[3B01-05] Fusion neutronics

[3B02] Overview of the Neutron calibration experiment at LHD and its neutronics analysis

*Takeo Nishitani¹, Kunihiro Ogawa^1,2, Mitsutaka Isobe^1,2, Masaki Osakabe^1,2, Hiroki Kawase², Neng Pu², Jungmin Jo³, MunSeong Cheon⁴, Yuri Kashchuk⁵, Vitaly Krasiknikov⁶ (1. NIFS, 2. SOKENDAI, 3. Seoul National Univ., 4. NFRI, 5. RFDA, 6. IO)

Keywords:LHD, Neutron calibration experiment, Fission chamber, MCNP

Prior to the deuterium experiment of LHD which is planed to start march 2017, the neutron calibration experiment has been carried out for several neutron diagnostics. The toy train rail with O-gage size is installed inside the LHD vacuum vessel. The counts of the neutron diagnostics such as the neutron flux monitor are measured when the toy train with 800 MBq ²⁵²Cf neutron source is rounding inside the LHD vacuum vessel. The detection efficiency of the neutron flux monitor is derived from the count rate for the ring shape neutron source on the magnetic axis. The results agreewell with MCNP calculation using the LHD 3-dimensional model.