Simulation of longitudinal beam manipulation during multi-turn injection in J-PARC RCS

Yamamoto, Masanobu; Nomura, Masahiro; Schnase, A.; Shimada, Taihei; Suzuki, Hiromitsu; Tamura, Fumihiko; Ezura, E.; Hara, K.; Hasegawa, K.; Ohmori, C.; Takata, K.; Takagi, A.; Toda, Makoto; Yoshii, M.

doi:10.1016/j.nima.2010.04.050

Cited by 27 publications

(15 citation statements)

References 5 publications

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“…Longitudinal injection painting [16,17] makes use of a controlled momentum offset to the rf bucket in combination with superposing a second harmonic rf to obtain a uniform longitudinal particle distribution after the multiturn injection. Figure 6 shows a schematic diagram of the momentum offset injection.…”

Section: Longitudinal Injection Paintingmentioning

confidence: 99%

“…That is, in anticorrelated painting, the injection beam is filled from the middle to the outside on the horizontal plane, while it is painted from the outside to the middle on the vertical plane, as per the combination of Eqs. (6) and (17). Figure 35 shows the transverse phase space coordinates and the tune footprints at 0.16 ms (the first one-third of injection) and 0.5 ms (the end of injection) calculated for the beam intensity of 1 MW with correlated and anticorrelated painting of ϵ tp ¼ 200π mm mrad.…”

Section: Anticorrelated Painting Vs Correlated Paintingmentioning

confidence: 99%

See 1 more Smart Citation

Achievement of a low-loss 1-MW beam operation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

Hotchi

Harada

Hayashi

et al. 2017

Phys. Rev. Accel. Beams

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The 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) is now in the final beam commissioning phase, aiming for a design output beam power of 1 MW. With a series of injector linac upgrades in 2013 and 2014, RCS developed a high-intensity beam test, and launched 1-MW beam tuning in October 2014. The most important issues in realizing such a high-power continuous beam operation are to control and minimize beam loss for maintaining machine activations within permissible levels. In RCS, numerical simulation was successfully utilized along with experimental approaches to isolate the mechanism of beam loss and find its solution. By iteratively performing actual beam experiments and numerical simulations, and also by several hardware improvements, we have recently established a 1-MW beam operation with very low fractional beam loss of a couple of 10 −3 . In this paper, our recent efforts toward realizing such a low-loss high-intensity beam acceleration are presented as a follow-up of our previous article, H. Hotchi et al. Phys. Rev. ST Accel. Beams 12, 040402 (2009), in which the initial beam commissioning status of RCS has been reported.

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Section: Longitudinal Injection Paintingmentioning

confidence: 99%

Section: Anticorrelated Painting Vs Correlated Paintingmentioning

confidence: 99%

Achievement of a low-loss 1-MW beam operation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

Hotchi

Harada

Hayashi

et al. 2017

Phys. Rev. Accel. Beams

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“…For improving the longitudinal beam distribution, the longitudinal motion was thoroughly surveyed for various combinations of rf parameters, especially V 2 =V 1 , 2 , and the momentum offset Áp=p, in both numerical simulations [14] and experiments [15]. In the present beam tuning experiment, the second harmonic rf voltage was employed typically with an amplitude of 80% of the fundamental one during the first 1 ms, decreasing to 0 kV in the next 2 ms, as shown in Fig.…”

Section: B Longitudinal Phase-space Paintingmentioning

confidence: 99%

“…By combining such a dynamically controlled rf bucket potential and the momentum offset injection of À0:2% with the corresponding rf frequency offset, we obtained a well uniformly shaped longitudinal beam distribution, as is described in the following section (further details of the rf parameter dependence on the longitudinal motion are described in Refs. [14,15]). …”

Section: B Longitudinal Phase-space Paintingmentioning

confidence: 99%

Beam loss reduction by injection painting in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

Hotchi

Harada

Hayashi

et al. 2012

Phys. Rev. ST Accel. Beams

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The 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex was commissioned in October 2007. Via the initial beam tuning and a series of underlying beam studies with low-intensity beams, since December 2009, we have intermittently been performing beam tuning experiments with higher-intensity beams including the injection painting technique. By optimizing the injection painting parameters, we have successfully achieved a 420 kW-equivalent output intensity at a low-level intensity loss of less than 1%. Also the corresponding numerical simulation well reproduced the observed painting parameter dependence on the beam loss, and captured a characteristic behavior of the high-intensity beam in the injection painting process. In this paper, we present the experimental results obtained in the course of the RCS beam power ramp-up, especially on the beam loss reduction achieved by employing the injection painting, together with the numerical simulation results.

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“…As the RCS needs a wide bandwidth for acceleration from low energy (181 MeV), and it also needs a dual harmonic rf [9][10][11], the Q value of the RCS cavity is about 2, defined by an external inductor [12]. In the MR, the frequency variation is only 3% and a higher Q value is preferred because of the heavy beam loading.…”

Section: Introductionmentioning

confidence: 99%

Development of a high gradient rf system using a nanocrystalline soft magnetic alloy

Ohmori

Ezura

Hara

et al. 2013

Phys. Rev. ST Accel. Beams

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The future high intensity upgrade project of the J-PARC (Japan Proton Accelerator Research Complex) MR (Main Ring) includes developments of high gradient rf cavities and magnet power supplies for high repetition rate. The scenario describing the cavity replacements is reported. By the replacement plan, the total acceleration voltage will be almost doubled, while the number of rf stations remains the same. The key issue is the development of a high gradient rf system using high impedance magnetic alloy, FT3L. The FT3L is produced by the transverse magnetic field annealing although the present cavity for the J-PARC adopts the magnetic alloy, FT3M, which is annealed without magnetic field. After the test production using a large spectrometer magnet in 2011, a dedicated production system for the FT3L cores was assembled in 2012. This setup demonstrated that we can produce material with 2 times higher 0 p Qf product compared to the cores used for present cavities. In this summer, the production system was moved to the company from J-PARC and is used for mass production of 280 FT3L cores for the J-PARC MR. The cores produced in the first test production are already used for standard machine operation. The operation experience shows that the power loss in the cores was reduced significantly as expected.

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Simulation of longitudinal beam manipulation during multi-turn injection in J-PARC RCS

Cited by 27 publications

References 5 publications

Achievement of a low-loss 1-MW beam operation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

Achievement of a low-loss 1-MW beam operation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

Beam loss reduction by injection painting in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

Development of a high gradient rf system using a nanocrystalline soft magnetic alloy

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