Detailed characterization of polycapillary focusing x-ray lenses by a charge-coupled device detector and a pinhole

A method to measure the detailed performance of polycapillary x-ray optics by a pinhole and charge coupled device(CCD)detector was proposed in this study.The pinhole was located between the x-ray source and the polycapillary x-ray optics to determine the illuminating region of the incident x-ray beam on the input side of the optics.The CCD detector placed downstream of the polycapillary x-ray optics ensured that the incident x-ray beam controlled by the pinhole irradiated a specific region of the input surface of the optics.The intensity of the output beam of the polycapillary x-ray optics was obtained from the far-field image of the output beam of the optics captured by CCD detector.As an application example,the focal spot size,gain in power density,transmission efficiency,and beam divergence of different parts of a polycapillary focusing x-ray lenses(PFXRL)were measured by a pinhole and CCD detector.Three pinholes with diameters of 500,1000,and 2000μm were used to adjust the diameter of the incident x-ray beam illuminating the PFXRL from 500μm to the entire surface of the input side of the PFXRL.The focal spot size of the PFXRL,gain in power density,transmission efficiency,and beam divergence ranged from 27.1μm to 34.6μm,400 to 3460,26.70%to 5.38%,and 16.8 mrad to 84.86 mrad,respectively.

Analysis of displacement damage effects on the charge-coupled device induced by neutrons at Back-n in the China Spallation Neutron Source

Displacement damage effects on the charge-coupled device(CCD)induced by neutrons at the back-streaming white neutron source(Back-n)in the China Spallation Neutron Source(CSNS)are analyzed according to an online irradiation experiment.The hot pixels,random telegraph signal(RTS),mean dark signal,dark current and dark signal non-uniformity(DSNU)induced by Back-n are presented.The dark current is calculated according to the mean dark signal at various integration times.The single-particle displacement damage and transient response are also observed based on the online measurement data.The trends of hot pixels,mean dark signal,DSNU and RTS degradation are related to the integration time and irradiation fluence.The mean dark signal,dark current and DSNU2 are nearly linear with neutron irradiation fluence when nearly all the pixels do not reach saturation.In addition,the mechanisms of the displacement damage effects on the CCD are demonstrated by combining the experimental results and technology computer-aided design(TCAD)simulation.Radiation-induced traps in the space charge region of the CCD will act as generation/recombination centers of electron-hole pairs,leading to an increase in the dark signal.

Investigating the Thermal Stress of Millisecond Pulsed Laser Irradiation on Charge-Coupled Devices

In this study, a two-dimensional model describing thermal stress on a charge-coupled device (CCD) induced by ms laser pulses was examined. Considering the nonlinearity of the CCD’s material parameters and the melting phase transition process of aluminum electrode materials was considered by using equivalent specific heat capacity method, the physical process where a laser pulse irradiating a CCD pixel array was simulated using COMSOL Multiphysics software. The temperature field and thermal stress field were calculated and analyzed. In order to clarify the mechanism producing damage on the CCD detector, Raman spectra from silicon were measured with a micro-Raman spectrometer to determine stress change in the CCD chip. The procedure presented herein illustrates a method for evaluating strain in a CCD after laser irradiation.

Metal-Halide Perovskite Submicrometer-Thick Films for Ultra-Stable Self-Powered Direct X-Ray Detectors

Metal-halide perovskites are revolutionizing the world of X-ray detectors,due to the development of sensitive,fast,and cost-effective devices.Self-powered operation,ensuring portability and low power consumption,has also been recently demonstrated in both bulk materials and thin films.However,the signal stability and repeatability under continuous X-ray exposure has only been tested up to a few hours,often reporting degradation of the detection performance.Here it is shown that self-powered direct X-ray detectors,fabricated starting from a FAPbBr_(3)submicrometer-thick film deposition onto a mesoporous TiO_(2)scaffold,can withstand a 26-day uninterrupted X-ray exposure with negligible signal loss,demonstrating ultra-high operational stability and excellent repeatability.No structural modification is observed after irradiation with a total ionizing dose of almost 200 Gy,revealing an unexpectedly high radiation hardness for a metal-halide perovskite thin film.In addition,trap-assisted photoconductive gain enabled the device to achieve a record bulk sensitivity of 7.28 C Gy^(−1)cm^(−3)at 0 V,an unprecedented value in the field of thin-film-based photoconductors and photodiodes for“hard”X-rays.Finally,prototypal validation under the X-ray beam produced by a medical linear accelerator for cancer treatment is also introduced.

