiments, shear flow was created by limiter-electrode with bias potential according to the vacuum chamber. Plasma density structure in radial and azimuthal directions was studied. Mode structure of the perturbations was investigated. Substantial sharp shift of the plasma density maximum to the system axis with bias potential growth was demonstrated. It was shown, that the value of the bias potential that corresponds to the plasma density profile shift grows with the magnetic field growth that can be interpreted as the electron temperature growth. Some theoretical estimations of the influence of the transversal losses decrease on plasma parameters were made.
[1] A.Sidorov, P.Bagryansky, A.Beklemishev et al. Trans. Fusion Sci. and Technology, 59, 112, (2011).
[2] I.Izotov, S.Razin, A.Sidorov et al. Rev. Sci. Instrum., 83, 02A318 (2012).

Slides TUYO02 [1.542 MB]

TUZO02

Detailed Investigation of the 4D Phase-Space of an Ion Beam

ion, emittance, dipole, cyclotron

30

H.R. Kremers, J.P.M. Beijers, S. Brandenburg, V. Mironov, S. Saminathan
KVI, Groningen, The Netherlands

A second order transfer matrix is calculated, which is used in the calculation of a 4D phase-space distribution of a 24.6 keV He¹⁺ beam. The calculated distribution matches a 4D phase-space distribution measured with the KVI pepper pot emittance meter. The pepper pot emittance meter is installed in the image plane of a dipole magnet acting as a charge-state analyser directly downstream the KVI AECR ion source. From the second order transfer matrix simple analytical equations are derived by retaining the terms for angular coefficients. These simple equations describe the main features of the phase-space correlations in the image plane. The equations show also that the subset of the 4D phase-space distribution, selected by one pepper pot aperture, results in multiple beam-lets. Due to this successful matrix modelling we conclude that the 4D phase-space distribution measured is fully determined by the ionoptical properties of the magnet.

Slides TUZO02 [6.348 MB]

TUPP01

Quantitative Determination of ¹⁴⁶Sm/¹⁴⁷Sm Ratios by Accelerator Mass Spectrometry with an ECR Ion Source and Linear Acceleration for ¹⁴⁶Sm Half-Life Measurement

ion, ECR, detector, target

43

N. Kinoshita
UTTAC, Tsukuba, Ibaraki, Japan
P. Collon, Y. Kashiv, D. Robertson, C.J. Schmitt, X.D. Tang
University of Notre Dame, Indiana, USA
C. Deibel
MSU, East Lansing, Michigan, USA
C. Deibel, B. DiGiovine, J.P. Greene, D. Henderson, C.L. Jiang, S.T. Marley, R.C. Pardo, E. Rehm, R.H. Scott, R.C. Vondrasek
ANL, Argonne, USA
T. Nakanishi, A. Yokoyama
Kanazawa University, Kanazawa, Japan
M. Paul
The Hebrew University of Jerusalem, The Racah Institute of Physics, Jerusalem, Israel

Funding: Supported by U.S. DOE, Office of Nuclear Physics, contract No. DE-AC02-06CH11357, NSF JINA Grant Nr. PHY0822648 and Science Research Prog. of Japan Society for the Promotion of Science (20740161)
The alpha-decaying ¹⁴⁶Sm nuclide is used for chronology of the Solar System and silicate mantle differentiation in planets. We performed a new determination of 146Sm half-life by measuring ¹⁴⁶Sm/¹⁴⁷Sm alpha activity and atom ratios in ¹⁴⁷Sm activated via (g,n), (n,2n) and (p,2n) reactions and obtained a value (68 Myr), smaller than that adopted so far (103 Myr), with important geochemical implications*. The experiment required determination of ¹⁴⁶Sm/¹⁴⁷Sm ratios by high-energy (6 MeV/u) accelerator mass spectrometry to discriminate ¹⁴⁶Sm from isobaric ¹⁴⁶Nd contaminant. Activated Sm targets were dissolved, chemically purified and reconverted to metallic Sm. Sputter cathodes, made by pressing the Sm metal into high-purity Al holders, were used to feed the Argonne ECR ion source. ¹⁴⁶Sm²²⁺, ¹⁴⁷Sm²²⁺ ions were alternately injected and accelerated with the ATLAS linac by proper scaling of ion source and accelerator components. A tightly-fitted quartz cylindrical liner was inserted in the ECR plasma chamber to reduce contamination from the walls. ¹⁴⁶Sm ions were eventually counted in a gas-filled magnet and ¹⁴⁷Sm ions either measured as charge current or counted after proper attenuation.
* N. Kinoshita et al., Science 334, 1614 (2012)

