IPAC2018 - List of Keywords (ISOL)

Paper	Title	Other Keywords	Page
MOPMF043	Tuning of CLIC-Final Focus System 3 TeV Baseline Design Under Static and Dynamic Imperfections	luminosity, collider, linear-collider, simulation	196
	E. Marín, A. Latina, J. Pfingstner, D. Schulte, R. Tomás CERN, Geneva, Switzerland J. Pfingstner University of Oslo, Oslo, Norway
	In this paper we present the tuning study of the Compact Linear Collider - Final Focus System (CLIC-FFS) 3~TeV baseline design under static and dynamic imperfections for the first time. The motion of the FFS magnets due to ground motion and the impact of active and passive mechanisms envisaged to stabilize both e^- and e⁺ systems are described. It is found that the Pre-isolator required for stabilization of the Final Doublet drives the performance of the collider at the final stages of the tuning process. The obtained tuning performance depending on the stabilization techniques are discussed in detail.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF043
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TUPAF041	Residual Gas Ions Characterization from the REXEBIS	detector, rfq, experiment, electron	784
	N. Bidault, M.L. Lozano, J.A. Rodriguez CERN, Geneva, Switzerland
	The Isotope mass Separator On-Line DEvice (ISOLDE) is a user facility located at CERN where Radioactive Ion Beams (RIBs) are produced from proton collisions onto a target, mass separated and transported to user experimental stations either directly at low energy or after being post- accelerated, notably for nuclear physics studies. Prior to acceleration through the REX/HIE-ISOLDE linear acceler- ator, the ion beam is accumulated, bunched and cooled in a Penning trap (REXTRAP) and afterwards charge-bred in an Electron Beam Ion Source (REXEBIS). Multi-charged radioactive species of interest are then selected by a mass-to- charge (A/q) ratio separator dipole in the Low Energy Beam Transfer Line (LEBT). A method is presented to character- ize the Residual Gas Ion (RGI) background contamination for diﬀerent operational conditions of the REXEBIS. More particularly, a discussion is held about the inﬂuence of the conﬁnement time inside the charge-breeder on the residual gas spectrum. Finally, a method to identify sub-pico-Ampere contaminants is demonstrated.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF041
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TUPAF042	Characterization of the Beam Energy Spread at the REX/HIE-ISOLDE Linac	cavity, linac, experiment, detector	787
	M.L. Lozano, N. Bidault, E. Fadakis, M.A. Fraser, E. Matli, J.A. Rodriguez CERN, Geneva, Switzerland
	ISOLDE is an on-line radioactive isotope separator located at CERN that works by colliding protons accelerated in the PS Booster into a fixed target and by separating the resultant ionized isotopes using a magnetic separator. The completion of the HIE-ISOLDE superconducting linac allows the acceleration of these ions to energy levels that were not reachable before, opening the door to new experiments in different fields. These experiments often have special requirements in terms of beam intensity and purity, transverse emittance or energy spread. A possible way to reduce the energy spread of the beam delivered to the experimental stations is to use one or more of the superconducting cavities as bunchers. The main results of several tests conducted during the last beam commissioning campaign prove that this mode of operation is feasible and will be presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF042
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TUPAL051	Program for High-Intensity RFQ Design With Matched and Equipartitioned Design Strategy	rfq, emittance, linac, resonance	1126
	H.P. Li, M.J. Easton, Q. Fu, P.P. Gan, Y.R. Lu, Q.Y. Tan, Z. Wang, K. Zhu PKU, Beijing, People's Republic of China
	The deuteron driver accelerator of the Beijing Iso-tope Separation On-Line (BISOL) facility will acceler-ate and deliver a 20 mA deuteron beam to the targets with an energy of 40 MeV. As the injector of the driver linac, an RFQ is required to bunch and accelerate the 20 mA deuteron beam to 3 MeV with very high beam quality. In order to fulfil these requirements and re-duce time spent on optimization, an RFQ design pro-gram named RFQEP has been developed to generate the input file for the PARMTEQM code. In this program, the ‘matched and equipartitioned' design strategy is adopted to prevent halo formation and to avoid struc-ture resonances in high intensity RFQs. The detailed design aspects are studied in this paper and simulation results are given for an RFQ designed by this code, which shows the accuracy and the merits of the new program.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL051
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TUPAL061	Target and Ion Source Development for Better Beams in the ARIEL Era	ion-source, target, TRIUMF, optics	1155
	C. Babcock, T. Day Goodacre, A. Gottberg TRIUMF, Vancouver, Canada A. Gottberg Victoria University, Victoria, B.C., Canada
