Detecting fast and thermal neutrons with a boron loaded liquid scintillator, EJ-339A

Large Scale BN-perovskite Nanocomposite Aerogel Scintillator for Thermal Neutron Detection

State-of-the-art thermal neutron scintillation detectors rely on rare isotopes for neutron capture, lack stability and scalability of solid-state scintillation devices, and poorly discriminate between the neutron and gamma rays. The boron nitride (BN)-CsPbBr₃ perovskite nanocomposite aerogel scintillator enables discriminative detection of thermal neutrons, features the largest known size (9 cm across), the lowest density (0.17 g cm^-3 ) among the existing scintillation materials, high BN (50%) perovskite (1%) contents, high optical transparency (85%), and excellent radiation stability. The new detection mechanism relies on thermal neutron capture by ¹⁰ B and effective energy transfer from the charged particles to visible-range scintillation photons between the densely packed BN and CsPbBr₃ nanocrystals. Low density minimizes the gamma ray response. The neutrons and gamma rays are discriminated by complete decoupling of the respective single pulses in time and intensity. These outcomes open new avenues for neutron detection in resource exploration, clean energy, environmental, aerospace, and homeland security applications.

Novel flexible and conformable composite neutron scintillator based on fully enriched lithium tetraborate

Thermal neutron detection is a key subject for nuclear physics research and also in a wide variety of applications from homeland security to nuclear medicine. In this work, it is proposed a novel flexible and conformable composite thermal neutron scintillator based on a fully enriched Lithium Tetraborate preparation ([Formula: see text]Li[Formula: see text]B[Formula: see text]O[Formula: see text]) combined with a phosphorescent inorganic scintillator powder (ZnS:Ag), and is then distributed into a polydimethylsiloxane matrix. The proposed scintillator shows a good neutron detection efficiency (max. [Formula: see text] 57% with respect to the commercial EJ-420), an average light output of [Formula: see text] 9000 ph/neutron-capture, a remarkable insensitivity to [Formula: see text]-rays (Gamma Rejection Ratio <10[Formula: see text]), and an extraordinary flexibility, so as to reach extremely small curvature radii, down to 1.5 mm, with no signs of cracking or tearing. Its characteristics make it suitable to be employed in scenarios where non-standard geometries are needed, for example, to optimize the detector performance and/or maximize the detection efficiency. Finally, the response of a hybrid detector made of a plastic scintillator, wrapped with the proposed scintillator, coupled to a silicon photomultiplier array is described, and the excellent discrimination between [Formula: see text]-rays, fast and thermal neutrons resulting from data processing is demonstrated.

Novel neutron detector assembly based on SiPM readout to be coupled with the Active Target for SPES

The Active Target ATS (Active Target for SPES) is a new time-projection chamber designed for reaction and decay studies with nuclei far from stability. The physics cases for the new-generation active target are related to the ongoing developments of facilities for radioactive ion beams. Thanks to its flexibility, this instrument will be capable of taking advantage of the most exotic beams which will become available at the SPES facility under construction at the Legnaro National Laboratories in Italy. Particular attention will be also paid to couple it with ancillary detectors, for both charged and neutral (gamma and neutrons) particles. In particular, in this work, we will focus the attention on the neutron ancillary detectors. The proposed prototype is a compact device able to discriminate, by performing pulse shape analysis, between neutrons and gamma. The device take advantage of recent improvements in silicon photomultiplier (SiPM) technology and the development of new plastic scintillators exhibiting neutron/gamma discrimination capability. Our work is focused on the read-out with silicon photomultipliers arrays of EJ-276 (and its old version EJ-299) and EJ-276G scintillators of several sizes (ranging from 20 mm to 50 mm diameter). Moreover, we will show the comparison of discrimination performances between SiPM and standard photomultiplier read-out configurations.