TUPP03

Integration of a Third Ion Source for Heavy Ion Radiotherapy at HIT

ion, operation, extraction, emittance

46

T.W. Winkelmann, A.B. Büchel, R. Cee, A. Gaffron, Th. Haberer, J.M. Mosthaf, B. Naas, A. Peters, J. Schreiner
HIT, Heidelberg, Germany

HIT is the first European hospital based facility for scanned proton and heavy ion radiotherapy. In 2009 the clinical operation started, since then more than 800 patients were treated in the facility. In a 24/7 operation scheme two 14.5 GHz electron cyclotron resonance ion sources are routinely used to produce protons and carbon ions. In the near future a helium beam for regular patient treatment is requested. The modification of the low energy beam transport line (LEBT) for the integration of a third ion source into the production facility was done in winter 2011. For beam quality improvement with a smaller emittance at the same current we designed and tested a new extraction system at the testbench and equipped the source for protons and helium with this optimized system. This paper will present results of the LEBT modification and gives an outlook to further enhancements at the HIT ion source testbench.

TUPP04

Design of a Compact ECR Ion Source for Various Ion Production

ion, extraction, ECR, plasma

49

M. Muramatsu, S. Hojo, Y. Iwata, K. Katagiri, A. Kitagawa, Y. Sakamoto, S. Sato
NIRS, Chiba-shi, Japan
A.G. Drentje
KVI, Groningen, The Netherlands
T.F. Fujita
National Institute of Radiological Sciences, Chiba, Japan

Compact ECR ion source with all permanent magnets, so called Kei2, was developed for high energy carbon ion therapy facility at National Institute of Radiological Sciences. Kei2 source was design for production of only carbon ion for medical treatment. A copy of Kei2, so called KeiGM is used for Gunma University. Kei series are optimized for carbon ion production. In order to produce various ion beams for research, we design a new compact ECR ion source, so called Kei3. Kei3 is designed based on previous Kei series. In addition, there are three important points: 1) Movable beam extraction system for various extraction current densities, 2) An evaporator and MIVOC method for production of ions from solid materials and metal, and 3) Biased disk method and double frequency heating method for heavier ions. Same permanent magnets and microwave system will be used for easy maintenance and the cost effectiveness. Design of the Kei3 source will be described in this paper.

TUPP17

Installation and Operation of a 28 GHz Gyrotron for the RIKEN Superconducting ECR Ion Source

cathode, ion, detector, power-supply

71

J. Ohnishi, Y. Higurashi, T. Nakagawa
RIKEN Nishina Center, Wako, Japan

The RIKEN 28-GHz ECRIS uses a gyrotron microwave source fabricated by Mitsubishi Electric Corporation. The maximum output power is 10 kW. The gyrotron produces TE02-mode microwaves, which are converted into the TE01 mode by a mode converter. In the first test on the gyrotron performed using a dummy load, we observed the 50-300 Hz ripples of ~500 W in the output power of 1-7 kW, and it was difficult to make a stable operation in the low-power. These ripples were reduced to one-tenth by stabilizing the cathode voltage and then the gyrotron could produce microwaves from < 0.5 kW stably. The operation of the ion source with the 28 GHz gyrotron was started in 2011 and the ion source supplied U and Xe beams to the RIBF for two months. The power of the microwaves fluctuated slowly in the range of 870-1250 W, which influenced the beam current from the ion source. This fluctuation was caused by a slight change of the current of the solenoid of the gyrotron depending on the room temperature. We replaced the power supply with new one which has a current stability of 10ppm per day, and stabilized the microwave power in the range of 5% in the operation of 2 kW successfully.

TUPP18

DECRIS-5 Ion Source for DC-110 Cyclotron Complex Results of the First Tests

ion, injection, extraction, ECRIS

74

A.A. Efremov, V. Bekhterev, S.L. Bogomolov, Yu.K. Kostyukhov, N. Lebedev, V.N. Loginov, Yu. Yazvitsky
JINR, Dubna, Moscow Region, Russia
V. Mironov
KVI, Groningen, The Netherlands

The project of the DC-110 cyclotron facility to provide applied research in the nanotechnologies (track pore membranes, surface modification of materials, etc.) has been designed by the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research (Dubna). The facility includes the isochronous cyclotron DC-110 for accelerating the intense Ar, Kr, Xe ion beams with 2.5 MeV/nucleon fixed energy. The cyclotron is equipped with system of axial injection and ECR ion source DECRIS-5, operating at the frequency of 18 GHz. The main parameters of DECRIS-5 ion source and results of the first tests are presented in this report.