Progress of Terahertz Devices Based on Graphene

Graphene is a one-atom-thick planar sheet of sp2-hybridized orbital bonded honeycomb carbon crystal. Its gapless and linear energy spectra of electrons and holes lead to the unique carrier transport and optical properties, such as giant carrier mobility and broadband flat optical response. As a novel material, graphene has been regarded to be extremely suitable and competent for the development of terahertz （THz） optical devices. In this paper, the fundamental electronic and optic properties of graphene are described. Based on the energy band structure and light transmittance properties of graphene, many novel graphene based THz devices have been proposed, including modulator, generator, detector, and imaging device. This progress has been reviewed. Future research directions of the graphene devices for THz applications are also proposed.

Progress in Antimonide Based III-V Compound Semiconductors and Devices

In recent years, the narrow bandgap antimonide based compound semiconductors (ABCS) are widely regarded as the first candidate materials for fabrication of the third generation infrared photon detectors and integrated circuits with ultra-high speed and ultra-low power consumption. Due to their unique bandgap structure and physical properties, it makes a vast space to develop various novel devices, and becomes a hot research area in many developed countries such as USA, Japan, Germany and Israel etc. Research progress in the preparation and application of ABCS materials, existing problems and some latest results are briefly introduced.

高速数字化三维集成式CCD-CMOS图像传感器

为了解决CCD与CMOS工艺兼容性低、互连集成制作难度大,以及芯片间接口匹配和高性能兼备等问题,对CCD器件拓扑结构与像元、CMOS读出电路、三维异质互连集成及高密度引脚封装等技术进行研究,提出了一种1024×256阵列规模的集成式CCD-CMOS图像传感器。该器件实现了CCD信号的高精度数字化处理、高速输出及多芯粒的技术融合,填补了国内CCDCMOS三维集成技术空白。测试结果表明:集成CCD-CMOS器件的光响应和成像功能正常,双边成像效果良好,图像无黑条和坏列,互连连通率(99.9%)满足三维集成要求,实现了集成式探测器件的大满阱高灵敏度成像(满阱电子数达165.28ke^(-)、峰值量子效率达86.1%)、高精度数字化(12bit)和高速输出(行频率达100.85kHz),满足集成化、数字化、小型化的多光谱探测成像系统要求。

基于机器视觉的呼出气体酒精含量检测仪自动检定装置

当前呼出气体酒精含量检测仪检定工作耗时耗力,检定过程需要人工进行判读和记录,针对该问题研制一套呼出气体酒精含量检测仪自动检定装置。依据检定规程的要求,设计配气装置实现对气体的气路设计及温度和流量等的控制。基于机器视觉系统使用Halcon联合C#开发识别算法,利用Canny边缘算法提取感兴趣区域,定位提取示值字符后训练多层感知器来识别示值结果,并实现检定过程的自动选择和报告的自动生成。实验结果表明:对五种型号的呼出气体酒精含量检测仪示值的识别准确率达到了99.5%以上,平均识别时间小于200 ms,对后续检定的平均全过程时间从3.5天缩短至1.5天。该装置满足检定规程的要求,可以应用于各地计量机构的检定工作中,具有实用价值。

