Author: Takano, S.
Paper Title Page
MOPA48 Measurement of Temporal Resolution and Detection Efficiency of X-ray Streak Camera by Single Photon Images 171
 
  • A. Mochihashi, M. Masaki, H. Ohkuma, S. Takano, K. Tamura
    JASRI/SPring-8, Hyogo-ken, Japan
 
  Funding: This work was partly supported by MEXT Grant-in-Aid for Young Scientists (B) Grant number 21740215.
In the third generation and the next generation synchrotron radiation light sources, the electron beam bunch length of ps ~ sub-ps is expected to be achieved. An X-ray streak camera (X-SC) can directly measure the temporal width of X-ray synchrotron radiation pulse. The temporal resolution of X-SC depends on the initial velocity distribution of the photoelectrons from a photocathode which converts the X-ray photons to the photoelectrons. To measure the temporal resolution of the X-SC, we have observed 'single photon' streak camera images and measured the temporal spread of the images. By this 'single photon' experiment, we have evaluated the dependence of the temporal resolution and the detection efficiency on the photon energy. We have also tried to evaluate the dependence of the temporal resolution and the detection efficiency on the thickness of the photocathode. For this purpose, we have developed a multi-array type CsI photocathode with 3 different thickness of the photocathode. The experimental setups, and the results of the measurements of the temporal spread and the detection efficiency of the single photon events will be presented.
 
 
MOPB52 Status and Activities of the SPring-8 Diagnostics Beamlines 186
 
  • S. Takano, M. Masaki, A. Mochihashi, H. Ohkuma, M. Shoji, K. Tamura
    JASRI/SPring-8, Hyogo-ken, Japan
  • H. Sumitomo, M. Yoshioka
    SES, Hyogo-pref., Japan
 
  At SPring-8 synchrotron radiation (SR) in both the X-ray and the visible bands is exploited in the two diagnostics beamlines. The diagnostics I beamline has a dipole magnet source. The beam size is measured by imaging with the zoneplate X-ray optics. Recently, the transfer line of the visible light has been upgraded. The in-vacuum mirror was replaced to increase the acceptance of the visible photons. A new dark room was built and dedicated to the gated photon counting system for bunch purity monitoring. To improve the performance, the input optics of the visible streak camera was replaced by a reflective optics. Study of the power fluctuation of visible SR pulse is in progress to develop a diagnostic method of short bunch length. The diagnostics II has an insertion device (ID). To monitor stabilities of the ID photon beam, a position monitor for the white X-ray beam based on a CVD diamond screen was installed. A turn-by-turn diagnostics system using the monochromatic X-ray beam was developed to observe fast phenomena such as beam oscillation at injection for top-up and beam blowups caused by instabilities. Study of temporal resolution of the X-ray streak camera is also in progress.  
 
TUPB63 Development of Turn-by-turn Beam Diagnostic System using Undulator Radiation 492
 
  • M. Masaki, A. Mochihashi, H. Ohkuma, S. Takano, K. Tamura
    JASRI/SPring-8, Hyogo-ken, Japan
 
  At the diagnostic beamline II (BL05SS) of the SPring-8 storage ring, a turn-by-turn beam diagnostic system using undulator radiation has been developed to observe fast phenomena such as stored beam oscillations during the top-up injections, blowups of beam size and energy spread coming from the instabilities of a high current single bunch and so on. The fast diagnostic system observes a spatial profile of the undulator radiation on a selected harmonic number. Especially, the higher harmonic radiations than the 10th-order are sensitive to the energy spread. A fluorescence screen (YAG:Ce) with afterglow of several tens of nano-second converts the radiation profile into visible light image. The imaging optics makes the horizontal and vertical profiles as two line images by one-dimensional focusing using cylindrical lenses. A fast-gated CCD camera with image intensifier simultaneously captures the two line images. The kinetics readout mode of the fast CCD camera is used to register the spatial profiles of several tens of turns in one flame. The principle and experimental setup of the turn-by-turn diagnostic system, and examples of beam observations will be presented.