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• CeBr 3 and NaI (Tl) scintillators characterized with array of Silicon Photomultipliers. • Energy resolution improves with lower shaping time and higher SiPM over-voltage. • Temperature dependency of gain of SiPM array: ∼−0.81 %/°C for overvoltage of 2.5 Volts. • Temperature dependency of light yield for CeBr 3 : ∼−0.27 %/°C for −31 °C to +26 °C. • Temperature dependency of light yield for NaI (Tl): ∼+0.5 %/°C for −31 °C to +26 °C. Interaction of X-rays with a scintillation detector produces optical photons in the visible range. The spectral and spatial information of the X-ray can be derived by detecting these output photons using a Silicon Photomultiplier (SiPM). Two types of detector modules: CeBr 3 and NaI (Tl), coupled with an array of SiPM are presented here, which are being developed for the future space exploration programs. The development of the front end electronics (FEE) for the charge readout from SiPM for X-ray spectrometer application is presented here which is characterized for SiPM's over-voltages and shaping amplifier's time constant. In this article, both the detector modules are subjected to a wide temperature range to establish a relationship of the SiPM's gain, energy resolution and scintillators' output photon yield with ambient temperature. The test results show that energy resolution improves with higher over-voltage of SiPM and also with lower operating temperature. The gain of the SiPM array shows negative temperature dependence of ∼−0.81 %/°C for an over-voltage of 2.5 Volts. To derive the temperature dependency of scintillators' output photons, gain of the SiPM array was made constant by operating it at a fixed over-voltage for a wide temperature range. With the constant gain of SiPM, CeBr 3 scintillator shows negative temperature coefficient of ∼−0.27 %/°C and NaI (Tl) shows positive temperature coefficient of ∼+0.5 %/°C for the light output in the temperature range of −31 °C to +26 °C. [ABSTRACT FROM AUTHOR]

A new scintillator based fast-ion loss detector (FILD) system has been designed for the Wendelstein 7-X (W7-X) stellarator. The mechanical design of the system is presented here along with engineering analyses of the system. This includes an assessment of the structural loads which also considers electromagnetic forces calculated for possible disruption scenarios as well as a mode frequency analysis of the system. Furthermore, an analysis of the thermal characteristics of the actively cooled probe head under prescribed steady state and transient heat loads is presented. Finally, the optical relay system is described and its properties used to forward model synthetic camera signals using the FILDSIM code and based on theoretical fast-ion losses incident on the probe head calculated using the ASCOT5 code. [ABSTRACT FROM AUTHOR]

This article presents a physics-informed deep learning method for the quantitative estimation of the spatial coordinates of gamma interactions within a monolithic scintillator, with a focus on Positron Emission Tomography (PET) imaging. A Density Neural Network approach is designed to estimate the 2-dimensional gamma photon interaction coordinates in a fast lead tungstate (PbWO 4) monolithic scintillator detector. We introduce a custom loss function to estimate the inherent uncertainties associated with the reconstruction process and to incorporate the physical constraints of the detector. This unique combination allows for more robust and reliable position estimations and the obtained results demonstrate the effectiveness of the proposed approach and highlights the significant benefits of the uncertainties estimation. We discuss its potential impact on improving PET imaging quality and show how the results can be used to improve the exploitation of the model, to bring benefits to the application and how to evaluate the validity of the given prediction and the associated uncertainties. Importantly, our proposed methodology extends beyond this specific use case, as it can be generalized to other applications beyond PET imaging. [ABSTRACT FROM AUTHOR]

RADMON is a small radiation monitor designed and assembled by students of University of Turku and University of Helsinki. It is flown on-board Aalto-1, a 3-unit CubeSat in low Earth orbit at about 500 km altitude. The detector unit of the instrument consists of two detectors, a Si solid-state detector and a CsI(Tl) scintillator, and utilizes the ΔE-E technique to determine the total energy and species of each particle hitting the detector. We present the results of the on-ground and in-flight calibration campaigns of the instrument, as well as the characterization of its response through extensive simulations within the Geant4 framework. The overall energy calibration margin achieved is about 5%. The full instrument response to protons and electrons is presented and the issue of proton contamination of the electron channels is quantified and discussed. [ABSTRACT FROM AUTHOR]

