THP024 　ポスター②　 8月1日 2F交流ラウンジ 13:00-15:00

コンパクトERLのCW 運転用の入射器設計

Injector design for Compact ERL CW operation

○田中 織雅（高エネルギー加速器研究機構）

○Olga Tanaka (High Energy Accelerator Research Organization (KEK))

Achieving continuous wave (CW) operation in a Compact Energy Recovery Linac (cERL) injector requires meticulous tuning and accurate model preparation. However, a startup issue arose on November 27th. The buncher response deviated from expectations, and an unexpectedly high field in INJ1 necessitated lowering the field in INJ2-3. This revealed shortcoming in the initial RF optimization. The culprit? The standard two-step optimization process, which minimizes transverse emittance vs bunch length followed by longitudinal emittance vs bunch length minimization, was incomplete. Only the first step was performed. Fortunately, after completing the full optimization process, the final injector parameters closely resembled those achieved during tuning. This experience underscores the importance of a step-wise optimization approach that factors in actual injector parameters like injection energy, gun voltage, and initial beam distribution. Moreover, it highlights the need for continuous model refinement to minimize discrepancies between the model's predictions and the real injector's behavior – a key focus of our current study.