| Paper | Title | Page |
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| TUPAK008 | Longitudinal Bunch Size Measurements with an RF Deflector at J-PARC LINAC | 974 |
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| Measurement of the longitudinal bunch size is important for the stable beam operation. Especially in a medium energy beam transport (MEBT) located after a radio-frequency quadrupole in J-PARC, it is necessary to measure the bunch size with minimum set of equipment to avoid subsequent emittance growth due to space charge. We had proposed a longitudinal size measurement with an rf deflector normally used for deflecting theμbunch; phase spread is migrated to spatial one if the reference particle arrives at the deflector when the voltage is rising in time and is zero. Then a buncher cavity located upstream of the deflector is utilized to scan the phase spread to measure the longitudinal beam parameters. In this poster, recent measurement results are presented. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK008 | |
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| TUPAL076 | Result of the First Muon Acceleration with Radio Frequency Quadrupole | 1190 |
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Funding: This work is supported by JSPS KAKENHI Grant Numbers JP15H03666, JP16H03987, and JP16J07784. J-PARC E34 experiment aims to measure the muon g-2/EDM precisely with novel techniques including the muon linear accelerator. Slow muon source by the metal foil method in order to cool the muon beam has been developed for the muon acceleration test with RF accelerator, because the muon beam derived from the proton driver was the tertiary beam and has a large emittance. The first verification test of the muon acceleration with RFQ was carried out at the muon test beam line of J-PARC MLF in October 2017. The incident surface muons were decelerated by the thin metal foil target and produced the negative muonium ions (Mu-), which is the bound stat of a positive muon and two electrons. After Mu- were extracted by a electrostatic accelerator as the injector of the RFQ, they were accelerated with RFQ to 88.6 keV. The accelerated Mu- were identified by the momentum selection with the bending magnet after the RFQ, and the measurement of the Time-Of-Flight. Accelerated Mu- were easily distinguished from penetrated positive muons by the difference of the polarity. The latest analysis result of the world's first muon acceleration with RFQ will be reported in this paper. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAL076 | |
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| WEPAL016 | Tensile Fracture Test of Metallic Wire of Beam Profile Monitors | 2183 |
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| In order to mitigate the beam loss during a beam transportation in a high-brilliant accelerator facilities, wire-based profile monitors are used to measure by both transverse and longitudinal beam profiles using wire-scanner monitors (WSMs) and bunch-shape monitors (BSMs) for the tuning of quadrupole magnets and bunching cavities. Signals are come from the direct interaction between a metallic wire and beam. We have used the tungsten wire as a high melting-point material by estimation of heat loading during the impact of beam particles. In addition, a spring is applied for the relaxing a sag under wire's own weight. A tensile fracture test is conducted by supplying an electrical current as a simulated beam-heat loading. As the results, we obtained the relation between the thermal limit to break down and tension loading of tungsten wire. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL016 | |
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| WEPAL017 | Adaptive Feedforward Control Design Based on Simulink for the J-PARC LINAC LLRF System | 2187 |
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| In j-parc linac, for dealing with high beam loading effect, an adaptive feedforward control method which based on iterative learning control was put forward. At the same time, in order to verify its effectiveness before it is officially put into use, an llrf system simulation model was built in simulink, matlab. In this paper, the architecture of llrf system simulation model will be introduced. The result of iterative learning control (ILC) is summarized. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL017 | |
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| WEPAL021 | Study of a Tuner for a High-Accuracy Bunch Shape Monitor | 2200 |
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| In the J-PARC Linac, development and higher precision of Bunch Shape Monitor (BSM) have been progressed for measuring the longitudinal beam distribution. To transform a longitudinal beam-profile into transverse one with an rf field, we need the field having an acceleration synchronizing frequency. An rf deflector of BSM consists of a half λ cylindrical cavity and two electrodes for deflection. In general, the resonance frequency can be tuned by adjusting the electrode length. We designed the new tuner with CST Studio. We can control the resonance frequency by Adjusting not only the electrode length but the cavity volume. We found the optimum lengths of electrode and volume for tuning. We introduce development of the new rf tuner for BSM in this paper. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL021 | |
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