WEYO02

Experimental Results: Charge-state and Current-density Distribution at the Plasma Electrode of an ECR Ion Source

ion, plasma, extraction, ECR

101

L. Panitzsch, T. Peleikis, M. Stalder, R.F. Wimmer-Schweingruber
IEAP, Kiel, Germany

We have measured the current-density in very close vicinity (15 mm downstream) of the plasma electrode of our hexapole-geometry electron-cyclotron-resonance ion source (ECRIS). For this, we equipped our 3D-movable puller electrode with a customized Faraday Cup (FC) inside. To achieve high spatial resolution we reduced the aperture of the puller electrode to only 0.5 mm. Thus, the source-region of the extracted ion beam is limited to a very small area of the plasma electrode's hole (d = 4 mm). The information about the charge-state distribution and the current density in the plane of the plasma electrode is conserved in the ion beam and was scanned by remotely moving the small-aperture puller electrode (incl. FC) across the aperture of the plasma electrode. From additional m/q- measurements for the different positions we can deduce that different ion charge-states are grouped into bloated triangles of different sizes but with the same orientation in the plane of the plasma electrode with the current density peaking at the centre. This confirms simulations by various groups as well as some emittance measurements, but adds spatial resolution for the different charge-states.

Slides WEYO02 [2.298 MB]

WEYO03

Ion Beam Extraction from Magnetized Plasma

plasma, ion, electron, extraction

106

P. Spädtke, R. Lang, J. Mäder, F. Maimone, J. Roßbach, K. Tinschert
GSI, Darmstadt, Germany

With increasing the total extracted current for any ion source, the optimisation of the extraction system becomes more important, because of the space charge effect. Several attempts have been made in the past to simulate the extraction from an Electron Cyclotron Resonance Ion Source (ECRIS) in a correct way. Most of these attempts failed, because they were not able to reproduce the experimental results. The best model up to now is given by the following procedure: tracing the magnetic field lines through the extraction aperture, looking where these field lines are coming from; using these coordinates of the magnetic field line as starting points for ions to be extracted; the initial current of each trajectory is determined by theoretical assumptions about the plasma or by a plasma simulation; Child's law is applicable locally only in direction of the magnetic field, if no emission limited flow is present.

Slides WEYO03 [16.955 MB]

WEZO02

Design of new 18 GHz ECR for RIKEN RIBF

ion, plasma, ECRIS, solenoid

114

K. Ozeki, Y. Higurashi, T. Nakagawa, J. Ohnishi
RIKEN Nishina Center, Wako, Japan

In RIKEN RIBF, we plan to install a new 18 GHz ECR ion source, which supply the intense beam of highly charged heavy ion beam into the linear accelerator RILAC. By equipping two ion sources, it is expected to be able to develop new beams while we produce the beam for the experiment of RIBF. Based on the structure of 18 GHz ECR ion source which have been developed in RIKEN, this ion source has additional features as follows:

Owing to three solenoid coils, Bext can be adjusted while Bmin is fixed to an optimum value.
We adopt the variable frequency (17.2-18.4 GHz) RF power source. Therefore, further enhancement of the beam intensity is expected because the frequency band suited to a size of plasma chamber is selectable,
In order to simplify the maintenance work, we improved a structure of the chamber.

In this contribution, we report the design of new ion source in detail.

Slides WEZO02 [10.113 MB]

WEPP02

Relationship of Performance and RF Resonance Modes

ion, ECR, resonance, plasma

121

T. Hattori, A. Kitagawa, M. Muramatsu
NIRS, Chiba-shi, Japan
N. Hayashizaki
RLNR, Tokyo, Japan

The performance of Electron Cyclotron Resonance (ECR) ion source depends on the operation frequency, the magnetic mirror field, the maltipole field, the mirror ratio, the ECR zone and others. We studied the relationship of performance and operation frequency in ECR ion source (HiECR-3). The performance (beam intensity of Ar⁹⁺ ion) was measured according to change of frequency from 9.7 to 11.7 GHz in fixed magnetic field of HiECR ion source. We measured resonant frequencies of plasma chamber of HiECR ion source in condition of no plasma (current of mirror coils is zero). The data of intensity of Ar⁹⁺ related to measured resonant frequencies. Their resonant modes were checked with a 3D electromagnetic simulator (High Frequency Structure Simulator). As a result, it became clear that the performance of the ion source depends on electric-field distribution of the RF resonant mode.