	Any ISOL facility pushing the boundaries of nuclear physics must be able to provide cutting-edge ion beams to its users - beams of isotopes far from stability, with few contaminants, that may be difficult to extract from an ISOL target. The development of these pure, exotic beams must be supported by continuing research and development on targets and ion sources. In the ARIEL era, new target/ion source geometries and operational modes will provide new opportunities which can only be exploited with time for development. To prioritize this, TRIUMF proposes to build a dedicated test stand for target and ion source research which will model the critical features of the new ARIEL target stations. This stand will provide a testing ground for methods of increasing efficiency and selectivity, such as investigations of new surface ion source [1,2] and FEBIAD ion source [3] designs. In addition, this will provide a development environment for new beams, either from new target materials, or through techniques such as extracting molecular beams. In order to maximize the gain from these investigations in on-line operation, the ion optical properties of the final beam will be investigated concurrently.
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TUPML077	Development of Physical Processes in Geant4 for Simulation of ISOL Target-Ion-Source System	target, simulation, proton, ion-source	1724
	P. Lee, Y.-S. Cho, J.J. Dang, H.S. Kim, H.-J. Kwon, S. Lee, Y.G. Song, S.P. Yun Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
	Funding: This work has been supported through KOMAC operation fund of KAERI and the NRF of Korea grant funded by the Korea government (MSIT) (No. NRF-2017M2A2A6A02071070). Geant4 physical processes for simulating diffusion and effusion of radioactive ions in matter have been developed for optimizing ISOL target-ion-source (TIS) system. The developed processes simulate motions of radioactive ions with sub-eV kinetic energy in the TIS geometry. The processes consist of diffusion, effusion, and radioactive decay modules, and they are designed to work seamlessly with other implemented physics lists, extending capability of the Geant4 toolkit to more complicated applications in the field of nuclear physics. The diffusion probability is analytically calculated by using the well-known Fick's formula. The effusive flow of neutral atoms is interpreted in terms of kinetic molecular theory of gases, where the interaction between atoms and the wall of a target container is described by employing Lorentz-Lambert model. By the help of newly implemented processes, it is able to simulate the release of radioactive ions from the irradiation of a proton beam on the TIS system with different geometrical parameters in a single environment. Here, we present the status of the development and plans for further improvements.
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WEPAF067	Alignment and Monitoring Systems for Accelerators and Experiments Based on BCAM - First Results and Benefits of Systems Developed for ATLAS, LHCb and HIE-ISOLDE	detector, alignment, monitoring, target	1983
	J. Gayde, B. Di Girolamo, Y. Kadi, G. Kautzmann, F. Klumb, R. Lindner, D. Mergelkuhl, L. Pontecorvo, M. Raymond, P. Sainvitu, E. Thomas CERN, Geneva, Switzerland F. Blanc, P. Stefko EPFL, Lausanne, Switzerland
	In the last few years alignment and monitoring systems based on BCAM* cameras active sensors, or their HBCAM evolution, have been developed at the request of the Technical Coordination of LHC experiments and HIE-ISOLDE facility Project Leader. ADEPO (ATLAS DEtector POsition) has been designed to speed up the precise closure - 0.3 mm - of large detector parts representing in total ~2500 tons. For LHCb a system has been studied and installed to monitor the positions of the Inner Tracker stations during the LHCb dipole magnet cycles. The MATHILDE (Monitoring and Alignment Tracking for HIE-ISOLDE) system has been developed to fulfil the alignment and monitoring needs for components of the LINAC enclosed in successive Cryo-Modules. These systems have been in each case configured and adapted to the objectives and environmental conditions: low space for integration; presence of magnetic fields; exposure to non-standard environmental conditions such as high vacuum and cryogenic temperatures. After a short description of the different systems and of the environmental constraints, this paper summarizes their first results, performances and their added value. * BCAM: Brandeis CCD Angle Monitor, http://alignment.hep.brandeis.edu/Devices/BCAM/
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF067
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WEPML021	First Performance Results of the PIP2IT MEBT 200 Ω Kicker Prototype	kicker, booster, impedance, target	2724
	G.W. Saewert, M.H. Awida, B.E. Chase, A.Z. Chen, J. Einstein-Curtis, D. Frolov, K.S. Martin, H. Pfeffer, D. Wolff Fermilab, Batavia, Illinois, USA S. Khole BARC, Trombay, Mumbai, India D. Sharma RRCAT, Indore (M.P.), India
	Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics The PIP-II project is a program to upgrade the Fermilab accelerator complex. The PIP-II linac includes a 2.1 MeV Medium Energy Beam Transport (MEBT) section that incorporates a unique chopping system to perform arbi-trary, bunch-by-bunch removal of 162.5 MHz structured beam. The MEBT chopping system will consist of two identical kickers working together and a beam absorber. One design of two having been proposed has been a 200 Ω characteristic impedance traveling wave dual-helix kicker driven with custom designed high-speed switches. This paper reports on the first performance results of one prototype kicker built, installed and tested with beam at the PIP-II Injector Test (PIP2IT) facility. The helix deflector design details are discussed. The electrical performance of the high-speed switch driver operating at 500 V bias is presented. Tests performed were chopping beam at 81.25 MHz for microseconds as well as with a truly arbitrary pattern for 550 us bursts having a 45 MHz average switching rate and repeating at 20 Hz.
