Possibility of hgh Z material detection by a setup for natural cosmic-ray muon flux measurement

A design is proposed and a resolving power is calculated for a detector that monitors the unauthorized transportation of high Z materials (nuclear materials with Z > 90) using the natural cosmic-ray muon flux. The identification of nuclear materials is based on the strong dependence of the multiple scattering angle on the matter charge upon traversing the matter by cosmic muons. It is proposed that chambers assembled from drift aluminum tubes similar to chambers used in the muon system of the ATLAS detector be used as the coordinate detector for the setup. The calculations show that the proposed variant of the setup makes it possible to detect the presence of nuclear materials with a weight of about 0.5–1 kg and higher in the inspected volume in a measurement time of several minutes.     

A prototype silicon detector system for space cosmic-ray charge measurement

A readout electronics system used for space cosmic-ray charge measurement for multi-channel silicon detectors is introduced in this paper, including performance measurements. A 64-channel charge sensitive ASIC （VA140） from the IDEAS company is used. With its features of low power consumption, low noise, large dynamic range, and high integration, it can be used in future particle detecting experiments based on silicon detectors.     

A prototype silicon detector system for space cosmic-ray charge measurement

A readout electronics system used for space cosmic-ray charge measurement for multi-channel silicon detectors is introduced in this paper, including performance measurements. A 64-channel charge sensitive ASIC (VA140) from the IDEAS company is used. With its features of low power consumption, low noise, large dynamic range, and high integration, it can be used in future particle detecting experiments based on silicon detectors.     

水基切伦科夫μ子探测器的研究

利用高速带电粒子在透明介质中产生切伦科夫辐射的特性,以蒸馏水作为辐射介质,搭建了一个小尺寸(π×22.52cm2×45 cm)的切伦科夫探测器,对能量在GeV量级的μ子进行了相应的测量,考虑其他能量损耗、光传输和收集效率、阴极量子效率后,实验结果与理论估计值有比较高的相符度,可以初步断定仪器具备探测GeV量级μ子的能力.     

Search for UHE cosmic sources with a large-area underground muon detector

Summary The newly discovered gamma-ray emission from Cyg-X 3 with energies up to 2·10¹⁶eV gives the first evidence that particle acceleration in galactic gamma-ray sources can reach energies of the order of 10⁴ TeV. We discuss the detectability of this type of sources by an underground muon tracking detector with area of the order of ∼1000 m² and the physical information which could be obtained in this way. Paper presented at the 2° Convegno Nazionale di Fisica Cosmica, held at L'Aquila, 29 May–2 June 1984.     

Radiator design for detecting high-energy neutrons with a nuclear track detector

Subsequent to the proposal of a two-layer structured radiator for more efficient detection of high-energy neutrons with a plastic nuclear track detector (PNTD), its availability has been investigated both experimentally and theoretically. An inner deuterized hydrocarbon (CD₂) layer adjacent to PNTD should play the role of both a radiator of deuterons recoiled there and a degrader for energetic protons recoiled in the outer layer of a CH₂ material. It was found that the energy dependence of the efficiency was changed sensitively by the thickness of the CD₂ layer. A best combination of CH₂ and CD₂ thickness was estimated under a condition of a constant total thickness. For example, the sensitivity could be flattened within 20% between about 5 and 70 MeV by using -CD₂ and -CH₂.     

Parameter optimization of a stationary deepwater amplitude cerenkov muon detector

A condition that should be met in the design of both amplitude and temporal detectors for the muon track azimuth to be uniquely recovered is analytically found. An optimal algorithm for muon track reconstruction with an amplitude Cerenkov detector is elaborated. The optimization involves not only the design of the detector but also statistical methods for estimating auxiliary muon track parameters. An original procedure for computing the confidence interval of the muon track parameters is suggested. This procedure is based on the algorithm used for solving the nonlinear programming problem.     

