Paper | Title | Page |
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MOPO085 | Prototype of an Inter-digital H-mode Drift-tube Linac for Muon Linac | 180 |
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An inter-digital H-mode (IH) drift-tube linac (DTL) is developed for a low velocity part in a muon linac at the J-PARC E34 experiment. It will accelerate muons from v/c = 0.08 to 0.28 at an operational frequency of 324 MHz. In order to achieve higher acceleration efficiency and make cost lower, an alternative phase focusing (APF) scheme is adopted. A prototype with 6 cells of 0.45 m length was manufactured. The prototype accelerates muons from v/c = 0.08 to 0.15 stage. We conducted frequency measurement and bead-pull measurement as a low-power measurement, in order to evaluate the prototype product. In this paper, the results of the low-power measurement for prototype cavity will be presented. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO085 | |
About • | paper received ※ 10 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019 | |
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TUPO010 | Muon Acceleration Test with the RFQ Towards the Development of the Muon Linac | 342 |
SPWR015 | use link to see paper's listing under its alternate paper code | |
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The muon linac to accelerate muons 212 MeV is planned in order to measure the muon dipole moments precisely in the J-PARC. The muon acceleration with a RF accelerator hasn’t been demonstrated yet in the world. Therefore the muon acceleration test with the RFQ as the feasibility test of the muon linac was demonstrated at the Muon D line in the J-PARC MLF. Conventional muons are cooled with producing ultra-slow muons using the muonium production and the ionization laser for the muon linac. However these apparatuses couldn’t be used because of the limitation of the experimental area in the acceleration test. Therefore the conventional muon was converted to the negative muonium ion (Mu-) with less than 2 keV using the thin aluminum foil target as the easy cooling method. The Mu- was finally accelerated to 90 keV using the RFQ. The accelerated Mu- was selected with a diagnostic beam line and identified with the Time-Of-Flight measurement using a MCP detector. The result of the world’s first muon acceleration test with the RFQ will be reported in this presentation. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO010 | |
About • | paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019 | |
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THPO048 | Low Power Measurement of a 1300-MHz RFQ Cold Model | 794 |
THOP02 | use link to see paper's listing under its alternate paper code | |
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Funding: This work is supported by JSPS KAKENHI Grant Number 17K18784. A muon linac development for a new muon g-2/EDM experiment is now going on at J-PARC. Muons from the muon beam line (H-line) of the J-PARC muon facility are once stopped in a silica aerojel target and room temperature muoniums are evaporated from the aerogel. They are dissociated with the lasers to be the ultra slow muons, then accelerated up to 212 MeV using a linear accelerator. The low energy part of this muon linac consists of a 324-MHz RFQ and an IH DTL. The frequency is increased to 1296 MHz at the following CCL section. We propose to replace the low energy section to a 1300-MHz RFQ to simplify the configuration of the muon linac. The 1300-MHz RFQ will be extremely small compared to conventional RFQs, therefore we made a cold model to proof the feasibility of this scheme. In this paper, the result of low-power measurement of the 1300-MHz RFQ cold model is described. |
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Slides THPO048 [2.160 MB] | |
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO048 | |
About • | paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019 | |
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THPO049 | Field Tuning of a Radio-frequency Quadrupole Using Full 3D Modeling | 798 |
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The radio-frequency quadrupole linac (RFQ) is operating in the frontend of the J-PARC linac to accelerates 50 mA negative hydrogen beams from 0.05 MeV to 3 MeV. As a backup, the spare RFQ has been fabricated in 2018. The vane-voltage ramping is adopted to improve the acceleration efficiency so that the cross-sectional shape is adjusted longitudinally to produce the designed voltage distribution. Then, the three-dimensional cavity models including modulations and cutbacks were created in CST Micro-Wave Studio. The vane-base widths and cutback depths were optimized to produce the desired vane-voltage distribution. In the final tuning, the heights of the stub turners were also determined based on the tuner responses obtained from the full 3D models. In this paper, the detailed design process of the cavity dimensions and the result of the low-power measurements are described. | ||
DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO049 | |
About • | paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019 | |
Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |