Speaker
Hongjie Liu
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P4.2003.pdf
Fast Neutron Detection in Super-intense γ Radiation
Hongjie Liu 1,2, Yuqiu Gu1,2, Bo Cui1, Leifeng Cao1,2
1
Research Center of Laser Fusion, CAEP, Mianyang, China
2
Science and technology on plasma physics laboratory, Mianyang, China
Scintillator detectors in inertial confinement fusion experiments are predominantly used to
measure neutron yield and ion temperature of the primary fusion reactions. The detection of
neutrons in fast-ignition experiments is very challenging since it requires the neutron detection
system to recover within 100 ns from a high background orders of magnitude stronger than the
signal of interest. Liquid scintillator with different compositions was investigated. We present
several designs of liquid scintillator using the Geant4 Code and the X-Lab Code. Our liquid
scintillator is based on PPO, dissolved in xylene and enriched with molecular O2. The detector
consists of a 2-3 liters volume of liquid scintillator coupled to a gated MCP. The gating
performance under high-intensityγrays was experimentally checked. The typical flight time
spectrum of the neutrons from (p,n) reaction driven by a PW laser is shown in Fig.1. The
neutron yield in the fast ignition experiments on Shenguang-II laser facility was successfully
measured using this detector. Our neutron detection system could suppress the background
signal and eliminate the afterglow present in conventional plastic scintillators.
Fig. 1 Neutron flight time spectrum obtained in PW laser
References:
1. Abe Y. Hosoda H. Arikawa Y, et. al, Characterizing a fast-response, low-afterglow liquid scintillator for
neutron time-of-flight diagnostics in fast ignition experiments, Review Scientific Instruments, 85 (2014).
2. Stoeckl C, Cruz M, Glebov V.Y, et.al, A gated liquid-scintillator-based neutron detector for fast-ignitor
experiments and down-scattered neutron measurements. Review Scientific Instruments, 81 (2010), 10D302
