Scientists of the Joint Institute for Nuclear Research developed a neutron/gamma detector based on a micropixel avalanche photodiode (MAPD) and a plastic scintillator that monitors the status of the accelerator-driven Intense Resonance Neutron Source (IREN) Facility by measuring the neutron/gamma intensity in the target hall. The detector was engineered by specialists from the Laboratory of Neutron Physics and the Laboratory of High Energy Physics at JINR in cooperation with colleagues from research centres of Azerbaijan, the Czech Republic, and Kazakhstan.

The electronics of the neutron/gamma detector were designed and developed by an international team of scientists. The size of the plastic scintillator was selected to be 3.7 × 3.7 × 30 mm3 due to the sensitive area of the MAPD.

A top view of electronic read-out and MAPD based plastic scintillator

The experimental results demonstrated a dependence between the count rate of the detector and the frequency of the accelerator. The detector is sensitive to intermediate and fast neutrons. The minimum detectable energy was determined to be 200 keV using a Cs-137 point gamma source. The maximum counting rate of the detector from TTL out is about 2.2·106 counts/sec, but for analogue output, it is about 2·107 counts/sec. The detector can not allow discriminating neutrons and gamma rays by the charge integration method.

The full text detailing the results was published in Nuclear Engineering and Technology in May 2024. Authors: Sabuhi Nuruyev, Daniyar Berikov, Ramil Akbarov, Gadir Ahmadov, Farid Ahmadov, Azer Sadigov, Michael Holík, Jalal Naghiyev, Afag Madadzada, and Konstantin Udovichenko.