软X射线皮秒变象管扫描相机

在激光核聚变的研究中,在加热压缩靶球发生内爆时所产生的高温高密度等离子体的光谱辐射主要为软X射线,对这些软X射线的研究可以获得有关等离子体的电子温度、电子能量分布、各种不稳定的形态及这些参量随时间变化的信息。然而,产生X射线的过程是皮秒量级,受激光脉冲照射的靶球直径仅100微米,所以,需要有皮秒量级时间分辨及微米量级空间分辨的X射线诊断手段。软X射线皮秒变象管扫描相机就是应此需求而研制的。它是X射线波段时间分辨率最高的探测分析仪器,且具有高的空间分辨能力。把这种相机与X射线谱仪结合,构成照相记录的瞬时X射线谱仪;与X射线针孔成象系统相配合可测定空间分辨一维图象随时间变化的情况。     

错位双光栅色散元件设计及衍射效率研究

设计了一种错位双光栅色散元件,与条纹相机耦合实现了0.1~5keV范围X射线时间分辨谱的测量.该色散元件由2 000lp/mm和5 000lp/mm两块子光栅在空间错位排布而成,低密度光栅测量低能段软X射线(100~1 000eV),高密度光栅测量中能段软X射线(1 000~5 000eV),通过空间错位实现能谱拼接.在同步辐射源上使用单色能点对其进行标定,获得了错位双光栅衍射效率的实验结果.根据光栅的结构特性,结合标定结果与严格耦合波分析理论,计算得到了100~5 000eV能区光栅的绝对衍射效率曲线,并给出了错位双光栅的解谱方法.该错位双光栅能够有效提升透射光栅谱仪的性能,为高温等离子体诊断提供宽谱X射线时间分辨谱定量测量.     

X射线辐射输运分解实验研究

在“星光Ⅱ”激光装置上进行了X射线辐射输运分解实验研究.实验中利用高时空分辨的MCP选通X射线皮秒分幅相机和软X射线条纹相机从缝口观测腔内壁X射线辐射时空分布,得到X射线在腔中的输运速率、X射线持续发射时间和轴向强度衰减量;利用X射线CCD针孔透射光栅谱仪观测到腔内X射线辐射光谱随空间位置的变化,得到X射线在输运过程中被多次吸收和发射后谱的变化特征;用X射线二极管和亚千X射线能谱仪分别得到源和输运末端X射线辐射总量和辐射温度.介绍了实验中采用的诊断技术和实验方法,并给出了获得的典型结果. 关键词：     

Silex-I飞秒激光装置X射线探测系统时间特性北大核心CSCD

在Silex-Ⅰ飞秒激光装置上,利用32fs、800nm的激光辐照平面金靶,产生小于1ps的X射线脉冲,作为δ脉冲X射线源,研究XRD探测器的时间响应特性,并且探索X射线条纹相机时间分辨和分幅相机曝光时间的X射线标定方法。实验给出了XRD探测器的时间响应特性。解决了条纹相机和分幅相机触发晃动问题,给出了条纹相机时间分辨和分幅相机曝光时间的X射线标定方法,初步给出条纹相机时间分辨和分幅相机曝光时间。     

基于移位双光栅色散元件的X射线谱仪研制

本文针对激光等离子体X射线诊断的需求,设计开发了移位双光栅X射线谱仪.该谱仪采用高线对密度和低线对密度的两种光栅组成移位双光栅作为核心衍射组件,高密度光栅能够提高中、高能区(1000—5000 eV)的能谱分辨率,低密度光栅足够满足低能区(100—1000 eV)测量的能谱分辨率要求,控制了低能区谱线的分布空间,保证足够的测量范围.两种光栅相互配合实现了谱仪整体性能提升.本文提出了移位双光栅X射线谱仪结构设计方法和参数指标,完成了移位双光栅X射线谱仪的集成调试和实验应用,获得了时间分辨的X光谱实验数据,测谱范围0.1—5.0 keV,谱分辨0.04 nm,时间分辨好于30 ps.移位双光栅X射线谱仪可以最大程度地利用记录面的长度,实现高时间分辨和宽谱X射线测量.     

