The applicability of LaBr3:Ce detectors for high count rate γ-ray spectroscopy is investigated. A 3"x3" LaBr3:Ce detector is used in a test setup with radioactive sources to study the dependence of energy resolution and photo peak efficiency on the overall count rate in the detector. Digitized traces were recorded using a 500 MHz FADC and analysed with digital signal processing methods. In addition to standard techniques a pile-up correction method is applied to the data in order to further improve the high-rate capabilities and to reduce the losses in efficiency due to signal pile-up. It is shown, that γ-ray spectroscopy can be performed with high resolution at count rates even above 1 MHz and that the performance can be enhanced in the region between 500 kHz and 10 MHz by using pile-up correction techniques.
A simple, self-contained, thermo-electrically cooled SiPM system is presented which cools a SiPM array to -20 C. The array views a NaI scintillator through a 75 mm diameter glass window. Waste heat is removed with a large heat sink and AC fans. Above 40 keV in an air-coupled 2" x 2" NaI scintillator, the SiPM dark count rate was reduced by a factor of about 1000 when cooled. Spectroscopic performance when cooled was very similar to a PMT tested in the same setup, and adequate for nuclear spectrsocopy above 25 keV. Originally, water cooling was used but it was replaced by air cooling which is m…
A newly developed segmented YSO scintillator detector was implemented for the first time at the RI-beam Factory at RIKEN Nishina Center as an implantation-decay counter. The results from the experiment demonstrate that the detector is a viable alternative to conventional silicon-strip detectors with its good timing resolution and high detection efficiency for ${\rm β}$ particles. A Position-Sensitive Photo-Multiplier Tube (PSPMT) is coupled with a $48\times48$ segmented YSO crystal. To demonstrate its capabilities, a known short-lived isomer in $^{76}$Ni and the ${\rm β}$ decay of $^{74}$Co we…
We describe the design, construction and performance of the upgraded DO muon system for Run II of the Fermilab Tevatron collider. Significant improvements have been made to the major subsystems of the DO muon detector: trigger scintillation counters, tracking detectors, and electronics. The Run II central muon detector has a new scintillation counter system inside the iron toroid and an improved scintillation counter system outside the iron toroid. In the forward region, new scintillation counter and tracking systems have been installed. Extensive shielding has been added in the forward region…
Upgrade of the POLDI diffractometer with a ZnS(Ag)/6LiF scintillation detector read out with WLS fibers coupled to SiPMs
Paul Scherrer研究所（PSI）正在开发一种基于ZnS（Ag）/6LiF闪烁体、波长移动光纤（WLS）和硅光电倍增器（SiPM）的热中子探测器，用于升级POLDI仪器（一种脉冲重叠衍射仪）。检测器的设计概述，并在一个单通道原型上进行测量。正在开发一种基于光子计数方法的创新信号处理系统。它的工作原理进行了描述，其性能进行评估的基础上的蒙特卡罗模拟。
Low counting experiments (search for double $β$ decay and dark matter particles, measurements of neutrino fluxes from different sources, search for hypothetical nuclear and subnuclear processes, low background $α$, $β$, $γ$ spectrometry) require extremely low background of a detector. Scintillators are widely used to search for rare events both as conventional scintillation detectors and as cryogenic scintillating bolometers. Radioactive contamination of a scintillation material plays a key role to reach low level of background. Origin and nature of radioactive contamination of scintillators, …
A large-area Multi-Pixel Photon Counter (MPPC) sensitive to vacuum ultra violet (VUV) light has been developed for the liquid xenon (LXe) scintillation detector of the MEG II experiment. The LXe detector is designed to detect the 52.8\,MeV photon from the lepton flavour violating decay $μ^+ \to \mathrm{e}^+ γ$ and is based on $900\,\ell$ LXe with a highly granular scintillation readout by 4092 VUV-MPPCs with an active area of $139\,\mathrm{mm}^2$ each, totalling $0.57\,\mathrm{m}^2$. The VUV-MPPC shows an excellent performance in LXe, which includes a high photon detection efficiency (PDE) up …
We measured signals of low amplitudes originating from cosmic rays, using two rectangular-block scintillation detectors at various positions. The signals were analyzed by a slightly modified signal analyzer from project 'MuonLab', designed to measure the lifetime and velocity of muons from cosmic radiation in high school education. In our experiment we focused on the possibilities of the apparatus to measure the time difference 'deltatime (DT)' between signals in two scintillation detectors and the signal amplitude 'pulse height (PH)' of the signal in one detector. We performed measurements in…
