Beam profile monitor for PAL-XFEL

초록

Abeam profile monitor has been developed for precise measurement of the electron beam size at the X-ray free-electron laser (XFEL). Given the XFEL’s high beam energy, accurate alignment of optical transition radiation (OTR) is essential due to the small opening angle. To address this, a newly designed monitor enables prealignment of the optical system before installation. The target holder incorporates a specialized configuration to remove coherent optical transition radiation (COTR) arising from the XFEL’s ultra-short bunch length, following a concept similar to that used at SwissFEL. Furthermore, the holder layout was optimized to minimize the vacuum chamber dimensions while increasing the separation between the mirror and the beam path to eliminate diffraction radiation. Experimental results confirm that COTR was effectively removed, and no diffraction radiation was observed in the beam images.

키워드