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The market for SiPMs has grown rapidly in recent years, driven by their increasing use in applications such as medical imaging, nuclear and particle physics. Due to the growing demand, many manufacturers are now offering SiPMs, each of them with unique features and performance characteristics. As a result, it is essential to conduct comparative studies to evaluate and compare the performance of different SiPM arrays. Therefore, this work aims to compare the performance of assembled detectors based on two different SiPM arrays (AdvanSiD-NUV hybrid array ASD-NUV4S-P-4x4TD 17 mm x17 mm and the MPPC Hamamatsu S14161-6050HS-04 25 mm x 25 mm) coupled to two organic scintillators, a liquid scintillator EJ-309 (50 mm diameter x 50 mm thickness) and a plastic scintillator EJ-276G (25 mm diameter x 25 mm thickness). The assessment of the performance was made in terms of their energy resolution, time resolution, and capability to discriminate between γ-rays and fast neutrons. The outcomes show that the Hamamatsu SiPM array performs better for all of the characteristics studied, with the best configuration being when it was coupled to the EJ-309 liquid scintillator, obtaining the lowest energy and time resolutions, (0.108±0.004) and (0.599 ± 0.004) ns respectively, and the highest Figure of Merit (2.04 ± 0.01). A good Figure of Merit value that ensures an effective discrimination between fast neutrons and γ-rays.

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.

Two-dimensional transition metal dichalcogenides (TMDCs) are demonstrated to be appealing semiconductors for optoelectronic applications, thanks to their remarkable properties in the ultraviolet-visible spectral range. Interestingly, TMDCs have not yet been characterized when exposed to x rays, although they would be ideal candidates for optoelectronic applications in this spectral range. They benefit from the high cross section of the constituent heavy atoms, while keeping the absorption very low, due to the ultrathin structure of the film. This encourages the development of photodetectors based on TMDCs for several applications dealing with x rays, such as radioprotection, medical treatments, and diagnosis. Given the atomic thickness of TMDCs, they can be expected to perform well at low dose measurements with minimal perturbation of the radiation beam, which is required for in vivo applications. In this paper, the use of TMDCs as active materials for direct x-ray detection is demonstrated, using a photodetector based on a MoS2 monolayer (1L-MoS2). The detector shows a response to x rays in the range of 101–102 keV, at dose rates as low as fractions of mGy/s. The sensitivity of 1L-MoS2 reaches values in the range of 108–109µC Gy−1 cm−3, overcoming the values reported for most of the organic and inorganic materials. To improve the x-ray photoresponse even further, the 1L-MoS2 was coupled with a polymeric film integrating a scintillator based on terbium-doped gadolinium oxysulfide (Gd2O2S:Tb). The resulting signal was three times larger, enabled by the indirect x ray to visible photoconversion mechanism. This paper might pave the way toward the production of ultrathin real-time dosimeters for in vivo applications. [ABSTRACT FROM AUTHOR]

The fabrication of Avalanche Photodiode (APD) in a standard 0.35-[micro]m CMOS technology is described. The analysis of the noise properties of a pixel based on the proposed photodiode with charge-amplifier readout has shown that it can have an improved noise performance with respect to a standard photodiode-based pixel.

A 64-pixel linear array aimed at 3-D vision applications is implemented in a high-voltage 0.8[micro]m CMOS technology. The detection of the incident light signals is performed using photodiodes biased above breakdown voltage so that an extremely high sensitivity can be achieved exploiting the intrinsic multiplication effect of the avalanche phenomenon. Each 38 x 180-[micro][m.sup.2] pixel includes, besides the single photon avalanche diode, a dedicated read-out circuit for the arrival-time estimation of incident light pulses. To increase the distance measurement resolution a multiple pulse measurement is used, extracting the mean value of the light pulse arrival-time directly in each pixel; this innovative approach dramatically reduces the dead-time of the pixel read-out, allowing a high frame rate imaging to be achieved. The sensor array provides a range map from 2 m to 5 m with a precision better than [+ or -] 0.75% without any external averaging operation. Moreover, with the same chip, we have explored for the first time the implementation of an indirect time-of-flight measurement by operating the proposed active pixel in the photon counting mode. Index Terms--Avalanche photodiode, laser radar, photon counting, range camera, three-dimensional (3-D) image sensor, time of flight (TOF).

We report on n-channel Junction Field Effect Transistors fabricated on high resistivity silicon by means of a specially tailored radiation detector technology. This research activity is being carried out in the framework of a project aiming at the integration of read-out circuits in the same detector substrate. Possible applications are in the field of medical/industrial imaging, space and high energy physics experiments. The pre-existent fabrication process has been modified in several respects to enhance the device noise behavior. In particular, the new process features a high-energy (1 MeV) Boron implantation to obtain a deep p-well which ensures an effective isolation of the transistor from the substrate and a strong modulating effect on the current. Selected results from the experimental characterization of transistors and charge sensitive amplifiers are presented, showing a sizable enhancement in the noise performance with respect to previously available devices. Index Terms--Charge sensitive amplifiers, fabrication technology, junction field effect transistors, noise, radiation detectors.