WEOB5 　ハドロン加速器/加速器技術(真空)　 8月30日 13号館1326教室 10:30-10:50

J-PARC 3GeVにおける負水素イオンのレーザー荷電変換の状況

Status of the laser stripping of H- beam at J-PARC RCS

○サハ プラナブ，原田 寛之，金正 倫計（原子力機構, J-PARC センター），米田 仁紀，道根 百合奈（電通大, レーザー研），佐藤 篤（NAT），柴田 崇統（KEK/J-PARC）

○Pranab Saha, Hiroyuki Harada, Michikazu Kinsho (JAEA, J-PARC), Hitoki Yoneda, Yurina Michine (UEC, ILS), Atsushi Sato (NAT), Takanori Shibata (KEK/J-PARC)

To overcome the issues and limitation of the stripper foil used for H- charge-exchange injection, we proposed an alternative way of H- stripping by using lasers. To establish the method, a POP (proof-of-principle) demonstration for 400 MeV H- stripping by using only lasers is under preparation. The R&D of a YAG laser system including a cavity to significantly reduce the seed laser power have been developed and tested for 3 MeV H- beam neutralization. The R&D of highly efficient material coating is underway to minimize the light losses at the vacuum windows during multi-pass. As a result, nearly 30 times light intensity gain can be achieved to scale down the seeder pulse energy to around 0.015 mJ/pulse to accumulate more than 4 mJ energy in the cavity by 32 passes and to realize more than 90% stripping efficiency. The R$D of the UV laser as well as installation of the YAG laser system for the POP study at 400 MeV are also under progress to start the 1st experiment in 2023.