Speaker
Ippei Yamada
(J-PARC Center, Japan Atomic Energy Agency)
Description
In low energy beam transport (LEBT), space charge neutralization/compensation (SCN) plays an important role in focusing a beam and keeping the emittance low for a high intensity hadron accelerator. At J-PARC LEBT, the gas pressure is in a range from 10$^{-1}$ to 10$^{-4}$ Pa with H$_2$ gas flowing out from the ion source, and sufficient SCN is considered to occur for a 50 mA, 50 keV, 500 $\mu$s negative hydrogen ion beam. However, we experimentally measured a phase-space distribution at an RFQ inlet, which implies that the distribution is affected by a non-linear SC effect and the degree depends on the beam current. We are investigating how the beam emittance grows in a neutralized beam line with a PIC code simulation.
Author
Ippei Yamada
(J-PARC Center, Japan Atomic Energy Agency)
Co-authors
Dr
Kunihiro Kojima
(J-PARC Center, Japan Atomic Energy Agency)
Dr
Motoki Chimura
(J-PARC Center, Japan Atomic Energy Agency)