直接型卤素钙钛矿X射线探测器结构设计研究进展

X射线探测技术在医疗诊断、安防检测和科学研究等领域有着广泛的应用,直接型X射线探测器拥有更高的理论探测效率、空间和能量分辨率,受到了国内外的广泛关注。钙钛矿材料因其X射线衰减系数大、体电阻率高、光学带隙合适以及易大面积制造等优势,成为直接型X射线探测器的理想材料。随着对探测性能的需求的不断提高,合理的器件结构设计显得尤为重要。本文从电极工程和能带工程两个方面出发,综述了有关直接型钙钛矿X射线探测器器件结构设计的最新进展。最后,我们对这些研究进展进行了总结,并对未来的发展进行了展望。我们希望这篇综述能为研究者们提供参考和启发。

基于溶液法制备卤化铅钙钛矿的直接型辐射探测器研究进展

X射线和γ射线探测在医学成像、安防检查、国土安全、无损检测等各个领域得到广泛应用,钙钛矿材料具有高辐射吸收系数、高载流子迁移率-寿命乘积、特殊的缺陷容忍特性而成为辐射探测器件优异的候选材料。溶液法在制备钙钛矿材料方面具有显著的优势,溶液法的成本较低,能在低温或环境条件下制备,更易推行工业化生产,是未来优化材料体系,制备高质量、大尺寸晶体材料的关键技术。本文从溶液法制备卤化铅钙钛矿材料的角度出发,分析晶体生长及材料组成对辐射探测性能的影响,重点介绍从优化晶体生长质量和器件结构设计等方面提升辐射探测性能,最后总结钙钛矿材料在辐射探测领域面临的挑战,并展望了未来研究的发展方向,期望为钙钛矿材料在辐射探测领域走向工业化提供参考。

呼吸机检测仪校准装置的研发

近年来,呼吸机检测仪已逐渐随呼吸机的使用量不断增加而增加,由于我国目前对其校准的方式比较复杂,因此,为提供有效的量值溯源,需有效地研制出一台多参数集成的呼吸机检测仪校准装置。本文研制了一套呼吸机检测仪校准装置,保证了量值准确可靠,可实现医院对其质量的有效监测与质量控制,从而保证治疗效果。

中国医疗器械产品出口的空间格局及影响因素——基于“省份-国家(地区)”二模网络视角

基于“省份-国家(地区)”二模网络视角,选用2003—2022年数据和社会网络分析、地理探测器等方法,研究了中国医疗器械产品出口的空间格局演变特征及其影响因素。结果表明,中国医疗器械产品出口贸易总量在持续增长,距离衰减效应不明显,其出口网络在网络通达性、联系程度和规模方面均提升显著,中国东部沿海省份和境外的美国、日本、德国等在网络中处于核心位置;在蓄意攻击模式下,将美国从网络中剔除后,中国医疗器械产品出口网络健壮性仍较强;东部地区大部分省份出口韧性较强,北京和上海一直分别处于极强和次强比较优势;生产要素、政策环境、技术创新水平和需求条件对中国各省份医疗器械产品出口影响显著,且其相关性在逐渐增加。

过氧化氢气体检测仪校准装置量值溯源的一点思考

探讨了一种过氧化氢气体检测仪校准装置(以下简称校准装置)量值溯源的方法。过氧化氢气体被浓硫酸吸收后与高锰酸钾容量标准物质产生化学反应,过氧化氢量值与高锰酸钾量值一一对应。由于高锰酸钾容量标准物质为国家二级标准物质,其量值可溯源至国家计量基准,于是过氧化氢气体量值也具有可溯源性,通过校准装置测量该过氧化氢气体进行校准,其量值与过氧化氢气体量值的差值,得到该校准装置的仪器示值误差,从而建立了校准装置量值溯源的途径。

家用可燃气体探测器现场测试方法

把家用可燃气体探测器作为研究对象,按照产品的工作方式及采样特点,以提供安全防护保障为目的,结合国标要求,提出了针对安装现场的检测方法及配套装置。方法科学合理、有效,装置设计独特,操作方便。

