Asaka, T.

Paper	Title	Page
TUPMA067	New Timing System for the L-band Linear Accelerator at Osaka University	208
	S. Kashiwagi, G. Isoyama, R. Kato, S. Suemine ISIR, Osaka T. Asaka, Y. Kawashima JASRI/SPring-8, Hyogo-ken
	A highly precise and flexible timing system has been developed for the L-band linac at ISIR, Osaka University. It provides four RF signals and several timing signals for operation of the linac and for experiments with the linac. In order to realize long-term stability of the timing system and hence operation of the linac, a rubidium atomic clock producing a 10 MHz RF signal with the fractional stability of 10-15 is used as a time base for a synthesizer used as a master oscillator for generating the acceleration frequency of 1.3 GHz. The 1.3 GHz signal from the master oscillator is directly counted to produce the four RF signals and the clock signal of the timing system at 27 MHz. The master timing signals for linac operation is taken from the AC line frequency and it is synchronized with the 27MHz clock signal precisely. To make an arbitrary delayed timing signal, a standard digital delay generator is used to make a gate signal for a GaAs RF switch, with which one of the 27MHz clock pulses is sliced out to generate the delay timing signal. Any timing signal can be made in an interval of 37 ns and the timing jitter of the delayed signal is achieved to be as short as 2 ps.
THC3MA05	Bunch Compression using the Transport Line and Short Bunch revolving in NewSUBARU	619
	S. Suzuki, T. Asaka JASRI/SPring-8, Hyogo-ken Y. Hisaoka, T. Matsubara, T. Mitsui, Y. Shoji NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo
	We have demonstrated the idea of circulating a short, intense linac bunch for some tens of turns in an isochronous ring. We compressed a bunch from the SPring-8 linac to a few picoseconds rms by means of an energy compression system and a beam transport line from the linac to NewSUBARU. The NewSUBARU storage ring was set to a quasi-isochronous condition and the bunch circulated for some tens of turns after injection while maintaining the short bunch length. And we measured the coherents synchrotron radiation at 90-140GHz by semiconducter detector. The bunch length is maintained in about 20 microseconds, but the CSR power decreases little by little.
	Slides