Heading for brighter and faster β-Ga2O3 scintillator crystals

Czochralski-grown β-Ga2O3 and β-Ga2O3:Si crystals with the free electron concentrations between 2.5·1016 and 4.3·1018 cm−3 have been characterized by means of pulse height and scintillation time profile measurements in order to assess their basic scintillation properties. At room temperature, with increasing free electron concentration in the studied range, the scintillation yields decrease from 8920 to 1930 ph/MeV, while the mean scintillation decay times pare down from 989 to 61 ns. However, when the brightest β-Ga2O3 sample is cooled down below 100 K, its scintillation yield exceeds 20000 ph/MeV

New perspectives for undoped CaF2 scintillator as a threshold activation neutron detector

In this paper we present the prompt photofission neutron detection performance of undoped CaF2 scintillator using Threshold Activation Detection (TAD). The study is carried out in the frame of C-BORD Horizon 2020 project, during which an efficient toolbox for high volume freight non-intrusive inspection (NII) is under development. Technologies for radiation monitoring are the part of the project. Particularly, detection of various radiological threats on country borders plays an important significant role in Homeland Security applications. Detection of illegal transfer of Special Nuclear Material (SNM) - 235U, 233U and 239Pu - is particular due to the potential use for production of nuclear weapon as well as radiological dispersal device (RDD) V known also as a "dirty bomb". This technique relies on activation of 19F nuclei in the scintillator medium by fast neutrons and registration of high-energy β particles and γ-rays from the decay of reaction products. The radiation from SNM is detected after irradiation in order to avoid detector blinding. Despite the low 19F(n,α)16N or 19F(n,p)19O reaction cross-section, the method could be a good solution for detection of shielded nuclear material. Results obtained with the CaF2 detector were compared with the previous study done for BaF2 and 3He detector. These experimental results were obtained using 252Cf source and 9 MeV Varian Linatron M9 linear accelerator (LINAC). Finally, performance of the prompt neutron detection system based on CaF2 will be validated at Rotterdam Seaport during field trails in 2018

Surface recombination and space-charge-limited photocurrent-voltage (PC-V) measurements in (Cd,Mn)Te samples. Kinetics of photocurrent (PC)

Photocurrent-voltage characteristic (PC-V) is a method of determining the critical parameter in X-ray and gamma-ray detector plates, i.e., the carrier mobility - lifetime product, mt. We show on the (Cd,Mn)Te samples that the measurement results depend strongly on the surface treatment and the charge space distribution. The PC-V characteristics obtained for hv > Eg and hv ~ Eg indicated that etching with 20% HCl caused an appearance of a significant concentration of very shallow surface traps at the (Cd,Mn)Te sample surface. These traps seriously changed the measurements of PC-V characteristics and PC kinetics. We also noticed a small contribution of holes to photoconductivity in the PC kinetics. The PC-V characteristics measurements for hv > Eg may test the detector plate surface quality.Comment: 16 pages, 13 figure

Characterization of some modern scintillators recommended for use on large fusion facilities in γ-ray spectroscopy and tomographic measurements of γ-emission profiles

LaBr3:Ce,CeBr3 and GAGG:Ce scintillators were investigated and the determined characteristics were compared with those obtained for the well-known and widely used CsI:Tl and NaI:Tl crystals. All the detectors were of the same size of 10 × 10 × 5 mm3. The aim of this test study was to single out scintillation detectors most suitable for γ-ray spectrometry and γ-ray emission radial profile measurements in high-temperature plasma experiments. Decay time, energy resolution, non-proportionality and full energy peak detection efficiency ere measured for γ-ray energies up to 1770 keV. Due to their good energy resolution, short decay time and high detection efficiency for MeV gamma rays, LaBr3:Ce and CeBr3 scintillators are proposed as the best candidates for use especially under conditions of high count rates, which are expected in the forthcoming DT experiments

Design of the rapidly relocatable tagged neutron inspection system of the C-BORD project

International audienceWithin the framework of the European H2020 C-BORD project, aiming at improving container inspection technologies, a compact and "Rapidly Relocatable Tagged Neutron Inspection System", called RRTNIS, is being developed taking into account past EURITRACK experience with a portal TNIS, and the latest technologies in terms of associated particle neutron generator and data acquisition electronics. A dedicated shield surrounding the neutron generator has been designed with MCNP6 to limit the size of the restricted area and the count rate on gamma detectors, which are located very close to the generator. This new design with "reflection" detectors only, i.e. in backscattering position, is indeed more efficient to detect suspect items, like explosives or illicit drugs, in bottom regions of the container, compared to EURITRACK detectors which were mainly located above the container. It also allows designing a relocatable system for different inspection sites like seaports, borders, or other checkpoints. Dose and count rate calculations are presented to determine the restricted area and facilitate the design of the data acquisition electronics, respectively

A Distributed Data Acquisition System for the Sensor Network of the TAWARA_RTM Project

This paper describes a distributed Data Acquisition System (DAQ) developed for the TAWARA-RTM project (TAp WAter RAdioactivity Real Time Monitor). The aim is detecting the presence of radioactive contaminants in drinking water; in order to prevent deliberate or accidental threats. Employing a set of detectors, it is possible to detect alpha, beta and gamma radiations, from emitters dissolved in water. The Sensor Network (SN) consists of several heterogeneous nodes controlled by a centralized server. The SN cyber-security is guaranteed in order to protect it from external intrusions and malicious acts. The nodes were installed in different locations, along the water treatment processes, in the waterworks plant supplying the aqueduct of Warsaw, Poland. Embedded computers control the simpler nodes, and are directly connected to the SN. Local-PCs (LPCs) control the more complex nodes that consist signal digitizers acquiring data from several detectors. The DAQ in the LPC is split in several processes communicating with sockets in a local sub-network. Each process is dedicated to a very simple task (e.g. data acquisition, data analysis, hydraulics management) in order to have a flexible and fault-tolerant system. The main SN and the local DAQ networks are separated by data routers to ensure the cyber-security