Improvement of Electron Intensity Reduction System at SLRI Beam Test Facility

Synchrotron Light Research Institute (SLRI) has been commissioning an additional experimental station, a Beam Test Facility (BTF), to the SLRI accelerator complex. SLRI BTF was constructed to provide electron test beams with energy ranging from 40 MeV up to 1.2 GeV and with tunable electron intensity from a few to millions of electrons per burst. In order to obtain low intensity of test beams, an approach using a metal target together with an energy selector has been employed. A combination of a target chamber installed at the high energy beam transport line and the existing 4-degree bending magnet that is used as an energy selector first produced low intensity test beams. However, the test beam profile was not well determined due to the insufficient bending angle of the energy selector and high primary beam energy. Another approach mounting a target chamber at the low energy beam transport line and using the synchrotron booster as an energy selector was implemented to avoid such problems. Once in operation, the facility will have the potential to service calibration and testing of high energy detectors as well as beam diagnostic instrumentations.