A MeV Neutron Bunching System in KIGAM Tandem Accelerator

Gi Dong Kim, Wan Hong, Hyung Joo Woo, Han Woo Choi (KIGAM)
Jong Hwa Jang (KAERI)

The nuclear data project as one of the nation-wide nuclear R&D programs was launched KAERI in 1999. Its main goals are to establish a nuclear data system, to construct the infrastructure for nuclear data production and evaluation, and to develop a highly reliable nuclear data system. In KIGAM, neutron cross section in energy range from 1 MeV to 2 MeV, which is interest in the field of fusion reactor materials, has been measured.
The 3T(p,n)3He reaction is available to produce fast neutrons, and the target of this reaction is a thin film of TiT with an areal density of about 300 ug/cm2. A neutron pulsing and bunching system of KIGAM 1.7 MV Tandem accelerator has been designed and is now under fabrication for the measurement of MeV neutron capture cross sections.
The pulsed beam is obtained by a combination of deflector electrode and slit. Then bunched beam is obtained by the three stage electrodes, on which double bunching principle is applied. The specification of neutron bunching beam is designed to be that the repetition rate is 8 MHz, the width is about 2 ns, and duty factor is about 20 %. A 45 degree bending magnet of C type and power supply units of beam bunching system are being fabricated to guide the charged particle beam to a new neutron experimental room. A beam profile monitor, slits, faraday cup and magnetic quadrupole doublet lens are planned to be positioned to confirm an optimum pulsed beam shape. The beam dynamics for each optical component was calculated by e beam transport program, and a program was made to show the bunching profile and compression ratio of proton beam. Applied alternative voltage, size, and intervals of electrodes, and slit size were determined by a simulation with the home-made program and calculation with Superfish code.

제15회 탄템 가속기 및 그 주변기술연구회 (2002.6, Tsuruga, Japan)