消像散掠入射平场光栅谱仪及其在等离子体XUV光谱诊断中的应用

研制成一台由柱面反射镜和球面反射镜组成的掠入射前置光学系统和变间距球面光栅组成的掠入射平场光栅谱仪,它不仅有较高的效率和光谱分辨,调整方便,而且还具有在4.4nm～30nm波长范围里同时获得一维空间分辨光谱的能力.用该谱仪成功地获得了线聚焦激光产生的Si,Cu及其它元素的等离子体柱的轴向空间分辨光谱.该谱仪很适合与具有平直接收表面的光电探测器,如软X射线条纹相机等联用以获得时间分辨光谱.     

X光分幅相机-平面镜配接方法研究

利用X光谱仪用平面镜备件以及实验室常用五维调节架,设计了X光平面镜与X光分幅相机配接的探索方案,并对系统调节中各元件调节误差带来的影响进行了一定的分析,详细描述了系统的瞄准调节方法和过程.利用激光打靶实验,对X光平面镜与X光分幅相机的配接方法进行了检验.实验过程和结果表明,该方法系统结构和实施都较为简单,可以比较容易地在分幅相机微带上获得经平面镜反射的靶目标针孔像,实现～50 ps的时间分辨、10～20 μm的空间分辨及几十倍的能量分辨.     

用于测量Z箍缩铝等离子体K层辐射的邻苯二甲酸氢铊弯晶摄谱仪

 基于邻苯二甲酸氢铊(TAP)弯晶和软X射线分幅相机建立了一套4通道的时空分辨弯晶摄谱仪,测谱范围1 500～2 300 eV,时间分辨约2 ns。分析了谱仪各环节的信号传递和转换过程对系统谱响应的影响。利用该谱仪在“强光一号”加速器(约1.5 MA, 80～100 ns)Al丝阵Z箍缩实验中获得了时间分辨及时间积分的Al等离子体K层辐射谱,记录到了类H、类He离子主要共振线及类Li、类He离子双电子复合伴线。将摄谱结果与分能区X射线图像进行了比较。时间分辨的发射谱相对强度与积分结果有明显不同,反映了等离子体在5～10 ns时间尺度上的电子温度和离子布居变化。     

线状锗等离子体X射线线谱的时间分辨测量

用自行研制的X射线条纹晶体谱仪首次测量了线状锗等离子体的X射线时间分辨谱。给出了类Ne-锗L线共振线的时间演化过程,并用类Ne-锗L线共振线与其双电子俘获伴线的相对强度比粗估了锗等离子体的电子温度及其随时间的变化,实验给出了X光激光增益区介质的电子温度为400～760eV,同时给出了电子温度保持相对恒定的时间不小于90ps(电子温度变化小于2％)。     

一种用于Z箍缩实验的软X射线成像系统

基于塑料闪烁体转换和光学条纹相机的方法建立了一套用于Z箍缩实验中的软X射线条纹图像诊断系统,解决了以往实验中使用的X射线条纹相机易被电磁环境干扰以及相机电极部件易被实验产生的高速粒子损伤的问题.诊断系统的光谱响应范围主要集中在0.2-10 keV,系统的空间分辨率经过理论评估小于120μm,通过标定闪烁体对X射线的时间响应特性给出了系统的时间分辨率约为1 ns.诊断系统拍摄到了铝丝阵内爆等离子体的一维空间和时间分辨的X射线条纹图像,给出了等离子体的内爆一致性和辐射均匀性等特征信息.     

