SAP006 　ポスターセッション１　 8月3日 豊田講堂１階アトリウム 13:00 - 15:00

Linacのパルスベンディングマグネット付近のビームロス調査

Beam loss investigation near the pulse bending magnet of KEKB Injector Linac

○矢野 喜治，道園 真一郎，福田 茂樹，佐波 俊哉（高エネ研）

○Yoshiharu Yano, Shinichiro Michizono, Shigeki Fukuda, Toshiya Sanami (KEK)

Linac delivered the electron of 8GeV to HER-KEKB, and delivered the positron of 3.5 GeV to LER-KEKB. Furthermore, the electron of 2.5 GeV is supplied to PF and the electron of 3 GeV is supplied to PF-AR. Linac should be operated to deliver the beam to HER, LER, and PF every 20msec. The pulse magnet (BP_58_1) installed downstream of Linac control the beam distribution. The measured data of BPM show that the charge quantity of PF beam is decreasing before and behind this magnet. Investigation of the beam loss using an optical fiber has shown that the beam loss has occurred in the straight section of the BP_58_1 lower stream. We have investigated the beam loss of the inside magnet, and the magnet circumference. In the present operating condition, we found that the beam loss is very large in the branch duct of the magnet. The dose of radiation under operation of a place with many beam losses was measured in TLD batch, and it compared with the optical fiber loss monitor's data. A lot of beam loss had occurred near the branch duct. The duct of PF beam line of about 100 m of lower streams of a pulse bending magnet and the residual radioactivity of the flange were measured.