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| MOCO-C02 |
Experiments with Highly Charged Ions at the Paris ECR Ion Source, SIMPA
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32 |
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- C. I. Szabo, D. Attia, A. Gumberidze, P. Indelicato, E.-O. Le Bigot, S. Schlesser
LKB, PARIS
- E. Lamour, J. Merot, C. Prignet, J.-P. Rozet, M. Trassinelli, D. Vernhet
INSP, PARIS
- S. J.C. do Carmo
Coimbra University, Coimbra
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Funding: This work is financed by ANR contract # ANR-06-|B|L|A|N|-|0|2|3|3 SIMSI2-SIMPA.
The full permanent magnet "supernanogan" type ECR (electron cyclotron resonance) ion source, SIMPA (Source d'Ions Multicharges de Paris) has been jointly operated by LKB (Laboratoire Kastler Brossel) and INSP (Institut des NanoSciences de Paris) since 2004. Since this time numerous projects have been started to use the extracted beam in atomic physics and surface physics experiments and the x-ray radiation of the ECR plasma for plasma and atomic physics investigations. In this paper recent achievements will be reported that include the first use of an electrostatic ion trap * for trapping highly charged ions on the beam line of an ECR ion source and electron temperature and density measurements with the help of the observation of the bremsstrahlung spectrum of the electrons in the ECR plasma of the source.** Also a new vacuum double crystal spectrometer *** is under construction in our lab that will allow us to measure the very narrow inner shell transitions of highly charged ions produced in the ECR plasma and provide new x-ray standards with this method for the atomic physics community.
* D. Zajfman, O. Heber, et al. Phys. Rev. A 55, R1577 (1997)
** C. Barue, M. Lamoureux, P. Briand, et al. J. Appl. Phys. 76, 2662 (1994)
*** R. D. Deslattes Rev. Sci. Instrum. 38, 616 (1967)
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Slides
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| MOCO-C03 |
ECRIS on High Voltage Platform for Engineering and Modifications of Materials
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38 |
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- P. Kumar, D. Kanjilal, P. S. Lakshmy, G. Rodrigues
IUAC, New Delhi
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An all permanent magnet electron cyclotron resonance ion source (ECRIS) along with the associated components like 10GHz UHF transmitter, vacuum pumps, vacuum gauges, vacuum pump controllers, gas handling systems with gas bottles, local command and controls systems, etc are set up on a 200kV platform for providing various ion beams having energy in the range of a few tens of keVs to a few MeVs. The capability of ECRIS in producing multiply charged ions is being used for the engineering and modifications of materials, and for understanding charge transfer processes during collision with molecules and dissociation of molecules. The beam currents available from the first few charge states are mainly used for these studies. The 10 GHz all-permanent-magnet ECR ion source on high voltage platform at IUAC has been in regular operation since 2000 for delivering various ion beams for research in materials science, atomic and molecular physics. The salient features of ECRIS based low energy ion beam facility (LEIBF)[*] at IUAC, operational experience of the ion source for producing some of the special beams and some of the exciting experimental results will be presented.
[*]D. Kanjilal, T. Madhu, G. O. Rodrigues, U. K. Rao, C. P. Safvan and A. Roy, Ind. J. of Pure and Appl. Phys. 25 (2001) 39
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Slides
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| MOCO-C04 |
Application of the ATOMKI-ECRIS for Materials Research and Prospects of the Medical Utilization
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41 |
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- S. Biri, I. Ivan, Z. Juhasz, B. Sulik
ATOMKI, Debrecen
- Cs. Hegedüs, S. Kokenyesi, I. Mojzes, J. Palinkas
University Debrecen, Debrecen
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In the ATOMKI ECRIS Laboratory long-term projects were initiated to use heavy ion beams and plasmas for materials research and to explore the possibility of industrial or medical applications of such ions. (1) Based on our earlier experiments with fullerenes and on recent considerable modification of the ATOMKI-ECRIS a collaboration with Japanese institutes resulted in a new ECR-device to produce endohedral fullerenes, namely caged Fe in C60. (2) Titanium bio-implants are covered with fullerene ions to form an intermediate layer between the metal and the organic tissues in order to improve the speed and properties of the connection. Bone cells growth experiments are under way. (3) Laser and electron irradiations showed that the structure and properties (volume, refractive index) of certain amorphous thin films can be effectively modified. We extend these investigations using heavy ion beams, focusing on the effect of the ion charge. (4) Highly charged slow ions can fly through nano-capillaries even for a large misalignment of their axis. Such a phenomenon might get a wide range of applications where ions should be directed, focused, deposited and implanted on a nanoscopic scale.