In this paper, the goals and scientific tasks of the space experiment "High Energy Rays Observatory" (HERO) are established. The preliminary design of the scientific equipment is presented, the characteristic features of which are its high geometric factor (up to ∼20 m2 sr) and adequate energy measurement resolution (20–30% or better, depending on the type of components). The ionisation tungsten-scintillator calorimeter is used for energy measurement. The total calorimeter weight is equal to 12 tons. The technical characteristics of the equipment permit the direct study of cosmic rays in a wide energy range, including the unexplored region of 1015–1016 eV. The current status of the space experiment is discussed. Currently, the HERO project is in its pre-R&D phase. The launch of the satellite is planned for between 2025 and 2030. [ABSTRACT FROM AUTHOR]

For the future JET deuterium-tritium (DT) campaigns numerous gamma-ray diagnostics, in particular the JET Gamma-ray Camera (GC) and the JET Gamma-ray Spectrometer (GS), were upgraded in the last few years. The upgrade of GC and GS included replacement of detector modules in order to allow operation at expected high count rate of ∼0.5 Mcps on the scintillator front surface of 506 mm2 for each GC crystal and 7 squared inches for GS as well as to improve energy resolution to equal or better than 5% at gamma-ray energy above 1.1 MeV for both diagnostics. Within the JET4 Enhancements Project, performance of a number of photodetectors including multi-pixel photon counter (MPPC), PIN diode and photomultiplier tube (PMT) connected to scintillators was investigated. Upgraded detector modules are based on fast scintillators with a decay time of about 20 ns, LaBr 3 :Ce and CeBr 3 , coupled to MPPC and PMT for GC and GS, respectively. Results on energy resolution obtained with upgraded diagnostics, already installed at JET, are presented and compared to those collected in laboratory conditions. [ABSTRACT FROM AUTHOR]

Fast-α losses in future fusion power plants are expected to follow the co- and counter-current directions due to the isotropy of the fusion reaction. At the ASDEX Upgrade tokamak, the co-current direction (achieved with positive plasma current and negative toroidal magnetic field) has been extensively studied thanks to an array of five fast-ion loss detectors (FILD). A new fast-ion loss detector compatible with reversed I p /B t (negative plasma current and positive magnetic toroidal field, defining positive as counter-clockwise when the machine is viewed from the top), namely RFILD, has been designed and commissioned to study the behaviour of counter-current fast-ion losses and to expand our knowledge on QH-mode, I-mode, and the L-H transition. The detector is a modified version of the midplane manipulator fast-ion loss detector that features a new probe head orientation and collimator geometry, optimised using the FILDSIM code. A fast CMOS camera is used as a high spatial resolution acquisition system, while an array of photomultipliers (up to 1 MHz) serves as a fast channel. First measurements have been taken in I-mode, QH-mode, L-mode and H-mode with core densities ranging between 4·1019 and 9·1019 m−3, I P between -0.8 and -0.6 MA and B t of 2.5 T approximately. NBI fast-ion losses were observed for the first time in reversed I p /B t , producing high pitch (60 – 80°) losses. ICRH losses in H-minority heating configuration have also been observed in I-mode experiments. These losses correspond to the outer leg of banana particle trajectories. An upgraded double collimator detector design is also presented, that will increase the measurable particle range in future experimental campaigns (co- and counter-current particles simultaneously). Thus, we expand our understanding on the mechanisms behind fast-ion losses at the ASDEX Upgrade tokamak in the reversed I p /B t configuration. [ABSTRACT FROM AUTHOR]

In order to extract neutrino oscillation parameters, long-baseline neutrino oscillation experiments rely on detailed models of neutrino interactions with nuclei. These models constitute an important source of systematic uncertainty, partially because detectors to date have been blind to final state neutrons. Three-dimensional projection scintillator trackers comprise components of the near detectors of the next generation long-baseline neutrino experiments. Due to the good timing resolution and fine granularity, this technology is capable of measuring neutron kinetic energy in neutrino interactions on an event-by-event basis and will provide valuable data for refining neutrino interaction models and ways to reconstruct neutrino energy. Two prototypes have been exposed to the neutron beamline at Los Alamos National Laboratory (LANL) in both 2019 and 2020, with neutron energies between 0 and 800 MeV. In order to demonstrate the capability of neutron detection, the total neutron-scintillator cross section as a function of neutron energy is measured and compared to external measurements. The measured total neutron cross section in scintillator between 98 and 688 MeV is 0.36 ± 0.05 barn. [ABSTRACT FROM AUTHOR]