• S.H. Kim, M.-H. Cho, S.D. Jang, W. Namkung, S.J. Park, H.R. Yang
  POSTECH, Pohang, Kyungbuk
• K.H. Chung, K. Lee
  KAPRA, Cheorwon
• J.-S. Oh
  NFRI, Daejon
• Y.G. Son
  PAL, Pohang, Kyungbuk

An intense L-band electron linac is now being commissioned at ACEP (Advanced Center for Electron-beam Processing in Cheorwon, Korea) for irradiation applications. It is capable of producing 10-MeV electron beams with the 30-kW average beam power. The constant-impedance accelerating structure is operated under fully-beam-loaded condition with the RF power of peak 25 MW and the beam current of 1.45 A. The total attenuation coefficient of the structure is 0.17 and the RF filling time is 0.9 μs along the 2.3-m accelerating structure. To suppress the energy spread due to the transient beam loading effect, we consider three methods: modulating the beam current amplitude, modulating the RF amplitude, and adjusting the beam injection time. In this paper, we calculate the transient beam energy numerically for the above cases. We also propose the actual compensation method.

• H.R. Yang, M.-H. Cho, S.D. Jang, S.H. Kim, W. Namkung, S.J. Park
  POSTECH, Pohang, Kyungbuk
• K.H. Chung, K. Lee
  KAPRA, Cheorwon
• J.-S. Oh
  NFRI, Daejon

A C-band standing-wave electron linac for a compact X-ray source is now being commissioned at ACEP (Advanced Center for Electron-beam Processing in Cheorwon, Korea). It is designed to produce 4-MeV electron beam with pulsed 50-mA, using a 5-GHz RF power generated by a magnetron with pulsed 1.5 MW and average 1.2 kW. The accelerating structure is a bi-periodic and on-axis-coupled one operated with π/2-mode standing-waves. It is consisted of 3 bunching cells, 6 accelerating cells and a coupling cell. As a result of measurements, the beam energy is almost 4 MeV. In this paper, we present the design details and the commissioning status.

• K. Lee, S. Hirai, M. Uesaka
  The University of Tokyo, Nuclear Professional School, Ibaraki-ken
• E. Hashimoto
  JAEA, Ibaraki-ken
• T. Natsui
  UTNL, Ibaraki

950 keV X-band Linac has the merits of compact system, and it does not need the radiation safety manager on-site in the public space. Therefore the system we have developed is suitable for the more safe circumstance in airport. Dual energy X-ray concept is introduced for material recognition with Linac these days, because it produce high energy X-ray which is available in case the target is thick and high atomic number material. We suggest two fold scintillator detector concept to induce dual energy X-ray effect. The design of two fold scintillator is decided by MCNP simulation with two scintillator code, CsI and CdWO4. The material recognition is confirmed using aluminium, iron and lead metal in conditions such as various thicknesses and containers.