WEPP13

Development Update of the LECR4 Ion Source - Dragon at IMP

ion, sextupole, ECR, extraction

133

W. Lu, B.H. Ma, L.T. Sun, H. Wang, D. Xie, X.Z. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China
L. Ruan, B. Xiong
IEE, Beijing, People's Republic of China

A new room temperature ECR ion source, LECR4-DRAGON to operate at 18 GHz, is under development for the SSC-LINAC project at IMP. In comparison to other room temperature ECRISs, one unique feature of LECR4-DRAGON is that its plasma chamber is of ID 126 mm that is the biggest chamber for a room temperature ECRIS and the same as the superconducting ECR ion source SECRAL. Because the project funding requests testing a different magnet cooling scheme, solid quadrate copper coils cooled by medium evaporation at about 50^oC are to be used to produce a maximum axial magnetic field of about 2.5 T at injection and 1.4 T at the extraction, which are similar to SECRAL operating at 18 GHz. Furthermore, a large bore non-Halbach permanent sextupole with staggered structure has been under fabrication which can produce a radial magnetic field reaching 1.5 T at the plasma chamber wall for operation at 18 GHz. The progress updates and discussions of this new ion source will be presented in this paper.

WEPP14

An Advanced Injection System of Light Ions (AISLI) for Dielectric Wall Accelerator

ion, proton, emittance, ECR

136

S.X. Peng, J. Chen, J.E. Chen, Z.Y. Guo, P.N. Lu, H.T. Ren, Y. Xu, J. Zhao
PKU, Beijing, People's Republic of China

The dielectric wall accelerator (DWA) is a kind of acceleration system that has the ability to accelerate any charge to mass ratio particle with high electric field gradients up to 400 MV/m and very compact dimension, for example d 30 mm x 50 mm. To demonstrate the high gradient tiny acceleration system, a comparable 50 mA/40 keV pulsed H⁺ converge beam injector is required. Based on the experimental results obtained on the test bench, a six electrodes injector was developed at Peking University (PKU). In this paper we will describe the preliminary experimental results as well as the details of the new compact injector which named as An Advanced Injector System of Light Ions (AISLI).

Poster WEPP14 [3.963 MB]

WEPP15

Metal Ion Beam Production with Improved Evaporation Ovens

ion, operation, ECRIS, plasma

140

K. Tinschert, R. Lang, J. Mäder, F. Maimone, J. Roßbach
GSI, Darmstadt, Germany

Most of the ion beams delivered by the ECR ion sources at the GSI accelerator facilities are produced from materials in the solid state, which must be transformed into the gaseous state to feed the plasma. The well established method of thermal evaporation has been used by means of two types of resistively heated ovens for metals and solid compounds. The main goal of development is to improve their versatility in terms of lifetime, durability, efficiency, and extended temperature range. Recent investigations and developments include the use of alternative materials for oven components. The main focus has been on the further development of the high temperature oven. A modular construction with improved mechanical dimensional accuracy for more precise and easier mounting has been established. Its optimization for stable long time operation has been continued leading to a lifetime of 6 days for evaporation of Ti at 1750°C. Furthermore the temperature limit could be extended to 2300°C. In addition to the improvements in evaporation technology the technique of microwave frequency tuning could be successfully applied for metal ion operation leading to enhanced ion beam intensities.

WEPP16

Experimental Studies on the ALISES Ion Source at CEA Saclay

plasma, ion, electron, extraction

143

O. Tuske, O. Delferrière, Y. Gauthier, R. Gobin, F. Harrault, J.L. Jannin
CEA/DSM/IRFU, France
S. Nyckees
CEA/IRFU, Gif-sur-Yvette, France

The ALISES ion source was originally designed to reduce beam emittance at RFQ entrance by shortened the length of the LEBT. A wide opened magnetic coil at ground potential produces the fringe field needed for the ECR heating at 2.45 GHz frequency. The first part describes the commissioning of the source: Penning discharges inside the accelerating column make the high voltage power supply collapse. Experimental tests with kapton films while discharges occur, and simulations with OPERA-3D code have shown great similarities to detect the location of those discharges and allow us to make the ion source work. The second part of this paper will present the result of low intensity light ion beam production versus the plasma chamber length and radius. Those very preliminary tests give us indications to reduce the ion source dimensions.

