Development of a high-resolution beam profile monitor using zone plates

点击翻译按钮获取中文摘要

By this project, performance and reliability of this beam profile monitor was greatly improved and this monitor became fully practical. The research results are summarized below.1. Background due to transmitted X-rays through the zone plates was much reduced by an X-ray pinhole mask installed around the focus point of the first zone plate.2. Vibrations of the zone plates were measured by seismometers and their effect on spatial resolution of the monitor was evaluated. As a result, the vibration effect was negligibly small even by taking magnification of the imaging system into account and the configuration of the zone plates insensitive to vibrations was studied.3. An estimation method of spatial resolution of the monitor and the effects of the zone-plate alignment errors on the resolution was established by using a developed computer code based on wave optics. By this code, the tolerable ranges of the alignment errors were also obtained. Analysis using a developed ray-tracing code was successfully performed.4. A system for synchronization with injection was added to this monitor. As a result, we succeeded in obtaining the damping time of the KEK-ATF damping ring with the damping wiggler on and off by measuring the beam size as function of the time after injection. The synchronization system enabled us to do various beam diagnoses related to injection.5. Time resolution of the monitor was greatly improved by installing the fast mechanical shutter around the focusing point of the first zone plate. As a result, the effect of the fast position movement of the beam image on the beam size measurement was removed.6. Remote control of the monitor system from the accelerator control room was realized. Thus measurements of beam profiles and sizes can be linked with control of the accelerator and easily be done at any time during the accelerator operation.