광다이오드 검출기와 붕소를 이용한 252Cf 방사선원의 중성자 검출 및 Geant4 시뮬레이션: Neutron detection and Geant4 simulation by using a photodiode detector with boron neutron converter

by Kook Hyun Kang (MS Candidate)

Thursday Nov 14, 2013, 4:20 PM → 4:50 PM Asia/Seoul

119호 (제1과학관)

We aim to detect neutrons by using a photodiode detector with neutron converter. The neutron detector can be used for nuclear physics experiment, neutron flux monitoring in reactor, neutron radiography, and nuclear material detection. As an incoming light traverses the photodiode, it produces electron-hole pairs. The neutron has low cross section for silicon and a neutron converter is needed to make charged particles by the nuclear capture process. We use 10B as a neutron converter. We use 252Cf radioactive source as the neutron source, which emits neutrons of 2.1 MeV on average. The neutron capture cross section of a converter is inversely proportional to neutron energy and the polyethylene (PE) is used as a moderator to provide the thermal neutron. The photodiode detects the alpha particles from 10B(n, α)7Li reaction. A thick lead is used to shield gamma rays of 1.0 MeV from 252Cf and the reaction. We measure alpha energy spectrum and compare it with Geant4 Monte Carlo simulation. We check the thermal neutron capture and compare simulation and experiment of neutron detection by using Geant4. We plan to use enriched 10B to increase reaction cross in near future.

Thesis Advisor: Prof. Hwanbae Park