• P.K. Saha, N. Hayashi, H. Hotchi, K. Yamamoto, M. Yoshimoto
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• Y. Irie
  KEK, Ibaraki
• T. Toyama
  J-PARC, KEK & JAEA, Ibaraki-ken

The beam loss issues connected to the nuclear scattering together with the multiple Coulomb scattering at the charge-exchange foil during the multi-turn injection has been studied in detail for the RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex). Recently, during the beam commissioning of RCS, some experimental data related to such issue has been taken and thus a comparison of the measured beam loss to the estimated one is reported in this paper. When the beam loss from such a source is unavoidable, a realistic estimation is quite important for a fair design of the injection system and the vicinity in order to reduce especially, the uncontrolled beam loss.

• K. Yamamoto
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• T. Toyama
  J-PARC, KEK & JAEA, Ibaraki-ken

The RCS of J-PARC accelerator complex has been commissioned since September 2007. By a study of one year, we were able to demonstrate more than 200kW operation. In such high intensity operation, the electron cloud effect may have an important roll for the accelerator limitation. we estimated the electron emission from the collimator surface of RCS by a simulation.

• T. Toyama, D.A. Arakawa, A. Arinaga, Y. Hashimoto, S. Hiramatsu, S. Igarashi, S. Lee, H. Matsumoto, J.-I. Odagiri, M. Tejima, M. Tobiyama, N. Yamamoto
  KEK, Ibaraki
• K. Hanamura, S. Hatakeyama
  MELCO SC, Tsukuba
• H. Harada
  JAEA, Ibaraki-ken
• N. Hayashi, K. Yamamoto
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• K. Satou
  J-PARC, KEK & JAEA, Ibaraki-ken

Beam commissioning of the J-PARC MR has been going on from May 2008. The beam was one bunch of 4·10¹¹ protons, nearly one hundredth of the design value. Here describe performances of the beam diagnostic devices: DCCT's, BPM's, BLM's, profile monitors and tune meters. Diagnostic design for the design intensity will be also included.

Slides

• Y. Shobuda
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• Y.H. Chin, M. Ikegami, T. Toyama
  KEK, Ibaraki

Kicker magnets are ones of dominant sources of impedances in the 3GeV Rapid Cycling Synchrotron (RCS) at Japan Proton Accelerator Research Complex (J-PARC). They may be limiting factors in achieving high intensity beams. Recently, the 300kW beam was accomplished at 3GeV RCS, while no instability was observed. In this paper, the space-charge effects are studied as beam stabilization effects.