A beam position monitor for the diagnostic line in MEBT2 of J-PARC linac

8th International Particle Accelerator Conference

Miura, A.^1 ; Tamura, J.^1 ; Kawane, Y.^1

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

319-1195, Japan^1

关键词: Beam displacement;    Beam position monitors;    Beam positions;    Correction function;    Japan proton accelerator research complexes;    Negative hydrogen ions;    Neutral hydrogen;    Orbit corrections;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/874/1/012081/pdf
DOI  :  10.1088/1742-6596/874/1/012081

来源: IOP

【 摘 要 】

In the linac of the Japan Proton Accelerator Research Complex (J-PARC), the neutral hydrogen (H0) beam from the negative hydrogen ion (H-) beam is one of key issues in mitigating beam losses. To diagnose H0particles, we installed a set of beam-bump magnets to generate a chicane orbit of the H-beam. The beam position monitors (BPMs) in the beam line are used for orbit correction to maintain the beam displacement within 2.0 mm from the duct center. To measure the beam displacement under different drive currents of the beam-bump magnets, a new wide-range BPM was designed and manufactured to evaluate the horizontal beam position by using a correction function to compensate for non-linearity. We also employed the beam profile monitor (WSM: wire scanner monitor) to measure the H-beam profile, which helped us to compare the beam position measurements. In this paper, the design and the performance of the wide-range BPM are described. In addition, we present a comparison of the beam position measured by the BPM and the WSM.