First high-power model of the annular-ring coupled structure for use in the Japan Proton Accelerator Research Complex linac

Ao, Hiroyuki; Yamazaki, Yoichi

doi:10.1103/physrevstab.15.011001

Cited by 13 publications

(8 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As mentioned in the last section, the injector linac upgrades have been completed recently; the output energy of the linac beam was upgraded from 181 MeV to the design value of 400 MeV in 2013 by adding an annular-ring coupled structure (ACS) linac [6], and then the peak current of the linac beam was increased from 30 mA to the design value of 50 mA in 2014 by replacing the front-end system (ion source [7] and rf quadrupole [8]). Via these series of injector linac upgrades in 2013 and 2014, all hardware parameters to realize the RCS design output beam power of 1 MW were in place.…”

Section: Outline Of J-parc 3-gev Rcsmentioning

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

View full text Add to dashboard Cite

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.

show abstract

Section: Outline Of J-parc 3-gev Rcsmentioning

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

View full text Add to dashboard Cite

show abstract

“…By using ANSYS [10], it was estimated that the accelerating-cell frequency would decrease by 0.04 MHz during high-power operation, while the frequency change of the coupling cell would be negligible [11]. In addition, the estimated thermal detuning for the accelerating cell was in good agreement with the high-power test result obtained using buncher 1 [8]. Thus, these values were adopted also for M01.…”

Section: Designed Frequency Before Brazingmentioning

confidence: 94%

“…The first ACS prototype cavity (buncher 1) for use in the J-PARC linac was developed to confirm the feasibility of its fabrication and frequency tuning, as well as to confirm that it can meet the performance required by the J-PARC linac [8]. After that, another prototype cavity (buncher 2) was also fabricated; however, these prototype ACSs were buncher cavities that included only 10 accelerating cells in total.…”

Section: Introductionmentioning

confidence: 99%

First annular-ring coupled structure cavity for the Japan Proton Accelerator Research Complex linac

Ueno

Hirano

et al. 2012

Phys. Rev. ST Accel. Beams

Self Cite

View full text Add to dashboard Cite

The first annular-ring coupled structure (ACS) cavity for the Japan Proton Accelerator Research Complex (J-PARC) linac has been developed in order to confirm and establish its fabrication processes. This cavity includes 34 accelerating cells, which is 3.4 times as many as the prototype cavity (buncher) of the J-PARC ACS. The cell frequencies before brazing were tuned within the required accuracies. After brazing, the accelerating-and coupling-mode frequencies were 972.19 and 972.63 MHz on average, respectively, which were higher than the operating frequency of 972 MHz. Although the acceleratingmode frequency can be corrected to 972 MHz using adjustable plungers, these frequency errors adversely affected the on-axis electric field. This cavity was successfully conditioned up to 1.6 MW. This power corresponds to an accelerating field of 4:7 MV=m, which is 10% higher than the design value of 4:2 MV=m. In order to find the issue caused by the excited coupling cells, this cavity was also conditioned at the higher and lower frequencies that were detuned from the operating frequency of 972 MHz. Here we present the frequency tuning processes, the low-level rf measurements, and the high-power test results. We also discuss the most reasonable scenario for frequency tuning in future work.

show abstract

“…The linac will be upgraded in the 2013 summer maintenance period; the output energy will be improved to 400 MeV with the addition of an annular coupled structure (ACS) linac [8], and the maximum peak current will be increased to 50 mA (30 mA at the moment) by replacing the front-end system (ion source and radio-frequency quadrupole linac). After that, the RCS will aim at our final goal of 1 MW output.…”

Section: Layout and Design Parametersmentioning

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

View full text Add to dashboard Cite

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.

show abstract

First high-power model of the annular-ring coupled structure for use in the Japan Proton Accelerator Research Complex linac

Cited by 13 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

First annular-ring coupled structure cavity for the Japan Proton Accelerator Research Complex linac

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

Contact Info

Product

Resources

About