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THPAL055	A Novel High Step-down DC-DC Converter with Isolated Transformer and Switched Capacitor Techniques for Corrector Magnet Bulk Power in Taiwan Photon Source	power-supply, high-voltage, simulation, operation	3769
	Y.S. Wong, K.-B. Liu NSRRC, Hsinchu, Taiwan J.F. Chen NCKU, Tainan city, Taiwan
	In this study, a high step down DC-DC converter was successfully integrated using switch capacitor and isolated transformer techniques. Switching capacitor techniques has use of capacitor parallel energy storage and series release of the way to improve the voltage conversion ratio. In addition, the output voltage ripple will be smaller due to the input current being continuous, the inductance is an element to prevent a surge current. The isolated transformer techniques has use of inductor coil turns ratio to achieve high conversion ratio. But, the leakage inductor and parasitic capacitance on the power switch will be resonant to generate a surge voltage spike when the power switch S is turned off. So that, additional a passive clamp circuit, energy of leakage inductor will be recycled to clamp capacitor and voltage stress of main power switch. The power switch S can be selected a lower Rds(on) components and reduce the conduction losses to improve power converter efficiency. Step down mode operation principle and steady-state analysis were discussed in this paper. Finally, simulation and prototype circuit is implemented in this laboratory to verify the performance, the step-down DC-DC converter is input voltage 400-V, output voltage 48-V and output power 960-W.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL055
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THPAL082	Development of a New Modular Switch Using a Next-Generation Semiconductor	power-supply, pulsed-power, timing, kicker	3841
	T. Takayanagi, K. Horino, T. Ueno JAEA/J-PARC, Tokai-mura, Japan
	An ultra-high-speed short pulse switch for high power have been developed by using SIC - MOSFET which is one of next generation semiconductors. Semiconductor switches using SIC-MOSFETs are expected to replace the thyratron, and they are composed of circuits in which many semiconductor switches are multiplexed in series and parallel for high power. Semiconductor switches using SIC-MOSFETs are expected to replace the thyratron, and they are also designed by connecting many semiconductor switches in parallel-series. To realize a low switching noise, it is common to form a symmetrical circuit. However, as the number of parallel connections increases, the circuit length between input and output becomes longer, so the output waveform is distorted due to any timing jitter or level fluctuation. Therefore, we propose a radially symmetric type of a module switch which does not cause level fluctuation due to the timing jitter by equalizing the circuit length independently of the number of semiconductor switches. The design and preliminary test results of two types of switch circuits, radially symmetric type and line symmetric type are presented here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL082
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THPAL108	In-Situ Characterization of Normal Conducting RF Cavities in Solaris Light Source Storage Ring	cavity, HOM, storage-ring, simulation	3891
	P.B. Borowiec, A.I. Wawrzyniak Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland J. Björklund Svensson Lund University, Division of Atomic Physics, Lund, Sweden
	The SOLARIS 1.5 GeV storage ring is equipped with two 100 MHz active cavities and two 3rd harmonic passive cavities. They are in operation since 2015. For control of their respective working points, knowledge about cavity voltage and higher order mode (HOM) frequency spec-trum is mandatory. After their installation in the storage ring and connection of the RF feeder to a high power isolator and a transmitter, the influence of the external elements on the quality factor and the HOM spectrum should be verified with respect to simulations of a simpli-fied model of a stand-alone cavity. This paper will pre-sent results of in-situ cavity measurements to qualify the HOM placement and their quality factor. HOM meas-urements have been performed in the range 100 MHz to 1.3 GHz for active cavities and 300 MHz to 1.5 GHz for 3rd harmonic cavities at three different temperatures under ultra-high vacuum conditions for each cavity separately. The measurement and analysis methodology will also be presented
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL108
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THPMF046	Precision Charge Measurement of 40~MeV Electron-Beam to Calibrate Air Fluorescence Telescope for Cosmic Ray Observation	electron, vacuum, ECR, injection	4163
	T. Shibata KEK, Ibaraki, Japan O.C. Shin OCU, Osaka, Japan