一种基于热释电效应的X射线荧光分析谱仪

利用热释电晶体实现了一个X射线激发源,并以此激发源和高能量分辨率的硅漂移探测器构建了一个X射线荧光分析谱仪。首先通过分析计算热释电晶体厚度和靶厚度对产生X射线的影响选定了激发源的设计参数;然后测量了激发源发射的X射线本底,其能量范围在1～27 keV,包含有Cu和Ta的特征X射线,最大强度在每秒3 000个计数以上,对本底的测量同时显示出谱仪的探测器部分对Cu的8.05 keV特征峰的分辨率达到210 eV,具有很高的能量分辨率;最后使用该谱仪测试了Fe,Ti和Cr等三种单质样品和高钛玄武岩样品,测试结果表明该谱仪可以有效的分析出样品的元素成分。由于这种X射线荧光分析谱仪的各组成部分体积都很小,进一步便携化后非常适合于非破坏、现场和快速的元素分析场合。     

高反射效率高定向性的热解石墨晶体X射线谱仪

基于高定向热解石墨晶体(highly oriented pyrolitic graphite,HOPG)研制了一种新型反射式X射线谱仪.该谱仪具有高反射效率、较高能谱分辨率及相对较宽的能谱测量范围.根据计算,在相同的入射条件下,该谱仪的效率比一般X射线弯晶谱仪高3个量级;谱仪能谱分辨率理论值最高达350;理论探测范围是6.891keV至9.193 keV.我们将该谱仪应用在高功率密度激光与固体靶相互作用的实验中,发现在普通弯晶谱仪无法采到信号的实验条件下,HOPG谱仪依然采集到清晰的Cu K谱线.分析发现在8.048 keV(Cu的Kα光子能量)附近的能谱分辨能力最高达到40 eV,分辨率大于200.     

Design and performance evaluation of SDD based X-ray spectrometer for future planetary exploration

Silicon Drift Detector (SDD) based X-ray spectrometer has been developed for obtaining the elemental composition of unknown samples by detecting fluorescent X-rays in the energy region 1–25 keV by a non-destructive process. The use of new technology X-ray detector provides good energy resolution for detecting the elements separated with ～150 eV apart. Here we present the design of a complete X-ray spectrometer intended for use in the future space-born experiment. The low energy threshold of <1 keV and the energy resolution of ～150 eV at 5.9 keV, as measured from the system is comparable to the standard spectrometers available off-the-shelf. We evaluated the system performance for different signal peaking time, as well as for different input count rates and show that the performance remains stable for incident count rate up to 20,000 counts per second. We have also carried out a ‘proof of concept’ experiment of measuring fluorescent X-ray spectrum from various standard XRF samples from the USGS catalog irradiated by the laboratory X-ray source ²⁴¹Am with 1 mCi activity. It is shown that intensities of various characteristic X-ray lines are well correlated with the respective elemental concentrations. A specific effort has been made while designing the developed X-ray spectrometer to use electronic components which are available in space grade so that the same electronic design can be used in the upcoming planetary missions with appropriate mechanical packaging.     

用于激光等离子体诊断的亚千X射线能谱仪

本文简介了由滤片-X射线二极管阵列组成的具有亚纳秒时间分辨的亚千X射线能谱仪。在0．1到1．5keV能区能量分辨约为200eV。着重介绍了谱仪的结构和应用，数据处理及误差。并就激光-金平面靶相互作用实验中，在激光强度约10^14w／cm^2条件下获得的部份数据进行了简化处理，给出了激光等离子体亚千X射线辐射能谱，由此推出等离子体辐射温度。     

An ultrahigh vacuum electron spectrometer for surface studies

A high-resolution electron spectrometer has been constructed for the study of clean metal surfaces and their interactions with gases. In its present form it is most suitable for the study of evaporated films but may also be used for ribbons, single crystals, or powders. Electron spectra induced by three sources, X-ray, vacuum ultraviolet, or electron impact, may be recorded sequentially. Electron energy analysis is normally performed by settin the analyzer (10 cm radius, hemispherical) to pass electrons of a fixed energy and applying a scanning retarding potential to the sample. The limiting instrument absolute resolution is about 25 meV FWHM at 5 eV analyzing energy, as judged by an He I gaseous argon spectrum. Resolution can be traded for sensitivity by analyzing at higher electron energies (up to 100 eV), or by means of an external slit-width adjustment mechanism. The spectrometer carri a preparation chamber which has a variety of demountable sample preparation, cleaning, and reaction monitoring devices. Spectra from gold, silver, and     