过氧化氢气体检测仪校准技术初探

过氧化氢气体具有优异的灭菌效果,被广泛应用于各行各业,但其检测仪缺乏有效校准技术和方法。由于该气体稳定性较差,因此,本文根据各种应用条件下的浓度限值规定、传感器类型和量程,分析了校准技术的不足,研制了过氧化氢气体高效动态校准装置,并进行实验验证。结果表明:标准装置的示值误差较小,可为该检测仪的校准技术提供参考。

TEM study on Si_(0.65) Ge_(0.35) /p Si HIP infrared detector

Microstructure of P + Si 0.65 Ge 0.35 /p Si HIP infrared detector has been studied by using localization cross section transmission electron microscopy. The photosensitive region of the detector consists of 6 P + Si 0.65 Ge 0.35 layers and 5 UD Si layers, which are flat and have thickness of 6 nm and 32 nm, respectively. A stress field exists on the interface between Si 0.65 Ge 0.35 and UD Si layers, but no any crystal defect has been found in this region, except the edges of this region. Both Si 0.65 Ge 0.35 and UD Si layers on amorphous SiO 2 layer consist of polycrystals and are in wave. There is defect area in the edges of photosensitive region. The area appears in a shape of inverse triangle and the maximum width is less than 120 nm. The crystal defects are stacking faults and microtwins.

Origin of peculiar inerratic diffraction patterns recorded by charge-coupled device cameras

A peculiar and regular diffraction pattern is recorded while using either a color or a monochrome charge-coupled device (CCD) camera to capture the image of the micro air plasma produced by femtosecond laser pulses. The diffraction pattern strongly disturbs the observation of the air plasma, so the origin and eliminating method of these diffraction patterns must be investigated. It is found that the Fourier transform of the periodic surface structure of either the mask mosaic of the color CCD or the pixel array of the monochrome CCD is responsible for the formation of the observed pattern. The residual surface reflection from the protection window of a CCD camera plays the essential role in forming the interesting two- dimensional diffraction spots on the same CCD sensor. Both experimental data and theoretical analyses confirm our understanding of this phenomenon. Therefore remov-ing the protection window of the CCD camera can eliminate these diffraction patterns.

标记单光子源下探测器死时间的量子密钥分配

考虑到当光子传输速率过高时,量子密钥分配协议在实际应用中会受到探测器死时间的影响,因此对基于标记单光子源协议的安全密钥生成速率和探测器死时间之间的关系进行了探究。首先,在考虑和不考虑探测器死时间这两种情况下,探究了安全密钥生成速率和探测器死时间之间的关系。结果表明:当光子传输速率过高时,探测器死时间的存在的确会影响安全密钥生成速率。进一步分析了不同探测器死时间下安全密钥速率的生成情况。结果表明:探测器死时间的取值越大,得到的安全密钥生成速率就越低,安全密钥生成速率的极限值和探测器死时间τ之间的关系为4.2/τ。

Intelligent Bio-Detector

The objective of this document is to describe the design and implementation of an intelligent biomedical system. The system consists of an array of multiple sensors. The sensors are connected to the Arduino Uno device to allow data capture and processing. The captured signals from the sensors are then digitized by the microcontroller. The data from the microcontroller are accessible via two different portals: the LCD display and the LabVIEW graphical user interface. The microcontroller is also equipped with a GSM module to send the alert message to the user upon occurrence of events that simulate abnormal activity in the biological parameters of the user.

液晶太赫兹光子学研究进展

液晶作为液态和固态之间的中间态,具有液体的流动性和晶体的各向异性,其指向矢灵活可调,从微波到紫外都有广泛应用。近年来液晶光子学在太赫兹波段展现出巨大应用前景,本文综述了基于液晶的太赫兹源、可调太赫兹器件和太赫兹探测器的研究进展,探讨了未来液晶太赫兹光子学的发展趋势,如新型铁电向列相、液晶拓扑在太赫兹领域的应用,多模式、多参量的太赫兹波按需产生、调制与探测等。