A compact and sustainable electronic module for silicon photomultipliers

This article presents the development of a cost-effective and efficient electronic module for silicon photomultipliers (SiPM). The electronic module combines essential functionalities, such as a high voltage power supply, a preamplifier, and a signal comparator, into a compact circuit. A high voltage power supply with a range of 30 to 140 V provides a stable bias voltage with 0.01 V accuracy for the SiPMs, while a preamplifier with 40 gain and 250 MHz bandwidth enables signal amplification necessary to extract weak signals. The comparator converts an analogue signal (higher than 8 mV) into TTL (transistor-transistor logic), which makes it easy to process and analyze with digital devices such as microcontrollers or make it possible to send signals over long distances by a cable. The module has been tested using an LYSO scintillator and a SiPM called a micropixel avalanche photodiode (MAPD). It provides a more effective and efficient solution for reading out signals from SiPMs in a variety of applications, delivering reliable and accurate results in real-time.Comment: an article, 9 pages, 6 figure

Portable neutron/gamma scintillation detector for status monitoring of accelerator-driven neutron source IREN

Accelerator-driven system (ADS) facilities world-wide opens new opportunities for nuclear physics investigations, so that a high flux of neutrons through spallation reactions can be produced at these facilities. It is known that the measurement, continuous monitoring and optimization of the particle accelerator beam intensity are among the most important actions in the operation of such facilities. Considering this point of view, this paper presents a neutron/gamma counter based on a micropixel avalanche photodiode (MAPD) and a plastic scintillator that monitors the status of the accelerator-driven intense resonance neutron source (IREN) facility by measuring the neutron-gamma intensity in the target hall. The electronics of the modular neutron counter has been designed and developed, including a bias voltage source (up to 130 V), a preamplifier (36 gain) and discriminator (>10 mV) circuit. The last product of MAPD (operation voltage- 55 V, PDE- 33 %, total number of pixels- 136900) was used as a photon readout from a plastic scintillator. The sensitive area of MAPD was 3.7*3.7 mm2 and the size of the plastic scintillator 3.7*3.7*30 mm3. The measurement was carried out in the IREN target hall, where it was necessary to monitor not only high neutron fluxes, but also gamma quanta. The experimental results demonstrated a dependence between the count rate of the detector and the frequency of the accelerator, which ranges from 2 to 50 Hz.Comment: 8 pages, 7 figure

Performance of a plastic scintillator developed using styrene monomer polymerization

This paper presents a newly developed plastic scintillator produced in collaboration with Turkiye Energy, Nuclear and Mineral Research Agency (TENMAK). The scintillator is manufactured using thermal polymerization of commercially available styrene monomer. The absorption spectrum of the scintillator exhibited two absorption bands at 225 nm and 340 nm, with an absorption edge observed at 410 nm. The wavelength of the emitted light was measured in the range of 400-800 nm, with a maximum intensity at 427 nm. Monoenergetic electrons from the 137Cs source were used to evaluate the characteristics of the new scintillator, particularly its light yield. As the light readout the MAPD-3NM type silicon photomultiplier array (4 x 4) with an active area of 15 x 15 mm2, assembled using single MAPDs with an active area of 3.7 x 3.7 mm2, was used. The light yield of the scintillator was determined to be 6134 photons/MeV. In addition, the efficiency of the scintillator for gamma rays with an energy of 662 keV was found to be approximately 1.8 %. A CmBe neutron source was employed to evaluate its fast neutron detection performance. However, neutron/gamma discrimination using pulse shape discrimination (charge integration) method was not observed. The results demonstrate the potential of a newly produced plastic scintillator for various applications, particularly in radiation monitoring and detection systems.Comment: 7 pages, 7 figure

ANGULAR DISTRIBUTION OF PROMPT FISSION γ-RAYS

The angular distributions of prompt-fission γ-rays with respect to thedirection of fission fragments in the monochromatic “warm” neutron induced fissionof 235U have been studied. The fragments were detected with low-pressure positionsensitive multi-wire proportional counter and the gamma-rays with a plastic scintillators. The time-of-flight method is used to discriminate prompt neutrons and promptγ-rays of fission. From the measured angular distributions with respect to the directionof the selected fragments, the value of the laboratory anisotropy has been found to be15 % in comparison to the value obtained in the perpendicular direction. The measurements indicate the existence of a significant anisotropy of emission of the γ-rays in theemitting-fragment system, suggesting the presence of significant angular momenta ofthe fragments correlated with the fission axis, which also lead to an enhanced emissionof the γ-rays. Moreover, the article includes a new technique for measuring and correcting the obtained angular distribution, in the case of when plastic scintillators havedifferent threshold levels for detection of γ-rays