DANSS is a one cubic meter plastic scintillator detector with a primary goal of the sterile neutrino searches at a commercial nuclear reactor. Due to its highly advantageous location, fine segmentation and ability to change the distance to the neutrino production origin DANSS is ahead of many similar experiments around the world in terms of the counting rate, signal to background ratio and sterile neutrino exclusion regions. Yet a moderate energy resolution of the detector prevents the further progress in the physics program. The main challenge of the planned upgrade is to achieve the energy r…
A novel data-processing method was developed to facilitate scintillation detector characterization. Combined with fan-beam calibration, this method can be used to quickly and conveniently calibrate gamma-ray detectors for SPECT, PET, homeland security or astronomy. Compared with traditional calibration methods, this new technique can accurately calibrate a photon-counting detector, including DOI information, with greatly reduced time. The enabling part of this technique is fan-beam scanning combined with a data-processing strategy called the common-data subset (CDS) method, which was used to s…
Scintillation Properties of CsPbBr3 Nanocrystals Prepared by Ligand-Assisted Reprecipitation and Dual Effect of Polyacrylate Encapsulation toward Scalable Ultrafast Radiation Detectors
Secondary scintillation yield of Xenon with sub-percent levels of CO2 additive: efficiently reducing electron diffusion in HPXe optical TPCs for rare-event detection
The spherical proportional counter is a large volume gaseous detector which finds application in several fields, including direct Dark Matter searches. When the detector is filled with nitrogen it becomes an effective neutron spectrometer thanks to the $^{14}$N(n,$\mathrmα$)$^{11}$B and $^{14}$N(n,p)$^{14}$C reactions. Nitrogen, however, is a challenging operating gas for proportional counters and requires a high electric field strength to gas pressure ratio. Benefiting from the latest advances in spherical proportional counter instrumentation and simulation techniques, we report first neutron…
在CLEAN（Cryogenic Low Energy Astrophysics with Noble Gases）中，如果能够以高精度确定电离辐射事件的位置，则背景鉴别是可能的。CLEAN是一种建议的中微子和暗物质探测器。我们模拟电离辐射事件，产生多个闪烁光子内充满液体氖的球形检测体积。我们估计一个特定的电离辐射事件的径向位置的基础上观察到的计数数据对应于该事件。计数数据由安装在检测体积的球形边界处的检测器收集。我们忽略吸收，但考虑瑞利散射。为了解释闪烁光的波长漂移，我们假设光子在探测器处被吸收并重新发射。在这里，我们开发了空间极大似然方法的事件重建，并研究其性能在计算机模拟实验。我们还研究了一种基于观测计数数据质心的方法。我们根据训练数据校准我们的估计。
To increase the light yield of a liquid Ar (LAr) detector, we optimized the evaporation technique of tetraphenyl butadiene (TPB) on the detector surface and tested the operability of a silicon photomultiplier (SiPM), namely, the multi-pixel photon counter with through-silicon-via (TSV-MPPC, Hamamatsu Photonics K.K.) at LAr temperature. TPB converts the LAr scintillations (vacuum ultraviolet light) to visible light, which can be detected by high-sensitivity photosensors. Because the light yield depends on the deposition mass of TPB on the inner surface of the detector, we constructed a well-con…
Detector Performance and Dark Matter Sensitivity of CYGNO with HFO-1234ze Gas Admixtures
Istituto Nazionale di Fisica Nucleare（意大利国家核物理研究所罗马第三分部）；Sezione di Roma Tre（意大利国家核物理研究所大萨索国家实验室）；Istituto Nazionale di Fisica Nucleare（意大利国家新能源与可再生能源研究中心弗拉斯卡蒂中心）；Laboratori Nazionali del Gran Sasso（意大利国家核物理研究所罗马分部）；ENEA Centro Ricerche Frascati；Istituto Nazionale di Fisica Nucleare；Sezione di Roma
Precise in-situ measurements of the neutron flux in underground laboratories is crucial for direct dark matter searches, as neutron induced backgrounds can mimic the typical dark matter signal. The development of a novel neutron spectroscopy technique using Spherical Proportional Counters is investigated. The detector is operated with nitrogen and is sensitive to both fast and thermal neutrons through the $^{14}$N(n, $α$)$^{11}$B and $^{14}$N(n, p)$^{14}$C reactions. This method holds potential to be a safe, inexpensive, effective, and reliable alternative to $^3$He-based detectors. Measuremen…
Neutron spectroscopy is an invaluable tool for many scientific and industrial applications, including underground Dark Matter searches. Neutron-induced backgrounds produced by cosmic ray muons and the cavern radioactivity can mimic the expected Dark Matter signal. However, existing neutron detection methods have several drawbacks and limitations, thus measurements remain elusive. A promising new approach to neutron spectroscopy is the use of a nitrogen-filled spherical proportional counter that exploits the $^{14}$N(n,$α$)$^{11}$B and $^{14}$N(n, p)$^{14}$C reactions. This is a safe, inexpensi…
A Neural Network Approach to Multi-radionuclide TDCR Beta Spectroscopy
Institute of Frontier and Interdisciplinary Science, Shandong University（前沿与交叉科学研究院，山东大学）；Key Laboratory of Particle Physics and Particle Irradiation, Ministry of Education, Shandong University（粒子物理与粒子辐照重点实验室，教育部，山东大学）
