Speaker
Igor Chuprakov
(JINR,FLNP)
Description
This paper presents a position-sensitive detection method for fast neutrons by proton recoil in a plastic scintillator. The detector consists of a plastic scintillator with silicon photomultiplier readout and pixel detector Timepix. As a known plastic scintillators are hydrogen-rich materials adopted as neutron to proton convertors by elastic (n, p) scattering. Silicon pixel detector Timepix is used for position-sensitive detection of recoil protons which exit the plastic scintillator. Scintillation light is read out using micropixel avalanche photodiode of type MAPD-3NK from Zecotek Photonics Inc. MAPD-3NK allows to measure the energy loss by protons in the plastic scintillator and to trigger Timepix detector.
Timepix detector is a silicon based hybrid pixel detector which allows obtaining information from each pixel. The detector consists of 256*256 square pixels (55 µm) with pitch size of 55 µm. The active area and thickness of the detector is about 1.96 mm2 and 300 µm, respectively.
Micropixel avalanche photodiode of type MAPD-3NK is one of silicon based alternatives to common vacuum photomultipliers. MAPD-3NK consists of deeply burned pixels connected in parallel and operating in the Geiger mode. MAPD-3NK has a total photosensitive area of 3.7*3.7 mm2 and 10000 pixels per mm2. Operating voltage is about 90 V for this photodiode.
Experiments have been carried out with 239Pu-Be radioisotopic neutron source and monoenergetic neutrons from the reaction D(d, n)3He on the EG-5 Van de Graaff accelerator, FLNP, JINR.
Primary author
Igor Chuprakov
(JINR,FLNP)
