激光诱导原子电离实验中的多定标数据获取系统

简要介绍了一套应用于激光诱导原子电离实验中的多定标数据获取系统,获取系统分为前端CAMAC自动获取与通过网络连接的后台数据存储两部分,其特点是用户更改数据读出表文件而可以任意添加CAMAC前端中的定标器个数,也可以增加用于能量测量的ADC等实现多参数在线获取,获得的数据按照列表型ASCⅡ格式存放在微机硬盘中.     

一套用于激光多步共振电离截面测量的多定标数据获取系统

本文主要介绍了一套应用于激光多步共振电离截面测量的CAMAC多定标数据获取系统.它可以实现严格同步采集多个实验参数,并能灵活适应实验条件的宽范围变化.CAMAC前端的定标器数目可通过更改数据读出表文件来任意增减;获取方式分为自动重复获取和手动单次获取;获取时间单位可在1ms-800s范围内调节.经过测试得到,本数据获取系统的获取时间单位选择100s时长时间工作的稳定性(△t/t)好于±0.01%,充分证实了该套数据获取系统长时间在线采集实验数据的可靠性.最后利用这套系统同步测量了三台热电偶激光功率探头的功率-响应时间曲线.     

V-F变换在激光物理实验中的新型应用

介绍了一套十分适合应用于准连续激光物理实验的变换装置.该套装置不但可以将热电偶激光功率计输出的直流型模拟电压量变换成计数脉冲输出,还可以对光离子引起的、探测器给出的脉冲型模拟电压量进行累计变换.经过详细的模拟测试得知它变换激光功率的积分线性≤±0.015%,变换光离子脉冲信号的积分线性≤±0.23%.以上测试结果表明该套变换装置已经满足了一般激光物理实验的精度要求.     

用于不稳定核性质研究的激光共振电离技术

不稳定原子核的基本性质反映了核的内在结构和有效相互作用,可用于研究不稳定核的奇特结构。激光核谱技术通过测量核外电子光谱的超精细结构和同位素移位,可以核模型无关地提取原子核的多个基本性质,是研究不稳定核性质和结构的有力工具之一。多步激光共振电离方法是测量原子或离子超精细结构和同位素移位的方法之一。基于此,国际上发展了多种共振电离谱实验技术,用于放射性核束装置上开展不稳定核基本性质和结构研究。本文首先介绍了激光共振电离方法,以及由此发展的各种共振电离激光谱实验技术。随后详细讨论了近十年来刚发展起来的共线共振电离谱技术。此技术可同时实现超精细结构谱的高分辨和高灵敏度测量,正在核素版图大质量范围内的不稳定核性质和结构研究中发挥重要作用。最后分析了用于国内放射性核束装置的共振电离激光谱技术的发展现状及应用前景。     

激光共振电离质谱用钚源的制备及探测效率测定

为提高激光共振电离质谱（LRIMS）中钚的原子化效率,设计制备了金属包覆钚源,以期提高LRIMS测量痕量钚的灵敏度。本工作设计加工了适用于痕量钚制源的电沉积装置,研究了水相中痕量钚的电沉积条件,实现了痕量钚的定量电沉积;对比研究了金属铂和钛的电镀条件及性能,确定了以钛为包覆层的真空蒸镀条件,实现了镀层厚度为1 μm、金属钛包覆的高效钚源中钚的总沉积率达95%。研究表明,制备的高效钚源经过LRIMS测试,仪器对钚样品的总探测效率为2.5×10^-4,原子化效率提高至7.7%,较直接滴加源提高3个数量级,为LRIMS法高灵敏测量环境中痕量钚奠定了基础。     

激光功率计的变换与显示电路

介绍了激光功率计的变换与显示电路,该电路的主要功能是直接指示激光功率的大小,该电路把由激光功率计输出的模拟电压量变为数字脉冲输出,并且把输出脉冲的频率实时显示出来。本电路具有精度高、线性好、工作稳定的特点。     

激光有一定带宽时的光电离

研究了激光有一定带宽情况下的光电离。首先推导了三步光电离的公式，然后从含有激光带宽的方程组出发，计算了不同情况下的电离几率对于激光带宽的依赖关系，以计算结果分析了激光带宽的选取原则。     

应用面向对象方法设计的多路多道能谱获取系统程序

本文介绍了面向对象编程（ＯＯＰ）的特点及其用ＤＤ８０００型多路多道能谱获取系统仿真软件的设计思想和方法，本文还讨论了Ｗｉｎｄｏｗｓ环境下显示多路能谱的一些问题。     

基于微机的多参数核物理实验数据获取分析系统

介绍一台由微机控制的用CAMAC插件组成的多参数数据获取和离线数据分析系统。该系统采用软件控制的方法进行信号种类的甄别以及划定信号收集的范围。与用NIM系统构成的数据获取系统相比,在达到同样测量精度的基础上,降低了对硬件设备的要求。该系统再配合微型电离室、芪晶体探测器,被用来做裂变中子飞行时间谱的测量,给出了测量结果。     

一种用多并口获取数据的方法

提出一种利用多个通用并行接口组成的接口电路,实现计算机多道脉冲分析系统数据获取的方法,介绍了它的电路设计、工作原理及性能分析。     

Time profiles of ions produced in a hot-cavity resonant ionization laser ion source

