Tests of Various Scintillator Detectors in Selected Mono-Energetic Neutron Beams

In this paper we study quality of three types of organic scintillators stilbene, p-terphenyl and EJ-299-33. We used monoenergetic neutron fields with a wide range of neutron energies in PTB Braunschweig. All the tests were carried out with NGA-01 spectrometer. The results of the measurements are evaluated spectra from the spectrometer. We discuss the quality of each scintillator, such as the FWHM of the peaks.

Polydatin Attenuates 14.1 MeV Neutron-Induced Injuries via Regulating the Apoptosis and Antioxidative Pathways and Improving the Hematopoiesis of Mice

With more powerful penetrability and ionizing capability, high energetic neutron radiation (HENR) often poses greater threats than photon radiation, especially on such occasions as nuclear bomb exposure, nuclear accidents, aerospace conduction, and neutron-based radiotherapy. Therefore, there emerges an urgent unmet demand in exploring highly efficient radioprotectants against HENR. In the present study, high-throughput 14.1 MeV neutrons were generated by the high-intensity D-T fusion neutron generator (HINEG) and succeeded in establishing the acute radiation syndrome (ARS) mouse model induced by HENR. A series of preclinical studies, including morphopathological assessment, flow cytometry, peripheral complete blood, and bone marrow karyocyte counting, were applied showing much more serious detriments of HENR than the photon radiation. In specific, it was indicated that surviving fraction of polydatin- (PD-) treated mice could appreciably increase to up to 100% when they were exposed to HENR. Moreover, polydatin contributed much in alleviating the HENR-induced mouse body weight loss, spleen and testis indexes decrease, and the microstructure alterations of both the spleen and the bone marrow. Furthermore, we found that the HENR-damaged hematopoiesis was greatly prevented by PD treatment in such aspects as bone marrow hemocytogenesis, splenocytes balancing, or even the peripheral blood cellularity. The additional IHC investigations revealed that PD could exert potent hematopoiesis-promoting effects against HENR via suppressing apoptosis and promoting the antioxidative enzymes such as HO-1.

Cross section determination for TAD materials in quasi mono-energetic neutron spectrum from p(Li) reaction

Threshold activation detectors (TAD) are of great importance for a determination of neutron energy spectra and flux density. For different sources, it is necessary to choose the right combination of materials that cover the estimated spectra. Several different materials were irradiated in a quasi-monoenergetic neutron field with 29.1 MeV peak neutrons energy in the CANAM facility. Neutrons were produced in p + Li-7 reaction in a thin target and the foils were situated in the proton beam axis and close geometry to the Li target. The integral number of protons was established from accelerator telemetry and lithium target activation measurements after the experiment. During the experiment, one long irradiation was done for following foils: Al, Au, Bi, Co, Cu, Fe, In, Mn, Pb, Ta, V, Y and four short irradiations for foils: Cu, Fe, In, Ta, V, W, Y. The foils were irradiated in a sandwich configuration, sorted by cross-section where the materials with higher cross-section were placed in the back of the sandwich. Neutrons produced in the p + Li-7 reaction have a quasi mono-energetic spectrum which provides a suitable basis for cross-section determination. Experimental results were calculated for (n,xn), (n,p) and (n,α) reactions via the dosimetry foils activation method including a gamma-ray spectroscopy method. Several important spectroscopic corrections have to be applied to increase the accuracy of the obtained results, including neutron background suppression. Experimental data will be submitted to the EXFOR database.

Investigation of the neutron-gamma ray discrimination performance at low neutron energy of a solution-grown stilbene scintillator

The results of experiments performed with a Ø25 x 25 mm solution-grown stilbene crystal in mono-energetic neutron fields in the 80-to-230 keV energy range are presented. The goal of the measurements, performed at the AMANDE facility, was to explore the capabilities of this organic scintillator to measure neutrons at the lowest possible energy with good pulse shape discrimination (PSD). The time of flight (TOF) technique was used in order to help with the neutron-gamma discrimination. The data are collected via a programmable digital acquisition (DAQ) system CAEN DT7530 using the software CoMPASS with the charge comparison method (CCM). The data are analysed using post-processing codes developed in the ROOT environment. The results show that the stilbene detector has discrimination capabilities for energies as low as 80 keV.

Monte-Carlo modeling and simulation of neutrons detection process using Boron-10

The interaction of a mono-energetic neutron beam with a target layer of Boron-10 is studied to characterize the behavior of neutrons and produced charged particles inside the layer. The detection system is modeled through a Monte-Carlo simulation. The quality of the simulation method and controlling parameters is assessed with the response function. The Von Neumann rejection sampling method is used to model the interaction process. The obtained results show high agreement with previous results.