Annual Review 2024-2025

A N N U A L R E V I E W 2 0 2 4 / 2 5 44 M A C H I N E , B U I L D I N G S A N D I N F R A S T R U C T U R E Figure 2. CPMU-5 installed in the storage ring, as viewed from the storage ring roof. Figure 3. The prototype Diamond-II injection stripline kicker installed in the Booster-to-Storage Ring transfer line. Installation of CPMU-5 The 5th Cryogenic Permanent Magnet Undulator (CPMU) designed and built in-house was successfully installed in November 2024 (Fig. 2). This was the last Diamond insertion device (ID) upgrade to be carried out before commencing the preparation of new IDs for Diamond-II. Testing the Diamond-II prototype injection stripline kicker and pulser We are planning a fully transparent top-up injection in Diamond-II whereby the process of injecting additional charge does not materially impact on the quality of the beamline source points. This will be achieved using a novel single bunch “kick-and-cancel” injection scheme which requires the use of high voltage stripline kickers. As there was little in-house experience of designing such systems, a prototype stripline kicker and power supply were developed. These prototypes were tested using the existing test stand in the booster to storage ring transfer line (Fig. 3). Electron bunches were sent through the kicker and then onto the last beam dump before the storage ring. Fluorescent screen detectors downstream of the kicker were used to measure the transverse location. By measuring with and without power applied we were able to determine that the angular kick generated was 65 µrad. This compared well with the analytically calculated value of 54 µrad with the applied voltage of ±5.3 kV. Further testing in the storage ring is planned to assess thermal behaviour, impact on beam impedance and full ±20 kV operation. The results from this exercise will inform the final Diamond-II designs and reduce the risk of the overall injection kicker project.