Poster WEPP16 [2.556 MB]

WEPP17

A Multi-Sample Changer Coupled to an ECR Source for AMS Experiments

plasma, laser, ion, ECR

146

R.C. Vondrasek, T. Palchan, R.C. Pardo, C.E. Peters, M.A. Power, R.H. Scott
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
A project using Accelerator Mass Spectrometry (AMS) at the ATLAS facility to measure neutron capture rates on a wide range of actinides in a reactor environment is underway. This project will require the measurement of a large number of samples previously irradiated in the Advanced Test Reactor at Idaho National Laboratory. The AMS technique at ATLAS is based on production of highly-charged positive ions in an electron cyclotron resonance ion source (ECRIS) followed by acceleration in the ATLAS linac. The sample material is introduced into the plasma via laser ablation. This should limit the dependency of material feed rates upon the source material composition as well as minimize cross-talk between samples. A new multi-sample changer has been constructed allowing rapid changes between samples. The sample changer has 20 positions and is capable of moving from one sample to the next in one minute. Details of the sample changer design and operation will be presented.

THXO02

Current Developments of the VENUS Ion Source in Research and Operations

plasma, ion, extraction, cyclotron

153

J.Y. Benitez, K.Y. Franzen, C.M. Lyneis, L. Phair, M.M. Strohmeier
LBNL, Berkeley, California, USA
G. Machicoane
FRIB, East Lansing, Michigan, USA
L.T. Sun
IMP, Lanzhou, People's Republic of China

The VENUS ion source functions as a research and development tool in the ECR community as well as an injector for LBNL's 88-Inch cyclotron. In order to meet the needs of both the ECR community and users at the 88-Inch cyclotron, technology such as ovens and a sputter probe have been developed for introducing metals into the plasma. Using a modified high temperature oven, VENUS has produced 450 eμA of ²³⁸U³³⁺ and 400 eμA of ²³⁸U³⁴⁺, twice the required Uranium beam current needed for FRIB. In addition, after upgrading its high voltage capabilities VENUS produced 11emA of ⁴He²⁺, a capability that remains unparalleled by other ECR ion sources. In addition to its recent record high intensities VENUS is also being developed to deliver low intensity, ultra high charge state ions for the cocktails beams, where many species are produced simultaneously for use by the BASE Facility. ¹²⁴Xe⁴³⁺ is now in regular production for the 16 MeV/u cocktail, and development of ²⁰⁹Bi⁵⁶⁺ for the 10 MeV/u cocktail is in progress and has been accelerated through the 88-Inch cyclotron. This paper presents the latest work towards integrating the VENUS ion source into our research and operational goals.

Slides THXO02 [8.391 MB]

THXO03

Recent RIKEN 28 GHz SC-ECRIS Results

ion, ECRIS, extraction, ECR

159

Y. Higurashi, M. Fujimaki, H. Haba, O. Kamigaito, M. Kidera, M. Komiyama, J. Ohnishi, K. Ozeki
RIKEN Nishina Center, Wako, Japan
T. Aihara, M. Tamura, A. Uchiyama
SHI Accelerator Service Ltd., Tokyo, Japan

For increasing the beam intensity of highly charged heavy ions at RIKEN RIBF, we constructed new SC-ECR ion source. In the spring of 2011, we injected 28GHz microwave into the ion source and obtained first beam. Since then, we made several test experiments for increasing the beam intensity of highly charged Xe and U ion beam, and produced ~60 eμA of U³⁵⁺, ~90 eμA of U³³⁺ at the injected RF power of ~2 kW using sputtering method. In case of Xe²⁵⁺, 250 euA was obtained at RF power of 1.7 kW. Using sputtering method, we produced U³⁵⁺ ion beam longer than one month for the RIBF experiment without break. In the beginning of 2012, we installed additional GM-JT refrigerator to increase the cooling power at 4.2 K, then the total cooling power became higher than 9 W. Using it, we can use higher than 8 W of cooling power for heat load due to the absorbed X-rays. In this summer, we will install the new plasma chamber made of Al for increasing the cooling power. We will also use high temperature oven to increase the U vapor. In this contribution, we report the recent modification of the ion source and test experiments for production of U and Xe ion beam.