	The Telescope Array (TA) is ultra-high energy cosmic ray observation (UHECR). TA is using the fluorescence detectors (FD) for observation the air fluorescence(AFY) which are emitted in the cascade generated by an UHECR in atmosphere. One of the important observables is primary energy of UHECR, however it has 21% systematic uncertainty. For reduction of the uncertainty, we have been operated an 40-MeV electron linear accelerator from 2010 which we have constructed for absolute energy calibration. The accelerator is located at 100 m from FD station, and can shot electron beam which the direction is vertical into the air, the energy is 40-MeV, the pulse width is 1 micro-second, and the beam charge is 160 pC. The AFY efficiency and FD calibration parameters can be calibrated, which means energy scale of UHECR, by observation of the AFY which are generated by the electron beam in the air. The most important beam parameter is beam charge. The requirement of the accuracy of charge measurement is a few %, then we have developed the double faraday cups and one current transfer system. We calibrated the current transfer by the double faraday cups, and we could achieve about 1% accuracy.
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THPMK035	Generation of Isolated Zeptosecond Pulse in Gamma-Ray Free Electron Laser	undulator, radiation, electron, laser	4375
	C.H. Shim, D.E. Kim POSTECH, Pohang, Kyungbuk, Republic of Korea Y.W. Parc PAL, Pohang, Kyungbuk, Republic of Korea
	An X-ray pulse with zeptosecond pulse duration is an essential tool to resolve the nuclear dynamics. To make such a short pulse duration, we need to make a very wide frequency range radiation which is known from the uncertainty principle. The spectral range of an isolated zeptosecond pulse has to be of order of few keV which is called as a gamma ray. In this presentation, the generation of an isolated zeptosecond pulses in the gamma-ray free electron laser is studied by the simulation.
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THPMK094	Thermal Design of a 100 kW Electron to Gamma Converter at TRIUMF	electron, target, TRIUMF, experiment	4520
	B.G. Cade, L. Egoriti, A. Gottberg TRIUMF, Vancouver, Canada D.R. Priessl UVIC, Victoria, Canada
	The electron target station (AETE) of the TRIUMF-ARIEL Facility will employ an electron "driver" beam to irradiate Isotope Separator On-Line (ISOL) targets for the production of radioactive isotopes via photofission. 30 MeV electrons will be converted to gamma spectrum Bremsstrahlung photons via an electron to gamma (e-y) converter located upstream of the ISOL target. The e-y concept uses a composite metal with two layers: One high-Z material to convert electrons to photons, and one low-Z material to provide structural support, thermal dissipation, and maximal transparency to the produced gamma photons. Several material combinations and bonding processes are currently being evaluated and tested using TRIUMF's E-LINAC. Water-cooling and thermal design are being optimized for 100 kW operation and have thus far been validated up to 10 kW driver beam power. The latest test results and future prospects are summarized.
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THPML047	Design and Measurement of the X-Band Pulse Compressor for TTX	cavity, GUI, coupling, vacuum	4745
	Y.L. Jiang, H.B. Chen, C. Cheng, W. Gai, J. Shi, P. Wang, Z.H. Wang, X.W. Wu, H. Zha TUB, Beijing, People's Republic of China
	A radio frequency (RF) pulse compressor had been designed for the X-band (11.424 GHz) high power test stands at the Accelerator Laboratory of Tsinghua University. It is the SLED-I type pulse compressor, which uses a high quality factor corrugated circular cavity to store the RF power. An RF polarizer couples two quadrature modes into the cavity so that the pulse compressor needs only one cavity. The cavity implements HE1-1-14 mode, with the Q0 of 115, 000 and the coupling factor (β) of 3.23. The design and the microwave measurement before brazing of this pulse compressor are presented in this paper.
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THPML131	A NEW PRODUCTION PROCESS FOR UCx TARGETS FOR RADIOACTIVE ISOTOPE BEAMS AT TRIUMF	vacuum, target, TRIUMF, ISAC	4990
	M. S. Cervantes, P. Fouquet-Métivier, A. Gottberg, P. Kunz, L. Lambert, A. Mjøs, J. Wong TRIUMF, Vancouver, Canada M. S. Cervantes UVIC, Victoria, Canada P. Fouquet-Métivier ENSCM, Montpellier, France A. Gottberg Victoria University, Victoria, B.C., Canada
	TRIUMF has the objective of producing radioactive isotope beams (RIB) using the ISOL method. Radioactive isotopes are used in experiments in different areas of science. At the TRIUMF-ISAC facility, a 500 MeV proton driver beam impinges onto different targets and induces nuclear reactions in them. The isotopes obtained in this way then diffuse out of the target material before they are ionized and extracted to form an isotope beam. Targets of uranium carbide with excess of graphite (UCx) are the most requested targets at TRIUMF. ARIEL, TRIUMF's flagship project, aims at increasing the radioactive isotope production capabilities to satisfy the growing demand of radioactive isotopes. The current production method of UCx targest does not have the means to supply enough UCx targets to satisfy ARIEL's demand, therefore, a new method for efficient UCx target material synthesis is being developed.
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Paper