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Slides
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| MOPO-01 |
Use of an ECR Ion Source for Mass Spectrometry
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55 |
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- M. A.C. Hotchkis, D. Button
ANSTO, Menai
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At ANSTO we have developed an Electron Cyclotron Resonance (ECR) ion source to investigate new concepts for mass spectrometers designed to measure isotopic ratios of elements such as carbon, nitrogen and oxygen. The low pressure ECR plasma presents particular challenges when used for mass spectrometry. The elements we are interested in measuring are typically present as residual gas in vacuum systems and hence we need to achieve ultra-high vacuum throughout our system. Also ECR plasmas generate highly reactive species of these elements which can then bond to internal surfaces. A number of measures have been taken to combat these difficulties. For example, we have shortened the plasma bottle length to minimise the surface area. In making this change we have also discovered that the useful plasma volume is much less than expected. Originally the source was designed with a mirror ratio of around 2.2. With the restricted bottle size, our effective mirror ratio is 1.7 and yet the performance of the source is unaffected. This and other design modifications will be discussed.
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Poster
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| MOPO-03 |
Conceptual Design for a Sputter-type Negative Ion Source Based on Electron Cyclotron Resonance Plasma Heating
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64 |
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- O. A. Tarvainen, S. S. Kurennoy
LANL, Los Alamos, New Mexico
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Funding: This work was supported by the US Department of Energy under Contract Number DE-AC52-06NA25396.
A conceptual design for a negative ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE111 eigenmode at 2.45 GHz. The desired mode is excited with a loop-antenna. The ionization process takes place on a cesiated surface of a biased converter electrode (cathode) sputtered by plasma ions. The ion beam is 'self-extracted' through the plasma. The magnetic field of the source is optimized for both, plasma generation by ECR heating, and beam extraction. The source can be used for production of negative ions ranging from hydrogen to heavy ions. The potential users for the source concept range from large scale accelerator facilities, utilizing H- ion beams, to dc tandem accelerators for heavy ions. The benefits of the source concept compared to widely used filament- and inductively coupled rf-driven sputter-type sources are the lack of consumable parts and low neutral gas pressure minimizing the stripping losses of negative ions. In this article we will focus on the H- production scenarios with the source. The benefits and drawbacks of higher frequency operations are discussed.
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| MOPO-07 |
Measurements of X-Ray Spectra on ECR-II
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73 |
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- B. Cluggish, I. N. Bogatu, J. S. Kim, L. Zhao
Far-Tech, Inc., San Diego, California
- R. C. Pardo, R. H. Scott, R. C. Vondrasek
ANL, Argonne, Illinois
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Funding: This research was performed under a U. S. Dept. of Energy SBIR grant and the Office of Nuclear Physics under contract # DE-AC02-06CH11357.
FAR-TECH, Inc. is developing a non-invasive X-ray spectral diagnostic for monitoring electron cyclotron resonance ion sources (ECRIS). The X-Ray Bremsstrahlung spectrum provides important information about the electron distribution function (EDF), which plays a key role in ionization and production of highly charge ions. To this end, FAR-TECH, Inc. has recently performed extensive measurements of X-ray emission from the ECR-II device in the ATLAS facility at Argonne National Laboratory. Our measurements indicate a significant population of electrons with energies in excess of 100 keV in ECR-II. Furthermore, we find that both the intensity and the shape of the observed spectra are highly correlated with the charge state distribution (CSD) of ions extracted from the ECR-II plasma as measured by a Faraday cup. Measurements of the X-Ray spectra and corresponding CSDs will be presented, as well as analysis of the dependence of the X-ray signal on ECR heating power, working gas pressure, spatial location of the ECR surface, and two-frequency heating. The results will be compared to simulations of ECR-II using our Generalized ECRIS Model (GEM).
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Poster
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| MOPO-08 |
High Energy Component of X-Ray Spectra in ECR Ion Sources
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77 |
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- J. Y. Benitez, D. Leitner, C. M. Lyneis, J. D. Noland, D. S. Todd
LBNL, Berkeley, California
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The 88-Inch Cyclotron at LBNL is home to three powerful ECR ion sources, which operate at a range of heating frequencies from 6.4GHz for the ECR to a combination of 18GHz and 28GHz for the VENUS superconducting ECR. Over the last few years we have investigated the production of x-rays from ECR ion sources with the goal of improving the understanding of the electron energy distribution within these sources. By measuring the spectral temperatures (defined as the reciprocal of the slope of the semi-logarithmic plot of the x-ray energy spectra) and using them as relative indicators of the electron temperatures, different plasma conditions and tuning parameters can be evaluated. A comparison of the axial x-ray spectra measured with the 6.4 GHz ECR ion source to spectra obtained using the 18 and 28GHz VENUS source at equivalent power densities will be presented. In addition, the paper will discuss the experimental setup and analysis of the x-ray measurements. In particular, we will discuss how to remove artifacts from the energy spectra resulting from the interaction of x-rays with the detector in order to accurately represent the x-rays emitted from the source.