Slides THXO03 [49.487 MB]

THYO03

Design Status of ECR Ion Sources and LEBT for FRIB

ion, ECR, sextupole, solenoid

172

G. Machicoane, N.K. Bultman, G. Morgan, E. Pozdeyev, X. Rao
FRIB, East Lansing, Michigan, USA
J.Y. Benitez, C.M. Lyneis
LBNL, Berkeley, California, USA
L.T. Sun
IMP, Lanzhou, People's Republic of China

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The Facility for Rare Isotope Beams at Michigan State University is currently being designed and will provide intense beams of rare isotopes for research in nuclear physics, nuclear astrophysics and study of fundamental interactions. The FRIB driver linac will accelerate all stable isotopes from Oxygen to Uranium to energies beyond 200 MeV/u at beam powers up to 400 kW. In the case of Uranium about 13.3 pμA of U³³⁺ are required from the ion source to reach the maximum beam power on the target. Such current is at the limit of what an ECR ion source can produce and led us to design the FRIB driver linac to accelerate concurrently two charges. The ECR ion source for FRIB will be based on the VENUS ion source developed at Lawrence Berkeley National Laboratory (LBNL). Recent beam measurements done with VENUS have demonstrated that the ion source can actually produce close to 13pμA of U³³⁺ and therefore could possibly meet the current required for FRIB in one charge state. This paper reviews the status of the FRIB ECR ion source and the modifications that have been made to the VENUS ion source design. The Low energy beam line transport (LEBT) will also be presented and discussed.

Slides THYO03 [6.532 MB]

THYO04

Performance of the ANL ECR Charge Breeder with Low Mass Beams

ion, plasma, injection, ECR

177

R.C. Vondrasek, S.V. Kutsaev, R.C. Pardo, R.H. Scott
ANL, Argonne, USA
P. Delahaye, L. Maunoury
GANIL, Caen, France

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
The Californium Rare Ion Breeder Upgrade (CARIBU) of the ATLAS superconducting linac facility aims at providing low-energy and reaccelerated neutron-rich radioactive beams to address key nuclear physics and astrophysics questions. These beams are obtained from fission fragments of a Cf-252 source, thermalized and collected into a low-energy particle beam by a helium gas catcher, mass analyzed by an isobar separator, and charge bred with an ECR ion source for acceleration in ATLAS. The charge breeding program had focused on optimizing beams in the mid-mass range, achieving high charge breeding efficiencies of both gaseous and solid species including 14.7% for the radioactive species ¹⁴³Ba²⁷⁺. In an effort to better understand the charge breeding mechanism, we recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Charge breeding efficiencies of 10.1% for ²³Na⁷⁺ and 17.9% for ³⁹K¹⁰⁺ were obtained injecting stable Na⁺ and K⁺ beams from a surface ionization source. Details of these studies will be presented as well as simulations detailing the injection of the low charge state beams into the charge breeder.

Slides THYO04 [9.178 MB]

FRXA02

All Permanent Magnet ECR Ion Source Development and Operation Status at IMP

ion, ECR, plasma, permanent-magnet

185

L.T. Sun, Y. Cao, J.Q. Li, J.Y. Li, B.H. Ma, H. Wang, J.W. Xia, D. Xie, W.H. Zhang, X.Z. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

All permanent magnet ECR ion sources have many advantages over traditional ECR ion sources composed of several axial room temperature solenoids and one permanent magnet hexapole magnet, which make them the first choice for many heavy ion facilities and platforms. At IMP, three types of all permanent magnet ECR ion sources have been built for different applications, i.e. the very compact ECR ion source LAPECR1 for intense mono or multi charge state ion beam production, the LAPECR2 ion source installed on the 320 kV high voltage multidisciplinary platform, and the LAPECR3 ion source dedicated to C⁵⁺ beam production for the cancer therapy facility. In this paper, after a general discussion of the ion sources' design, the applications and the operation status of the IMP all permanent magnet ECR ion sources will be presented.