Title

Other Keywords

Page

MOPMF043

Tuning of CLIC-Final Focus System 3 TeV Baseline Design Under Static and Dynamic Imperfections

luminosity, collider, linear-collider, simulation

196

E. Marín, A. Latina, J. Pfingstner, D. Schulte, R. Tomás
CERN, Geneva, Switzerland
J. Pfingstner
University of Oslo, Oslo, Norway

In this paper we present the tuning study of the Compact Linear Collider - Final Focus System (CLIC-FFS) 3~TeV baseline design under static and dynamic imperfections for the first time. The motion of the FFS magnets due to ground motion and the impact of active and passive mechanisms envisaged to stabilize both e^- and e⁺ systems are described. It is found that the Pre-isolator required for stabilization of the Final Doublet drives the performance of the collider at the final stages of the tuning process. The obtained tuning performance depending on the stabilization techniques are discussed in detail.

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TUPAF041

Residual Gas Ions Characterization from the REXEBIS

detector, rfq, experiment, electron

784

N. Bidault, M.L. Lozano, J.A. Rodriguez
CERN, Geneva, Switzerland

The Isotope mass Separator On-Line DEvice (ISOLDE) is a user facility located at CERN where Radioactive Ion Beams (RIBs) are produced from proton collisions onto a target, mass separated and transported to user experimental stations either directly at low energy or after being post- accelerated, notably for nuclear physics studies. Prior to acceleration through the REX/HIE-ISOLDE linear acceler- ator, the ion beam is accumulated, bunched and cooled in a Penning trap (REXTRAP) and afterwards charge-bred in an Electron Beam Ion Source (REXEBIS). Multi-charged radioactive species of interest are then selected by a mass-to- charge (A/q) ratio separator dipole in the Low Energy Beam Transfer Line (LEBT). A method is presented to character- ize the Residual Gas Ion (RGI) background contamination for diﬀerent operational conditions of the REXEBIS. More particularly, a discussion is held about the inﬂuence of the conﬁnement time inside the charge-breeder on the residual gas spectrum. Finally, a method to identify sub-pico-Ampere contaminants is demonstrated.

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TUPAF042

Characterization of the Beam Energy Spread at the REX/HIE-ISOLDE Linac

cavity, linac, experiment, detector

787

M.L. Lozano, N. Bidault, E. Fadakis, M.A. Fraser, E. Matli, J.A. Rodriguez
CERN, Geneva, Switzerland

ISOLDE is an on-line radioactive isotope separator located at CERN that works by colliding protons accelerated in the PS Booster into a fixed target and by separating the resultant ionized isotopes using a magnetic separator. The completion of the HIE-ISOLDE superconducting linac allows the acceleration of these ions to energy levels that were not reachable before, opening the door to new experiments in different fields. These experiments often have special requirements in terms of beam intensity and purity, transverse emittance or energy spread. A possible way to reduce the energy spread of the beam delivered to the experimental stations is to use one or more of the superconducting cavities as bunchers. The main results of several tests conducted during the last beam commissioning campaign prove that this mode of operation is feasible and will be presented in this paper.

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TUPAL051

Program for High-Intensity RFQ Design With Matched and Equipartitioned Design Strategy

rfq, emittance, linac, resonance

1126

H.P. Li, M.J. Easton, Q. Fu, P.P. Gan, Y.R. Lu, Q.Y. Tan, Z. Wang, K. Zhu
PKU, Beijing, People's Republic of China

The deuteron driver accelerator of the Beijing Iso-tope Separation On-Line (BISOL) facility will acceler-ate and deliver a 20 mA deuteron beam to the targets with an energy of 40 MeV. As the injector of the driver linac, an RFQ is required to bunch and accelerate the 20 mA deuteron beam to 3 MeV with very high beam quality. In order to fulfil these requirements and re-duce time spent on optimization, an RFQ design pro-gram named RFQEP has been developed to generate the input file for the PARMTEQM code. In this program, the ‘matched and equipartitioned' design strategy is adopted to prevent halo formation and to avoid struc-ture resonances in high intensity RFQs. The detailed design aspects are studied in this paper and simulation results are given for an RFQ designed by this code, which shows the accuracy and the merits of the new program.

