Transverse emittance growth caused by space-charge-induced resonance

Yasui, Takaaki; Igarashi, S.; Sato, Yoichi; Koseki, T.; Ohmi, K.

doi:10.1103/physrevaccelbeams.23.061001

Cited by 3 publications

(1 citation statement)

References 5 publications

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“…6). Besides, the integer resonance of nx = 22 is found not to be a 4 th order structure resonance unlike the resonance of nx = 21 and it is then weaker than nx = 21 [5]. There is a 4 th order structure resonance of 2nx -2ny = 0.…”

Section: Search For the New Working Pointmentioning

confidence: 77%

Study on the Beam Intensity Upgrade of J-PARC Main Ring

Igarashi

Ohmi

Sato

et al. 2021

Proceedings of the 3rd J-Parc Symposium (J-Parc2019)

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The beam intensity upgrade of the main ring of the Japan Proton Accelerator Research Complex (J-PARC) have been studied with simulations. The main ring delivered 30 GeV proton beams with the beam power of 500 kW at maximum to the neutrino facility in the recent operation. The number of accelerated protons was 2.61×10 14 protons per pulse (ppp). The upgrade plan aims at a beam power of 1.3 MW with reduced cycling time of 1.16 s compared to the present cycle time of 2.48 s. Upgrades of the magnet power supplies and RF system are in progress to achieve faster cycling. Furthermore, an intensity upgrade to 3.3×10 14 ppp is necessary, while keeping the beam loss under control to reduce residual radiation. The high intensity operation has been simulated with the particle tracking program SCTR, taking space charge effects into account. The simulations were performed for the present beam intensity to reproduce the present status of the beam loss and for the target beam intensity to estimate the beam loss. We studied the interaction of the beam with structure resonances as main cause of the beam loss. Possible alternative operational tunes were explored to improve beam survival.

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Section: Search For the New Working Pointmentioning

confidence: 77%

Study on the Beam Intensity Upgrade of J-PARC Main Ring

Igarashi

Ohmi

Sato

et al. 2021

Proceedings of the 3rd J-Parc Symposium (J-Parc2019)

Self Cite

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Beam optics for the compensation of third-order structure resonances

Yasui

Igarashi

Sato

et al. 2021

Progress of Theoretical and Experimental Physics

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The third-order structure resonance due to sextupole magnetic fields was compensated in the Japan Proton Accelerator Research Complex (J-PARC) main ring synchrotron (MR) using new beam optics. In the present optics, the third-order structure resonance νx − 2νy = −21 was so strong that the working point was limited. The new optics cancels the resonance by adjusting the phase advances in the arc sections. The resonance compensation was verified by aperture survey simulations and further demonstrated by three types of experiments. First, the transverse coupling measurements were performed. The coupling was observed only for the optics without the compensation. It was also verified with the tracking simulation. Second, the beam losses were measured using present and new optics. The measured beam losses were noticeably reduced at the tunes around the resonance using the new optics. The beam loss reduction was also verified with the space charge tracking simulation. Third, Fourier analyses of the transverse dipole oscillations were conducted for both optics. Fourier spectra derived from the resonances were observed, and their peaks were clearly suppressed with the new optics. It was also consistent with the results of the space charge simulations.

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Suppression of the eighth-order space-charge-induced resonance

Yasui

Kurimoto

2022

Phys. Rev. Accel. Beams

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Transverse emittance growth caused by space-charge-induced resonance

Cited by 3 publications

References 5 publications

Study on the Beam Intensity Upgrade of J-PARC Main Ring

Study on the Beam Intensity Upgrade of J-PARC Main Ring

Beam optics for the compensation of third-order structure resonances

Suppression of the eighth-order space-charge-induced resonance

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