High-efficiency and high-accuracy digital image correlation for three-dimensional measurement

The computational efficiency and measurement accuracy of the digital image correlation (DIC) have become more and more important in recent years. For the three-dimensional DIC (3D-DIC), these issues are much more serious. First, there are two cameras employed which increases the computational amount several times. Second, because of the differences in view angles, the must-do stereo correspondence between the left and right images is equivalently a non-uniform deformation, and cannot be weakened by increasing the sampling frequency of digital cameras. This work mainly focuses on the efficiency and accuracy of 3D-DIC. The inverse compositional Gauss–Newton algorithm (IC-GN²) with the second-order shape function is firstly proposed. Because it contains the second-order displacement gradient terms, the measurement accuracy for the non-uniform deformation thus can be improved significantly, which is typically one order higher than the first-order shape function combined with the IC-GN algorithm (IC-GN¹), and 2 times faster than the second-order shape function combined with the forward additive Gauss–Newton algorithm (FA-GN²). Then, based on the features of the IC-GN¹ and IC-GN² algorithms, a high-efficiency and high-accuracy measurement strategy for 3D-DIC is proposed in the end.     

The multistep avalanche chamber: A new high-rate,high-accuracy gaseous detector

A new particle detector relying on an unusual avalanche mechanism mainly mediated by UV photons permits multistage amplification of ionization electrons. Single electrons are detectable. Particle fluxes, orders of magnitude more intense than in wire chambers, are acceptable. Applications can be foreseen for ?erenkov light imaging, radio-chromatography, slow neutron and X-ray detection.     

高能伽玛源下碲锌镉探测器的针孔成像

采用新型室温碲锌镉(CdZnTe)辐射探测器,通过厚针孔系统对137Cs高能662 keV伽玛射线辐射源进行成像探测,得到了能谱图和放射源图像。计算分析了高能射线穿透效应对空间分辨力的影响,并对不同偏压下得到的图像进行比较与讨论。实验表明,当放大倍率不大时（小于3）,高能射线对准直器材料的穿透效应增大是限制图像空间分辨力的主要因素,探测器像素尺寸的大小对图像空间分辨力的影响并不明显。随偏置电压升高,探测器得到的图像会得到改善,但过大的偏压（大于1 000 V）会使晶体内部的电场不均匀性增大,降低信噪比从而降低图像品质。     

A multilayer scintillation detector of high-energy particles for satellite experiments

We describe the detecting system of a high-energy charged particle telescope spectrometer for a space experiment to be performed on the outer surface of the Russian section of the International Space Station and other spacecraft, including small satellites. The spectrometer’s detecting system is a multilayer scintillation detector (MSD) of polystyrene plates scanned by photomultipliers. It allows high-intensity fluxes of electrons (up to ～10⁵ cm^?2 s^?1) several milliseconds long with energies of 3 to 30 MeV to be measured with an accuracy of ～1 μs, along with time profiles and the evolution of particle energy spectra. The MSD is characterized by an energy resolution no worse than 10%, an angular resolution of ～10 degrees, a geometric factor of ～40 cm² sr, and a trigger system time resolution of ～20 ns.     

New method for measurement of a T-violating muon polarization in K + decays

A new method is proposed for measuring a T-violating muon polarization in the decays K ⁺ → π⁰μ⁺ν and K ⁺ → μ⁺νγ. The method is based on a complete reconstruction of kinematics in these decays by using a high-resolution π⁰ detector, an active muon polarimeter, and a nearly 4π efficient photon veto system. A high acceptance of the detector allows one to reach a statistical sensitivity to the T-violating muon polarization of less than 10^?4 in an experiment with stopped K ⁺ mesons.     

An electromagnetic calorimeter for the silicon detector concept

A silicon-tungsten calorimeter for silicon detector (SiD) at the International Linear Collider is under development. Recent progress is summarized.      

高能伽玛相机探测量子效率的蒙特卡罗模拟

探测量子效率（DQE）可被用来精确描述图像噪声通过成像系统的传播特性。根据级联理论,简洁得出了零频噪声传播情况下成像系统的DQE 表达式。采用蒙特卡罗程序MCNP 计算了高能X射线的硬化能谱在六种常用闪烁晶体中的能量沉积分布以及高能伽玛相机的DQE,分析了闪烁晶体的材料和厚度对DQE的影响。模拟结果表明,高密度、高原子序数是影响DQE的主要因素,在同样厚度下,LuAP和LSO转换屏的探测量子效率最高。