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TUPAL061

Target and Ion Source Development for Better Beams in the ARIEL Era

ion-source, target, TRIUMF, optics

1155

C. Babcock, T. Day Goodacre, A. Gottberg
TRIUMF, Vancouver, Canada
A. Gottberg
Victoria University, Victoria, B.C., Canada

Any ISOL facility pushing the boundaries of nuclear physics must be able to provide cutting-edge ion beams to its users - beams of isotopes far from stability, with few contaminants, that may be difficult to extract from an ISOL target. The development of these pure, exotic beams must be supported by continuing research and development on targets and ion sources. In the ARIEL era, new target/ion source geometries and operational modes will provide new opportunities which can only be exploited with time for development. To prioritize this, TRIUMF proposes to build a dedicated test stand for target and ion source research which will model the critical features of the new ARIEL target stations. This stand will provide a testing ground for methods of increasing efficiency and selectivity, such as investigations of new surface ion source [1,2] and FEBIAD ion source [3] designs. In addition, this will provide a development environment for new beams, either from new target materials, or through techniques such as extracting molecular beams. In order to maximize the gain from these investigations in on-line operation, the ion optical properties of the final beam will be investigated concurrently.

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TUPML077

Development of Physical Processes in Geant4 for Simulation of ISOL Target-Ion-Source System

target, simulation, proton, ion-source

1724

P. Lee, Y.-S. Cho, J.J. Dang, H.S. Kim, H.-J. Kwon, S. Lee, Y.G. Song, S.P. Yun
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea

Funding: This work has been supported through KOMAC operation fund of KAERI and the NRF of Korea grant funded by the Korea government (MSIT) (No. NRF-2017M2A2A6A02071070).
Geant4 physical processes for simulating diffusion and effusion of radioactive ions in matter have been developed for optimizing ISOL target-ion-source (TIS) system. The developed processes simulate motions of radioactive ions with sub-eV kinetic energy in the TIS geometry. The processes consist of diffusion, effusion, and radioactive decay modules, and they are designed to work seamlessly with other implemented physics lists, extending capability of the Geant4 toolkit to more complicated applications in the field of nuclear physics. The diffusion probability is analytically calculated by using the well-known Fick's formula. The effusive flow of neutral atoms is interpreted in terms of kinetic molecular theory of gases, where the interaction between atoms and the wall of a target container is described by employing Lorentz-Lambert model. By the help of newly implemented processes, it is able to simulate the release of radioactive ions from the irradiation of a proton beam on the TIS system with different geometrical parameters in a single environment. Here, we present the status of the development and plans for further improvements.

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WEPAF067

Alignment and Monitoring Systems for Accelerators and Experiments Based on BCAM - First Results and Benefits of Systems Developed for ATLAS, LHCb and HIE-ISOLDE

detector, alignment, monitoring, target

1983

J. Gayde, B. Di Girolamo, Y. Kadi, G. Kautzmann, F. Klumb, R. Lindner, D. Mergelkuhl, L. Pontecorvo, M. Raymond, P. Sainvitu, E. Thomas
CERN, Geneva, Switzerland
F. Blanc, P. Stefko
EPFL, Lausanne, Switzerland

In the last few years alignment and monitoring systems based on BCAM* cameras active sensors, or their HBCAM evolution, have been developed at the request of the Technical Coordination of LHC experiments and HIE-ISOLDE facility Project Leader. ADEPO (ATLAS DEtector POsition) has been designed to speed up the precise closure - 0.3 mm - of large detector parts representing in total ~2500 tons. For LHCb a system has been studied and installed to monitor the positions of the Inner Tracker stations during the LHCb dipole magnet cycles. The MATHILDE (Monitoring and Alignment Tracking for HIE-ISOLDE) system has been developed to fulfil the alignment and monitoring needs for components of the LINAC enclosed in successive Cryo-Modules. These systems have been in each case configured and adapted to the objectives and environmental conditions: low space for integration; presence of magnetic fields; exposure to non-standard environmental conditions such as high vacuum and cryogenic temperatures. After a short description of the different systems and of the environmental constraints, this paper summarizes their first results, performances and their added value.
* BCAM: Brandeis CCD Angle Monitor, http://alignment.hep.brandeis.edu/Devices/BCAM/

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WEPML021

First Performance Results of the PIP2IT MEBT 200 Ω Kicker Prototype

kicker, booster, impedance, target

2724

G.W. Saewert, M.H. Awida, B.E. Chase, A.Z. Chen, J. Einstein-Curtis, D. Frolov, K.S. Martin, H. Pfeffer, D. Wolff
Fermilab, Batavia, Illinois, USA
S. Khole
BARC, Trombay, Mumbai, India
D. Sharma
RRCAT, Indore (M.P.), India

Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics
The PIP-II project is a program to upgrade the Fermilab accelerator complex. The PIP-II linac includes a 2.1 MeV Medium Energy Beam Transport (MEBT) section that incorporates a unique chopping system to perform arbi-trary, bunch-by-bunch removal of 162.5 MHz structured beam. The MEBT chopping system will consist of two identical kickers working together and a beam absorber. One design of two having been proposed has been a 200 Ω characteristic impedance traveling wave dual-helix kicker driven with custom designed high-speed switches. This paper reports on the first performance results of one prototype kicker built, installed and tested with beam at the PIP-II Injector Test (PIP2IT) facility. The helix deflector design details are discussed. The electrical performance of the high-speed switch driver operating at 500 V bias is presented. Tests performed were chopping beam at 81.25 MHz for microseconds as well as with a truly arbitrary pattern for 550 us bursts having a 45 MHz average switching rate and repeating at 20 Hz.