Experimental investigation of supersonic radiation propagation in low-density plastic and copper-doped foams

1 Introduction The investigation of supersonic radiation wave transporting in low density foam pro-duced by thermal radiation is of crucial importance in inertial confinement fusion (ICF) research[1]. When the intense radiation flux is incident in the media, first, a supersonic heat wave is formed which propagates into the undisturbed material. In time, due to the increasing mass of heated material, it slows down and is overtaken by a shock wave,thus becoming of the ablative type. Normally, …     

A three‐crystal spectrometer for high‐energy resolution fluorescence‐detected X‐ray absorption spectroscopy and X‐ray emission spectroscopy at SSRF

A Johann‐type spectrometer for the study of high‐energy resolution fluorescence‐detected X‐ray absorption spectroscopy, X‐ray emission spectroscopy and resonant inelastic X‐ray scattering has been developed at BL14W1 X‐ray absorption fine structure spectroscopy beamline of Shanghai Synchrotron Radiation Facility. The spectrometer consists of three crystal analyzers mounted on a vertical motion stage. The instrument is scanned vertically and covers the Bragg angle range of 71.5–88°. The energy resolution of the spectrometer ranges from sub‐eV to a few eV. The spectrometer has a solid angle of about 1.87 × 0^?3 of 4π sr, and the overall photons acquired by the detector could be 10⁵ counts per second for the standard sample. The performances of the spectrometer are illustrated by the three experiments that are difficult to perform with the conventional absorption or emission spectroscopy. Copyright © 2016 John Wiley & Sons, Ltd.     

Der Energieverlust von l MeV-Elektronen in sehr dünnen Schichten

Energy straggling of electrons passing through a thin layer of matter is no longer described by a Landau distribution if the thickness becomes smaller than a given value depending on the ionization energy of the electron shells. Systematic measurements of the energy loss of 1 MeV electrons in various materials have been done using a magnetic spectrometer device which gave an energy resolution of 460 eV (and 1800 eV in case of thicker foils). The results confirm theoretical calculations of corrections due to shell effects and apparatus resolution except for foils below 3 mg/cm².     

A Simple X-ray Spectrometer and PC-based Data Acquisition System for Newly Developed X-ray Source Based on Laser Compton Scattering

A simple X-ray spectrometer and a PC-Based Data Acquisition System(DAS) have been developed newly in Shanghai Institute of Applied Physics(SINAP),Chinese Academy of Sciences (CAS) for the measurement of the X-ray source generated using laser Compton scattering.The system consists of liquid nitrogen cooled high resolution Si(Li) detector,electronics and a DAQ.The Si(Li) detector was designed and made by Center of Advanced Instruments in SINAP,CAS,it allows us to measure X-rays with the energy up to 60 keV and the energy resolution(FWHM) of 184 eV at 5.9 keV.We measured the system uncertainty was 0.2 eV and time drifting of detector was 0.05% both at 5.9 keV.The DAQ was based on Object-Oriented software LabVIEW 7.1,it has data on-line analysis and original data saved functions.     

软X光Dante谱仪的平滑解谱算法及其在Z箍缩诊断中的应用

 针对自行研制的8通道Dante谱仪,提出了一种使用B样条曲线进行平滑解谱的算法,并用黑体谱对其进行了验证。计算结果表明：新算法与使用矩形函数解谱的算法相比,对能谱轮廓与总辐射强度的反演精度均有明显提高。给出了“阳”加速器氩气喷气Z箍缩实验的测量波形,由8通道Dante谱仪的测量结果解谱得到的软X光峰值辐射功率和总能量分别为40.5 GW和851 J,与软X光功率计经修正后的测量结果相一致。