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| MOPO-09 |
Permanent Magnet Microwave-Driven Ion Source for Neutron Generation
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85 |
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- Q. Ji, J. W. Kwan, B. A. Ludewigt, M. J. Regis
LBNL, Berkeley, California
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Funding: This work is supported by NA-22 of NNSA under the Department of Energy contract No. DE-AC02-05CH11231.
The basic principle of a neutron generator is to bombard an ion beam of either deuterium or tritium onto a target, where neutrons are produced via the D/T reactions. Compared with RF-driven and Penning Ion Sources commonly used in neutron generators, the 2.45 GHz ECR ion source has the advantages of high power efficiency, high fraction of atomic ions, low gas pressure. For portable application, the ECR source can be built with permanent magnets to minimize size. Results published by Gobin(*) and Song(**) using permanent magnets have shown current densities more than that required in neutron generator applications. In our study, we are trying to simplify the coupling between the magnetron and the plasma chamber in order to achieve either improved system efficiency or compactness. For example, in one case, a pyrex tube is inserted at the end of a wave guide as the plasma chamber. In another case, the plasma chamber has the same cross-sectional dimension as the wave guide for matching the producing of a slit beam. Results such as the current density, ion species, and plasma density profile inside the plasma chamber, as functions of microwave power and gas pressure will be presented.
* R. Gobin et al, Rev. Sci. Instrum. 77, 03B502 (2006)
** Z. Song et al, Rev. Sci. Instrum. 77, 03A305 (2006)
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| MOPO-24 |
High-Resolution Beam-Profile Measurements with a Faraday-Cup Array
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126 |
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- L. Panitzsch, C. Helmke, L. Seimetz, M. Stalder, R. F. Wimmer-Schweingruber
IEAP, Kiel
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The division of extraterrestrial physics at the University of Kiel is establishing a solar wind and supra-thermal particle laboratory which will be used mainly for three reasons: the calibration of space instruments dedicated to measure the solar wind and/or supra-thermal particles, the research of space weathering of dust particles and to study fundamental plasma physics. The laboratory will be able to generate a well-defined and highly charged ion beam at energies from 1 to 450keV/q. Both, calibration of space instruments and dust particle bombardment, need accurate values for the main beam parameters such as current, position, and profile. While the total current is measured by a single Faraday cup (FC), position and profile of the ion beam are acquired by an array of 44 tiny (0.3 mm diameter) Faraday-Cups (FCA) moving through the beam. This allows high resolution of beam current and position, as well as high durability since beam-currents from several hundred pA to a few mA and an incident beam power up to 40W are expected. Here, we present the basics of the detectors hard- and software design in addition to some first results of measurements.
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Poster
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| TUCO-D04 |
Effects of Roll Angles on Halbach Array Efficiency
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173 |
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- D. Maybury, M. M. Scannell, F. E. Spada
ANL, Argonne, Illinois
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The Halbach Array was first described by Mallinson in 1973 (IEEE Transactions on Magnetics, 9, 678-682, 1973). Named after Klaus Halbach, the Berkeley physicist who first applied Halbach arrays in the construction of wigglers, Halbach Arrays have seen increased use in applications that require high weight to magnetic field efficiency. Since magnet geometry is often dictated by the application, weight, and/or cost requirements, the progression of the angular orientation (roll angle) of the array is a frequent target for optimizing array performance. The effect of different roll angles of a magnet system is studied here on a canonical linear array modeled with two different magnet alloys – one high-energy, low-coercivity alloy, and one high-coercivity alloy. All models studied are comprised of square cross-sections. The integrated flux on each side of the array is compared for efficiency, while the half-maximum distances are compared for projection strength. To validate the model results, the candidate arrays are physically constructed, measured and compared to the modeled outcomes.
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Slides
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| THCO-A02 |
Systematic Comparison Between a Pepperpot and an ALLISON Emittance Meter
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204 |
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- H. R. Kremers, J. P.M. Beijers, S. Brandenburg, S. Saminathan
KVI, Groningen
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We discuss a new and versatile emittance meter recently built at KVI. The instrument measures 4D phase-space distributions of low-energy multiply-charged ion beams by scanning a vertical array of 20 micrometer diameter holes horizontally through the beam. The transmitted beamlets are detected with a MCP-CCD camera combination. The emittance meter can measure the full 4D emittance in less than five minutes. We will present a series of emittance measurements, including a systematic comparison with an Allison emittance scanner performed at ISN, Grenoble with the A-Phoenix source, confirming the measurement principle as well as the additional feature to measure the full four dimensional phase-space.
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Slides
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