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THPAL055

A Novel High Step-down DC-DC Converter with Isolated Transformer and Switched Capacitor Techniques for Corrector Magnet Bulk Power in Taiwan Photon Source

power-supply, high-voltage, simulation, operation

3769

Y.S. Wong, K.-B. Liu
NSRRC, Hsinchu, Taiwan
J.F. Chen
NCKU, Tainan city, Taiwan

In this study, a high step down DC-DC converter was successfully integrated using switch capacitor and isolated transformer techniques. Switching capacitor techniques has use of capacitor parallel energy storage and series release of the way to improve the voltage conversion ratio. In addition, the output voltage ripple will be smaller due to the input current being continuous, the inductance is an element to prevent a surge current. The isolated transformer techniques has use of inductor coil turns ratio to achieve high conversion ratio. But, the leakage inductor and parasitic capacitance on the power switch will be resonant to generate a surge voltage spike when the power switch S is turned off. So that, additional a passive clamp circuit, energy of leakage inductor will be recycled to clamp capacitor and voltage stress of main power switch. The power switch S can be selected a lower Rds(on) components and reduce the conduction losses to improve power converter efficiency. Step down mode operation principle and steady-state analysis were discussed in this paper. Finally, simulation and prototype circuit is implemented in this laboratory to verify the performance, the step-down DC-DC converter is input voltage 400-V, output voltage 48-V and output power 960-W.

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THPAL082

Development of a New Modular Switch Using a Next-Generation Semiconductor

power-supply, pulsed-power, timing, kicker

3841

T. Takayanagi, K. Horino, T. Ueno
JAEA/J-PARC, Tokai-mura, Japan

An ultra-high-speed short pulse switch for high power have been developed by using SIC - MOSFET which is one of next generation semiconductors. Semiconductor switches using SIC-MOSFETs are expected to replace the thyratron, and they are composed of circuits in which many semiconductor switches are multiplexed in series and parallel for high power. Semiconductor switches using SIC-MOSFETs are expected to replace the thyratron, and they are also designed by connecting many semiconductor switches in parallel-series. To realize a low switching noise, it is common to form a symmetrical circuit. However, as the number of parallel connections increases, the circuit length between input and output becomes longer, so the output waveform is distorted due to any timing jitter or level fluctuation. Therefore, we propose a radially symmetric type of a module switch which does not cause level fluctuation due to the timing jitter by equalizing the circuit length independently of the number of semiconductor switches. The design and preliminary test results of two types of switch circuits, radially symmetric type and line symmetric type are presented here.

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THPAL108

In-Situ Characterization of Normal Conducting RF Cavities in Solaris Light Source Storage Ring

cavity, HOM, storage-ring, simulation

3891

P.B. Borowiec, A.I. Wawrzyniak
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
J. Björklund Svensson
Lund University, Division of Atomic Physics, Lund, Sweden

The SOLARIS 1.5 GeV storage ring is equipped with two 100 MHz active cavities and two 3rd harmonic passive cavities. They are in operation since 2015. For control of their respective working points, knowledge about cavity voltage and higher order mode (HOM) frequency spec-trum is mandatory. After their installation in the storage ring and connection of the RF feeder to a high power isolator and a transmitter, the influence of the external elements on the quality factor and the HOM spectrum should be verified with respect to simulations of a simpli-fied model of a stand-alone cavity. This paper will pre-sent results of in-situ cavity measurements to qualify the HOM placement and their quality factor. HOM meas-urements have been performed in the range 100 MHz to 1.3 GHz for active cavities and 300 MHz to 1.5 GHz for 3rd harmonic cavities at three different temperatures under ultra-high vacuum conditions for each cavity separately. The measurement and analysis methodology will also be presented

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THPMF046

Precision Charge Measurement of 40~MeV Electron-Beam to Calibrate Air Fluorescence Telescope for Cosmic Ray Observation

electron, vacuum, ECR, injection

4163

T. Shibata
KEK, Ibaraki, Japan
O.C. Shin
OCU, Osaka, Japan

The Telescope Array (TA) is ultra-high energy cosmic ray observation (UHECR). TA is using the fluorescence detectors (FD) for observation the air fluorescence(AFY) which are emitted in the cascade generated by an UHECR in atmosphere. One of the important observables is primary energy of UHECR, however it has 21% systematic uncertainty. For reduction of the uncertainty, we have been operated an 40-MeV electron linear accelerator from 2010 which we have constructed for absolute energy calibration. The accelerator is located at 100 m from FD station, and can shot electron beam which the direction is vertical into the air, the energy is 40-MeV, the pulse width is 1 micro-second, and the beam charge is 160 pC. The AFY efficiency and FD calibration parameters can be calibrated, which means energy scale of UHECR, by observation of the AFY which are generated by the electron beam in the air. The most important beam parameter is beam charge. The requirement of the accuracy of charge measurement is a few %, then we have developed the double faraday cups and one current transfer system. We calibrated the current transfer by the double faraday cups, and we could achieve about 1% accuracy.

