THE MEASUREMENTS OF THE LONGITUDINAL BEAM PROFILE ON THE PREINJECTOR VEPP-5.

For effective work of preinjector VEPP-5 it is necessary 3 ns bunch with charge 1*10**10 electrons from termogun compress to bunch with 40 ps duration on the positron target. A new streak-camera with RF cavity on the main linac frequency is used. Streak-camera with circle scanning allows see 350 ps single light signal with sub-ps resolution. An additional slow scanning can obtain the trochoidal scanning. Thus one can see with picoseconds resolution and with less then 1psec synchronization the train of ten bunches which are spacing by 350psec. The results of worked streak-camera with RF-cavity for circle scanning are presented.