RESUMO
A high-repetition linear accelerator with multibeamline operation for X-rays allows users to perform multiple simultaneous experiments with an X-ray free-electron laser (XFEL) at lower actual cost per user while maintaining the availability of the laser. As the first step toward a higher pulse repetition rate (PRR), we developed radio frequency (RF) components at 5712 MHz and tested them for their feasibility at an RF PRR of 120 pulses per second (pps). To increase the RF PRR from the present value of 60 pps-at the SPring-8 Angstrom compact free-electron laser-to 120 pps, we re-examined the thermal designs of the present RF components for the XFEL. With the proposed design, the newly developed RF components worked well at 120 pps. The insulation-oil temperature in the high-voltage tank of the klystron modulator was below 70 °C, which is less than the operational temperature limit. At 5712 MHz, this is now the highest RF pulse repetition frequency yet to be achieved and represents a major step toward higher PRRs.
RESUMO
Since an X-ray Free Electron Laser (XFEL) facility is a linac-based single-user machine, a multi-beamline mode of operation, which improves the efficiency of user experiments, is critical for accommodating users' rapidly increasing demand for beamtime. A key supporting technology is a highly stable pulsed power supply (PS), which enables stable XFEL operations by precisely switching the beam route. We developed a high-power pulsed PS to drive a kicker magnet installed in a SACLA's beam switching system. SiC MOSFETs were adapted as switching elements to reduce the required size and to increase the electric power efficiency. The PS we developed provides two key capabilities: (i) a high current stability of 20 ppm (peak-to-peak) at a peak power of 0.24 MW and (ii) generation of controllable, bipolar, and trapezoidal current waveforms at 60 Hz. This paper describes the overall concept, the detailed design, the performance achieved, and the initial beam test results.