Slides FRXA02 [6.380 MB]

FRYA01

ECRISs at GANIL Today and Tomorrow

ion, ECRIS, target, ECR

195

P. Jardin, O. Bajeat, C. Barue, C. Canet, P. Delahaye, M. Dubois, M. Dupuis, J.L. Flambard, R. Frigot, C. Leboucher, P. Lehérissier, F. Lemagnen, L. Maunoury, O. Osmond, J. Piot, E.K. Traykov
GANIL, Caen, France
B.J.P. Gall
IPHC, Strasbourg Cedex 2, France
C. Peaucelle
IN2P3 IPNL, Villeurbanne, France
J. Rubert, T. Thuillier
LPSC, Grenoble Cedex, France
O. Tuske
CEA/DSM/IRFU, France

GANIL (Grand accélérateur National d'Ions Lourds) uses ECRIS for producing stable and radioactive ions since more than 20 years. 2 ECR4 type IS deliver intense multi-charged stable ion beams of gaseous and metallic elements to cyclotrons for post acceleration to energies up to 100 A·MeV. A full permanent magnet ECRIS is also used for producing multi-charged radioactive ion beams in the frame of SPIRAL 1 (Système de Production d'Ions radioactifs Accélérés en Ligne, part 1). For atomic physic experiment, a high performance ECRIS named GTS developed at CENG/ Grenoble (France) is currently used to deliver high intensity, high charge state and low energy ion beams. To extend the range of radioactive ion beams available at GANIL, two ISOL (Isotope Separator On Line) projects are underway (SPIRAL2 and SPIRAL1 upgrade). In the frame of these projects, radiation hard singly-charged ECRIS, Q/A=1/3 ECRIS, 2.45 GHz deuteron ECRIS and permanent magnet TISS (Target Ion Source System) using an ECRIS are in development in parallel. A review of the main uses, current developments and performances obtained or expected with ECRISs at GANIL will be presented.

Slides FRYA01 [6.926 MB]

FRYA02

Status of ECR Ion Sources for Carbon-ion Radiotherapy in Japan

ion, ECR, operation, extraction

200

A. Kitagawa, M. Muramatsu
NIRS, Chiba-shi, Japan
A.G. Drentje
KVI, Groningen, The Netherlands
T.F. Fujita
National Institute of Radiological Sciences, Chiba, Japan
M. Kanazawa
SAGA HIMAT, Saga, Japan
N. Sasaki, W. Takasugi
AEC, Chiba, Japan
E. Takeshita, S. Yamada
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan

Heavy-ion radiotherapy is successfully carried out at the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS) since 1994. Now three facilities are in operation and two are under construction in Japan. Over 8000 cancer patients have already been treated. 140-400 MeV/u carbon beams were selected for the first clinical trials at HIMAC because carbon is one of the best candidates which gives good localized biological dose distribution for the typical conditions, a depth of 10 - 25 cm and a thickness of several cm. Based on the clinical results, all the patients have been treated by carbon beams at present. The ion source needs to realize a stable carbon beam with the same conditions for daily operation. Since operators are usually not specialists of the ion source, the source should not require complicated manual tuning. In addition, shorter maintenance time and cycle are better for a hospital. ECR ion sources are utilized for such requirements in each facility. We report the recent status of the ECR ion sources at heavy-ion radiotherapy facilities in Japan.

Slides FRYA02 [5.652 MB]

FRYA03

ECRIS Related Research and Development Work at JYFL and Some Future Prospects

ion, plasma, photon, electron

203

H. A. Koivisto, J. Ärje, T. Kalvas, J.P.O. Komppula, R.J. Kronholm, J.P. Laulainen, O.A. Tarvainen, V. Toivanen
JYFL, Jyväskylä, Finland

Since the last ECR workshop the JYFL ion source group has focused on the plasma research, work on the ion beam formation and transport and development of metal ion beams. The plasma research can be divided into plasma breakdown processes, plasma and ion beam instabilities and afterglow processes. The afterglow and instability experiments will be presented elsewhere in these proceedings [1]. In addition, studies involving in the photoelectric induced electron emission and charge exchange reactions will be briefly discussed and the experiments concerning the resonance properties of empty and plasma loaded cavity will be presented. An improvement in ion beam transport of the JYFL K130 cyclotron facility was achieved as a result of the work performed on ion beam formation. This work will be described in more detailed elsewhere in these proceedings [2]. The MIVOC method and sputtering technique were further studied in order to produce intensive titanium ion beams. As a result, an intensive {50}Ti ion beam was successfully produced with the MIVOC method and interesting behavior regarding the sputtering was noticed.
[1] V. Skalyga et al. and O. Tarvainen et al.
[2] V. Toivanen et al.

Slides FRYA03 [4.159 MB]