The time profiles of Cu, Sn, and Ni ions extracted from a hot-cavity resonant ionization laser ion source are investigated. The ions are produced in the ion source by three-photon resonant ionization with pulsed Ti:Sapphire lasers. Measurements show that the time spread of these ions generated within laser pulses of about 30 ns duration could be larger than 100 μs when the ions are extracted from the ion source. A one-dimensional ion-transport model using the Monte Carlo method is developed to simulate the time dependence of the ion pulses. The prediction of the model agrees reasonably well with the experimental data. To reproduce the observed ion time profiles, we find it necessary to postulate that ion-wall collisions are suppressed inside the ion source by an undetermined ion confinement mechanism and that a substantial fraction of the extracted ions are generated in the vapor-transfer tube rather than the hot cavity. Three-dimensional modeling will be necessary to understand the strong reduction in losses expected from ion-wall collisions which we interpret as evidence for confinement.     

An experimental setup for surface ionization and desorption studies

The construction and function of an apparatus intended for negative surface ionization and other desorption studies are described. A molecular beam of the material to be ionized is formed. The number of particles that reaches the ionizer can be measured with a device which is sensitive to the momentum of the particles in the neutral beam. The extraction field is reversible, making it possible to study nonsteady ionization processes and to use the modulated voltage technique, providing a second method to determine the ionization efficiency. The reflection of the neutral beam at the ionizer can be estimated by comparing the two methods. The temperature of the ionizer is measured and controlled by a microcomputer, allowing studies like temperature programmed desorption. Mass analysis and a SEM detector provide a possibility to measure very low ion currents.     

An experimental evaluation of spatial distribution for deeply penetrating protons in carbon material

The peak profile of the 4.8-MeV resonance by the ¹²C(p,p)¹²C reaction in backscattering geometry has been analyzed to examine two kinds of stragglings of proton, i.e. the depth straggling in the incoming path and the energy loss straggling in the outgoing path. The analysis, which is combined with existing theoretical treatments for the stopping process and the energy loss straggling, has made it possible to deduce the penetration depth and its spread at the resonance position in carbon materials. The present method, as a new tool for direct inspection of ion beams inside target material, is explained in detail.     

An experimental procedure for measuring accelerations and strains from a tie down system of a heavy nuclear transport package during a rail journey

Abstract

The transportation of nuclear waste and new nuclear fuel is an important aspect in sustaining the generation of electricity by nuclear power. The design of packages that satisfy regulatory requirements for normal operating and accident conditions is a complex engineering challenge. The ancillary equipment used to constrain the packages to their conveyance, a tie down system, is part of a multicomponent system used to transport packages. Traditionally, the individual components of the transport system have been designed in isolation. This approach does not account for the interaction between components of the system such as the conveyance, tie down system and package. The current design process for tie down systems is well established but, due to its heuristic development, suffers from uncertainties over which loading conditions should be applied. This paper presents a method for collecting measured acceleration and strain data that can be used to derive customised load cases for the design of tie down systems during rail transportation. The data was collected from a tie down system that restrained an empty TN81 package, weighing 99·7 tonnes during a routine rail journey from Barrow-in-Furness to Sellafield. Furthermore, the data can be used to validate modern computer models, allowing for the development of the previously described holistic approach to tie down system design. The results are unique because an ensemble of acceleration and strain time histories from a transport system laden with a nuclear package is unprecedented. A visual examination indicates that the loading a tie down system incurs during a rail journey consists of low magnitude accelerations. The measurement points also show that the general trend of acceleration levels is highest nearest the track and is attenuated by the package. The implications for the design of tie down systems are that two potential failure modes, fatigue and static strength, have been identified. The data provides scope for customising accurate static strength and fatigue calculations using modern computational techniques. This allows for the safety margins inherent in new designs to be determined and optimised design solutions made possible.

INS makes no representations or warranties or any kind concerning this article, express or implied, statutory or otherwise, including without limitation, warranties of accuracy or the absence of errors.     

二维阵列电离室探测器数据采集系统设计

介绍了用于对肿瘤放射治疗进行剂量验证的二维阵列电离室探测器的数据采集系统的设计与开发。文章描述了该二维阵列电离室探测器系统的构成以及工作原理,重点讨论了该探测器的数据采集子系统的设计过程,并完成了由前置放大器、前放控制器、数据采集控制器构成的数据采集子系统的开发。用户端可通过TCP/IP方式对探测器系统的参数进行设置,并进行数据高速采集、获取和进一步的处理。     

用于快中子引起带电粒子核反应研究的屏栅电离室及双参数测量系统

本文主要介绍和描写了用于快中子引起的发射带电粒子核反应研究的具有共阴极的两个背靠背的双重屏栅电离室。用双参数数据获取系统可同时得到阳极和阴极的关联信号。由此可以研究由贴在阴极上的靶物质发射的带电粒子的能量和角分布，实验上用Ｐｕα放射源来检验屏栅电离室的基本性能，由双参数数据获取系统得到其双维谱，经数据处理之后，其角分布基本上呈现各向同性分布，对Ｐｕα放射源的能量（Ｅ＝５．４９９ＭｅＶ），其能量分辨串为～２％，此电离室已用于（４０）￣Ｃａ（ｎ，α）和￣（６４）Ｚｎ（ｎ，α）等核反应研究工作。