TUP047 　ポスター①　 10月18日 会議室P 13:30-15:30

LIPAc Phase-B+のRFQ/SRF用RF増幅系におけるRFノイズとリークの問題

RF noise and leakage issue in RF power amplifier chains for driving RFQ and SRF cavities in the Phase-B+ of LIPAc

○廣澤 航輝，久保 直也，春日井 敦（QST/六ケ所研究所），マルチェナ アルバロ（BTESA），モヤ イバン（F4E），斎藤 健二（NIFS），小林 仁（KEK）

○Kouki Hirosawa, Naoya Kubo, Atsushi Kasugai (QST/Rokkasho), Alvaro Marchena (BTESA), Ivan Moya (F4E), Kenji Saito (NIFS), Hitoshi Kobayashi (KEK)

LIPAc (Linear IFMIF Prototype Accelerator) is a EU-JA collaboration 9 MeV and 125 mA CW hadron linac that aims to validate the technology will be used in the IFMIF accelerator (40 MeV, 2 x 125 mA CW). The RF accelerating system of LIPAc consists of three types of components: RFQ cavity, buncher cavities, and superconducting half wave resonators (SRF). The RF control system of LIPAc is designed to optimized CW operation, and 8 high power RF amplifier chain is used for each RFQ cavity and SRF cavities, individually. After amplification by tetrodes, a Y-stripline ferrite circulator controls RF with nominal output power 220kW for RFQ and 105kW for SRF. During the Phase-B+ beam commissioning and RFQ conditioning campaign started from FY2021, strong RF signal with similar pulse shape for set RF parameters had been detected by using spectrum analyzer. The RF leak can make noise floor and unexpected malfunctions for each diagnostic. By measuring the noise from the cables and free space, we could find one of critical sources of RF leakage. In this report, measurement and analyzation results, an idea to fix, and discussion about other candidate of the large RF leakage will be reported.