Scintillation readout with MAPD array for gamma spectrometer

In this study, we present the gamma-ray detection performance of LYSO, YSO(Ce) and BGO scintillators read out by a 9 ch. micropixel avalanche photodiode (MAPD) array with a high pixel density (PD) and photon detection efficiency (PDE). The array with an active area of 11,5x11,5mm2 was assembled using single MAPDs with an active area of 3,7x3,7mm2. It had a single output signal and was developed for gamma spectroscopy. Breakdown voltage measurements were carried out for each channel, as a result of which the optimal operating voltage for the array was found. The linearity range and energy resolution for each crystal were determined in the energy range from 30 to 1770 keV. The high pixel density of the array allowed to achieve good linearity in the studied energy range

An instrument for measuring T-odd asymmetries in the fission of heavy nuclei

We describe an experimental setup used to measure the T-odd asymmetry effects forprompt fission neutrons andγ-rays in binary fission of some heavy nuclei induced by polarized neu-trons with resonance energy. The overall setup as well as the details of the design and performanceof the key components like fission fragment detectors, neutron andγdetectors, and the electronicsused in the data acquisition and processing system are presented. The experimental setup on beamline POLI of the FRM II reactor (Garching, Germany), as well as the neutron beam characteristics,polarization measurements are described, too

A program for data analysis of rare fission mode processes from neutron-induced and spontaneous fissions

Rare fission mode processes (ternary or quaternary fission) of low-energy and spontaneous fission of heavy nuclei, in which light charged particles are emitted, are the subject of intense experimental and theoretical studies, since these studies can be attributed to one of the main sources of information on the mechanism of nuclear fission. To study these processes, a detection system has been assembled, consisting of three semiconductor ΔE-E telescopes and a silicon detector. In addition, the program has been developed for proceeding experimental data. This paper has been dedicated to the program written on the basis of ROOT software consisting of many scripts to analyze and/or filtrate ternary and quaternary fission particles among different fission events. The program can proceed long collected files in ASCII and binary formats, correlate results from all detectors, give results on particle interaction time, coordinates, particle energy and its types. The performance of the program has been tested to proceed ternary fission data from 252Cf spontaneous fission source

Gamma ray detection performance of newly developed MAPD‑3NM‑II photosensor with LaBr3 (Ce) crystal

This paper presents the gamma-ray detection performance of the newly developed MAPD-3NM-II type SiPM sensor array (4 [Formula: see text] 4) with [Formula: see text](Ce) scintillator. The gamma-ray spectra of various sources have been measured in the energy range from 26 keV up to 1332 keV. The newly developed array based on MAPD-3NM-II sensors proved [Formula: see text] 22% enhancement in energy resolution in comparison to the former MAPD-3NM-I based array. The energy resolution of 662 keV gamma-rays measured by MAPD-3NM-II was 3.3% while clearly surpassing 4.25% resolution of MAPD-3NM-I predecessor. The enhancement is related to the high PDE of the new MAPD-3NM-II. Obtained results show that the new MAPD-3NM-II demonstrated good energy resolution and linearity in the studied energy region. The energy resolution of the new detector developed based on MAPD-3NM-II was better than all previous products of MAPD

A synchronization and data acquisition system for silicon detectors

A dedicated synchronization bus has been developed and integrated into the FITPix COMBO device. It can be used as Timepix read-out (involving back-side-pulse acquisition) or as a simple spectrometer device—Spectrig (when an external single pad sensor is connected, e.g. Δ E detector). The synchronization bus permits the implementation of a system of up to 32 distinct devices running in clock locked mode while the absolute value of the timestamp is distributed to all devices in the system. Any combination of Timepix or spectrometer devices (up to 32) can be connected-up to create a final measurement set-up. The synchronization bus has also been designed to control a trigger signal and busy signal to allow an effective filtration of unpaired events when coincidence measurement is performed. The system has been tested with a Δ E− E telescope consisting of a thin detector and Timepix. The thin detector has been used for Δ E and the Timepix detector for E measurements. The Δ E detector has an area of 10×10 mm2 and a thickness of 12 μm with non-uniformity of 8%. The area and thickness of Timepix are 14×14 mm2 and 300 μm, respectively. The detection system can provide simultaneous information about position, energy, time and type of registered particles with high synchronization accuracy. Test measurements have been carried out with an alpha particle source (Ra-226) in a vacuum and the results of these measurements are presented in this paper

Effect of rotation in the γ -ray emission from 60 meV polarized neutron-induced fission of the U 235 isotope

In the paper we present the results obtained for the effect of rotation (ROT) in the angular distribution of prompt γ rays from the fission of 235U induced by monochromatic polarized “warm” neutrons (En = 60 meV). The polarization vector direction is determined at the target position in order to correctly determine the sign of the measured effect. The asymmetry parameter was found to be equal to Rγ=−(17.3±2.8)×10−5. Moreover, the rotation angle of the fission axis was determined to be equal to 0.069°±0.008° taking into account the fit results of the angular distribution of the prompt fission γ rays. The obtained value and sign of the ROT effect are consistent with the results of the ROT effect obtained for cold neutrons. We describe the experiment, methodology of sign determination, and implications of the result