Author: Nagai, R.
Paper Title Page
WG1007
 Status of 500-kV DC Gun at JAEA  
 
  • N. Nishimori, R. Hajima, R. Nagai
    JAEA, Ibaraki-ken, Japan
  • Y. Honda, M. Kuriki, T. Miyajima, M. Yamamoto
    KEK, Ibaraki, Japan
  • H. Iijima
    HU/AdSM, Higashi-Hiroshima, Japan
  • M. Kuwahara, T. Nakanishi, S. Okumi
    Nagoya University, Nagoya, Japan
  
  We have developed a 500-kV DC gun at JAEA. It is difficult to apply DC high voltage on a ceramic insulator with a stem electrode because of field emission from the electrode. By employing a segmented insulator with rings which guard the ceramics from the field emission, we succeeded in applying 500-kV on the ceramics for eight hours without any discharge in Dec. 2009. This high voltage testing was performed with a simple configuration without NEG pumps and electrodes. In Jul. 2009, we reached 380kV with electrodes in place before we suffered field emission problem from the cathode electrode. Then we generated beam at 300kV in Nov. 2010. After beam generation we have continued high voltage testing with electrodes in place. In Jul. 2011, we reached 510kV, before suffering another field emission problem from cathode electrodes. The problem may be attributed to small dust inside our gun chamber. We are trying to reach 550kV by solving the small dust problem. Our current status of development will be presented in the workshop.  
slides icon Slides WG1007 [6.486 MB]  
 
PSP021 Design of ERL Spoke Cavity for Non-destructive Assay Research 140
 
  • M. Sawamura
    JAEA/ERL, Ibaraki, Japan
  • R. Hajima, R. Nagai, N. Nishimori
    JAEA, Ibaraki-ken, Japan
  
  We are proposing non-destructive assay system of nuclear materials with laser Compton scattering combined with an energy-recovery linac and a laser. To construct this system for nuclear safeguards and security purpose, it is important to make the accelerating cavity small. The spoke cavity has advantages over the elliptical cavity to adopt for our proposing system. We are designing a spoke cavity favorable to compact cavity. Design optimization calculation of the spoke cavity shape is being carried out using 3D electro-magnetic field simulation code with multi-objective genetic algorithm. The results will be presented.