Bunch shape monitor development in J-PARC linac

8th International Particle Accelerator Conference

Miura, A.^1 ; Tamura, J.^1 ; Liu, Y.^2 ; Miyao, T.^2

J-PARC Center, Japan Atomic Energy Agency, 2-4, Shirakata-Shirane, Tokai, Ibaraki

319-1195, Japan^1

J-PARC Center, High Energy Accelerator Research Organization, 203-1, Shirakata, Tokai, Ibaraki

319-1106, Japan^2

关键词: Beam loss;    Key Issues;    Leakage magnetic field;    Nuclear research;    Phase width;    Quadrupole magnets;    Setpoints;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/874/1/012080/pdf
DOI  :  10.1088/1742-6596/874/1/012080

来源: IOP

【 摘 要 】

In the linac at the Japan accelerator research complex (J-PARC), we decided to use bunch shape monitors (BSMs) as phase-width monitors. Both centroid-phase set point at the frequency jump from SDTL (324 MHz) to ACS (972 MHz) and phase-width control are key issues for suppressing excess beam loss. BSM was designed and developed at the Institute for Nuclear Research, Russia. Because the BSM was first used between acceleration cavities, we need to improve it to protect it from the leakage-magnetic field of the quadrupole magnets and from outgassing impacts on the cavities. In this paper, we introduce these improvements to the BSM for the adoption of the location nearby the acceleration cavities.