• T. Fujita, H. Hanaki, T. Nakazato
  JASRI/SPring-8, Hyogo-ken
• K. Akai, K. Ebihara, T. Furuya, K. Hara, T. Honma, K. Hosoyama, A. Kabe, Y. Kojima, S. Mitsunobu, Y. Morita, H. Nakai, K. Nakanishi, M. Ono, Y. Yamamoto
  KEK, Ibaraki
• M. Matsuoka, K. Sennyu, T. Yanagisawa
  MHI, Tokyo
• M. Monde
  Mitsubishi Heavy Industries Ltd. (MHI), Takasago

We have been de­vel­op­ing a sys­tem to gen­er­ate a short pulse X-ray using crab cav­i­ties at SPring-8 Stor­age Ring. The ring holds 30-m long straight sec­tions and the ver­ti­cal beam size at the cen­ter of the straight sec­tions is 6.5 mi­crom­e­ters in stan­dard de­vi­a­tion. If we in­stall four su­per­con­duct­ing crab cav­i­ties and a mi­ni-pole un­du­la­tor in one of the straight sec­tions, we can con­vert the time dis­tri­bu­tion of the elec­tron bunch into the spa­tial dis­tri­bu­tion. After slic­ing the emit­ted pho­tons with ver­ti­cal slits, we can ob­tain a sub-pi­cosec­ond X-ray pulse. In this scheme, the max­i­mum rep­e­ti­tion rate of the short pulse X-ray is the same as the ac­cel­er­a­tion fre­quen­cy of the ring (508MHz) and user ex­per­i­ments at other beam-lines are not dis­turbed by this short pulse gen­er­a­tion. We are plan­ning to in­stall KEKB type crab cav­i­ties as ver­ti­cal de­flec­tors. Phase fluc­tu­a­tion among crab cav­i­ties must be re­duced less than 14 mdeg in order to avoid resid­u­al de­flec­tion in the ver­ti­cal di­rec­tion. In this paper, we re­port an overview of the short pulse gen­er­a­tion scheme and top­ics of hard­ware de­vel­op­ment for sta­bi­liza­tion of the RF phase fluc­tu­a­tion.

Slides