Development of linear position-sensitive neutron detector for modern neutron sources

Prerequisities

In the frame of creation of scientific instruments at the PIK research reactor complex, a new thermal neutron powder multi-detector diffractometer D3 is being developed for researches at the field of condensed matter under high pressures. An assembly of 126 (6×16) linear position-sensitive helium detectors with charge division is proposed to register the scattered neutrons at D3. Required parameters of the helium-filled tubes are: length 561 mm, diameter 8 mm, spatial resolution along the anode should be at least 3 mm.

Linear position-sensitive thermal neutron detectors (LPSD) operating on the principle of charge division are reliable, time-tested devices. However, high intensity of neutron beams at new modern sources can lead to overloads of existing models and dramatic reduction of spatial resolution. Degradation of the anode wire at high neutron fluxes can also lead to a drastic reduction in the service life of the detectors.

In order to solve this problem, the cooperation of the National Research Center “Kurchatov Institute” – PNPI together with LLC “Kvant Group”, and the Joint Institute for Nuclear Research initiated development of LPSDs and electronic systems capable of working on modern neutron sources.

Current activities of neutron detector development department of National Research Center “Kurchatov Institute” – PNPI and LLC “Quantum Group “

  • Design of neutron instruments at PIK research reactor
  • Research and development of neutron detector systems in accord to the request of PIK research reactor – Supported by Ministry of science of Russian Federation. Collaboration with JINR.
  • Manufacturing of the detectors for neutron instruments – Founded by Ministry of science of Russian Federation. Detectors are to be supplied to PIK reactor in 2022-2024.

Position-sensitive counters

Position-sensitive counters

Developed counters parameters

  • Aperture: 1000*8/600*8 mm2
  • Total pressure: 12.5 bar
  • Efficiency: up to 75% for neutrons with 0.2 nm wavelength.
  • Anode resistivity – 10 kOhm/m

Position-sensitive counterstests

Test scheme 1

Test counter parameters

  • Aperture: 600*8 mm2
  • High voltage: 1400 V

Tests performed in collaboration with JINR and NRC “Kurchatov institute”

Resolution ≥ 2 mm

Test scheme 2

Width of the circular slit = 8 mm

HV = 1200 V, Resolution ≥ 8 mm

Total peak width ≥ 11 mm

Test scheme 3

Width of the circular slit = 8 mm

HV = 1400 V, Resolution ≥ 1 mm

Conclusions

The cooperation of the National Research Center “Kurchatov Institute” – PNPI, LLC “Kvant Group” and the Joint Institute for Nuclear Research results in development of LPSD with  parameters competitive worldwide. The electronic systems capable of working on modern neutron sources are under final stage of development. The first results of this work demonstrate the capability of cooperation to solve the actual problems in the field of neutron detector development.

As a result of the reported work the linear position-sensitive detectors with length from 100 mm up to 4000 mm and diameter from 8 to 25.4 mm are developed with spatial resolution up to 2 mm along the tube.

Kvant group