Speaker
Description
A new linear accelerator was constructed for the New SUBARU (NS), a 1.5 GeV synchrotron radiation facility. The accelerating frequencies used at the new linac are 238 MHz, 476 MHz, 2856 MHz (SB), and 5712 MHz (CB). The required accuracy for the amplitude and phase of the accelerating field are 8E-4 and 0.2 degree, respectively in the most severe case. Also, the master trigger of the linac must be synchronized with both the aimed bucket timing of the ring and the linac master clock. To fulfill these requirements, the timing system and Low-Level RF (LLRF) control system were developed using the modules of Micro Telecommunication Computing Architecture 4 (MTCA.4) standard. The master trigger and the clock of the linac are generated at the master unit located near the LLRF station of the ring, and are delivered to four LLRF subunits of the linac through the optical links. The amplitude and phase of the accelerating field are controlled based on In-phase and Quadrature (IQ) scheme. The achieved stabilities in rms are 7E-4 in amplitude and 0.2 degree in phase, which satisfy the requirements. The operation of the NS has been carried out stably since April 2021 without any significant faults.