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THPMK035

Generation of Isolated Zeptosecond Pulse in Gamma-Ray Free Electron Laser

undulator, radiation, electron, laser

4375

C.H. Shim, D.E. Kim
POSTECH, Pohang, Kyungbuk, Republic of Korea
Y.W. Parc
PAL, Pohang, Kyungbuk, Republic of Korea

An X-ray pulse with zeptosecond pulse duration is an essential tool to resolve the nuclear dynamics. To make such a short pulse duration, we need to make a very wide frequency range radiation which is known from the uncertainty principle. The spectral range of an isolated zeptosecond pulse has to be of order of few keV which is called as a gamma ray. In this presentation, the generation of an isolated zeptosecond pulses in the gamma-ray free electron laser is studied by the simulation.

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THPMK094

Thermal Design of a 100 kW Electron to Gamma Converter at TRIUMF

electron, target, TRIUMF, experiment

4520

B.G. Cade, L. Egoriti, A. Gottberg
TRIUMF, Vancouver, Canada
D.R. Priessl
UVIC, Victoria, Canada

The electron target station (AETE) of the TRIUMF-ARIEL Facility will employ an electron "driver" beam to irradiate Isotope Separator On-Line (ISOL) targets for the production of radioactive isotopes via photofission. 30 MeV electrons will be converted to gamma spectrum Bremsstrahlung photons via an electron to gamma (e-y) converter located upstream of the ISOL target. The e-y concept uses a composite metal with two layers: One high-Z material to convert electrons to photons, and one low-Z material to provide structural support, thermal dissipation, and maximal transparency to the produced gamma photons. Several material combinations and bonding processes are currently being evaluated and tested using TRIUMF's E-LINAC. Water-cooling and thermal design are being optimized for 100 kW operation and have thus far been validated up to 10 kW driver beam power. The latest test results and future prospects are summarized.

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THPML047

Design and Measurement of the X-Band Pulse Compressor for TTX

cavity, GUI, coupling, vacuum

4745

Y.L. Jiang, H.B. Chen, C. Cheng, W. Gai, J. Shi, P. Wang, Z.H. Wang, X.W. Wu, H. Zha
TUB, Beijing, People's Republic of China

A radio frequency (RF) pulse compressor had been designed for the X-band (11.424 GHz) high power test stands at the Accelerator Laboratory of Tsinghua University. It is the SLED-I type pulse compressor, which uses a high quality factor corrugated circular cavity to store the RF power. An RF polarizer couples two quadrature modes into the cavity so that the pulse compressor needs only one cavity. The cavity implements HE1-1-14 mode, with the Q0 of 115, 000 and the coupling factor (β) of 3.23. The design and the microwave measurement before brazing of this pulse compressor are presented in this paper.

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THPML131

A NEW PRODUCTION PROCESS FOR UCx TARGETS FOR RADIOACTIVE ISOTOPE BEAMS AT TRIUMF

vacuum, target, TRIUMF, ISAC

4990

M. S. Cervantes, P. Fouquet-Métivier, A. Gottberg, P. Kunz, L. Lambert, A. Mjøs, J. Wong
TRIUMF, Vancouver, Canada
M. S. Cervantes
UVIC, Victoria, Canada
P. Fouquet-Métivier
ENSCM, Montpellier, France
A. Gottberg
Victoria University, Victoria, B.C., Canada

TRIUMF has the objective of producing radioactive isotope beams (RIB) using the ISOL method. Radioactive isotopes are used in experiments in different areas of science. At the TRIUMF-ISAC facility, a 500 MeV proton driver beam impinges onto different targets and induces nuclear reactions in them. The isotopes obtained in this way then diffuse out of the target material before they are ionized and extracted to form an isotope beam. Targets of uranium carbide with excess of graphite (UCx) are the most requested targets at TRIUMF. ARIEL, TRIUMF's flagship project, aims at increasing the radioactive isotope production capabilities to satisfy the growing demand of radioactive isotopes. The current production method of UCx targest does not have the means to supply enough UCx targets to satisfy ARIEL's demand, therefore, a new method for efficient UCx target material synthesis is being developed.

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