A remote data collection system for CO gas has been designed in order to establish the multi detectors gas probe system.The design details include the integrated design,hardware function design and software function design.The user interface with simplicity,high effectiveness and based on the network has been set by Groov as the core.The data collection and remote transmission have been implemen ted by the hardware function design.The software function design includes the controller lower machine programming and Groov Box programming.Many performance tests have been developed for the collection system,including signal quotation errors,repetition,alarm initialization and function,response time,sta bility,zero excursion and range excursion.The testing results show that this system can satisfy the gas detection and data collection requirements under the specific conditions.

放射性气溶胶的捕集技术是气溶胶放化分析的前提,对其进行研究有利于促进气溶胶放化分析的发展.本工作通过使用不同滤材的组合,构建气溶胶过滤器,研究放化分析的气溶胶取样技术,实验结果表明:金属烧结毡与高效滤材进行组合后,其捕集效率达到98％以上,利用爆竹爆炸产生的气溶胶,进行模拟取样实验,在30 min内可获得100 mg以上的0.5 μm以上粒径的气溶胶,满足放化气溶胶取样的要求.

核取证学中材料成分分析、核恐怖事件中裂变产物分析和大样品活化分析等非破坏性测量中,探测效率刻度存在较大的挑战.本文解析了大样品多核素相对效率分析方法的基本原理,建立了基于多元素相对效率拟合方法.并通过某特殊形状铀辐照样品中裂变产物的特征峰信息,进行了双核素(母子体)和三核素(非母子体)效率拟合验证,研究表明多核素自刻度方法校准因子与母子体衰变校正因子在2％误差范围内一致.研究结果为特殊形状辐射样品无损分析技术奠定了基础.

放射性气体的物化特征对采集方式和测控技术的选择有极大影响.为研制用于环境监测的放射性气体收集装置,率先进行了具有温度、压力监测的环形结构测控系统的设计.设计内容包括测控系统的总体设计、流程与软件设计、远程测控子站设计与抗干扰设计.其中的总体设计为具有主控单元、环网通讯单元和远程测控单元的三层结构.设计结果表明,通信环网冗余、控制器冗余、输入输出模块冗余等技术的采纳将大大提高测控系统的稳定性、可靠性和适应性.

The application of TSI 3080 Electrostatic Classifier in sensitivity calibration for Dust Particle Counter is introduced.TSI 3080 Electrostatic Classifier can be used for extracting particles within a narrow range from the Particle Size Standards generated by an atomizer.The particle size distribution of the generated monodisperse aerosol in the corresponding size range measured by the Dust Particle Counter is 92%,the requirment of methods of testing the performance of dust particle counter-calibration for sizing particle is 60%,the technique is a very useful tool to improve the measurement accuracy of the Dust Particle Counter.

The idea of calculating plutonium isotopes ratio using Pu600 energy window (630-670 keV) was put forward by the LLNL .And plutonium isotopes ratio arithmetic on Pu600 energy window was developed in this paper .Some γ energy spectra of two plutonium samples were calculated on this arithmetic ,and the results are consistent with the results from PC/FRAM .

The main features,research status and application of High Pressure Xenon Gamma detector are introduced in the paper.HPXe detector is steady when working in the temperature ranging from 20 ℃ to 200 ℃.Furthermore,it is of great resistance to radiation.In room temperature detectors,HPXe provides better energy resolution than NaI(Tl),LaBr,BGO and CZT.With the increasingly development of study of HPXe detector,a series of key problems have been resolved,such as proportion of H2 in Xe + H2 mixture,work pressure,work voltage and structure of detector.HPXe detector is promising to be used in the fields of space Gamma detection,nuclear safeguard and environment monitor.

In this paper, we study the amount and size distribution of aerosol particles formed in an explosion in a sealed metal container in presence of a silver sample.Aerosol samples were collected for different minutes at different time after the explosion.The samples were weighed, and examined by neutron activation analysis, scanning electron microscopy and X-ray diffraction.The results indicated that changes in size distribution of the particles depended on the process combining Brown aggravation and gravitation sedimentation in the container.The aerosol particle size in relatively stable gas phase distributed mainly around 1.8 μm.The Ag particles had a segregating behavior in particles of different sizes.Most Ag aerosol particles under 10 μm size consisted of small polycrystalline aggregates, and the average crystalline size was 27.3 nm.

A new method for arms control inspections of metal plutonium has been developed.It measures the 478 keV γ ray from 10B(n, α) 7Li reaction by neutrons generated in spontaneous fission of 240Pu in metal plutonium being inspected.In this work, simulations were performed for the converting and transporting process of neutron-photon, and adjusting parameters of the 10B target, including the 10B content of the target, thickness of the target, and the geometry parameters, in an attempt to optimize the converting efficiency.The results show that the method could be achieved detection efficiency of gamma yield of 10?5 per neutron, which allows the detection of kilogram of weapon-grade metal plutonium.

The atomic and molecular reaction dynamics for Si（1Dg）+H2（0，0）and H（2Sg）+SiH（0,0） have been studied on the potential energy function SiH2（X1A1） by Monte-Carlo quasi-classical trajectory approach.It is shown that the reaction Si（1Dg）+H2（0，0）has no threshold energy，and the principal product of this reaction is SiH2（X1A1）.However, the reaction H（2Sg）+SiH （0,0） gives a great number of products of the interchange reaction of H（2Sg）+SiH （0,0）→Si（1Dg）+H2（0，0），and it has also no energy threshold.

When using a large area rectangular plastic scintillator to detect γ,the efficiency of detection varies with the distance from the γ incidence point to the signal collection point.The detection efficiency is lower when the distance is longer.For resolving this problem,a new measurement for high detection efficiency is studied in our work.We collect signals from two different ends of the rectangular plastic scintillator at the same time,and use a summator to add the two signals together.With this method,the detection efficiency is apparently enhanced.

Location of gamma spectral peak is critical for spectrum analysis.Basic characters of first-order,second-order and third-order differential gamma spectrum at spectral peak are studied.Compound peaks which are combinations of two more peaks,and simulated by different peak span or amplitude according to superposition are analyzed by differential method.The analysis result shows that third-order differential method is better than the other two for discriminating Compound peaks.On the basis of the discussion above,locationing algorithm combined with statistical criterion about presence of a peak is introduced,which can discriminate all real peaks and get rid of false peaks.Furthermore,the computer program according to this algorithm is built to search gamma spectral peaks.The result shows that the program is excellent for locating gamma spectral peaks.

The principle of alarm in the course of nuclear monitoring is introduced. The false alarm probability is de- fined. The alarm false probability of the nuclear monitoring system in a nuclear storeroom was calculated and meas- ured experimentally under different alarm thresholds. Origin of the difference between the calculated probability and the measured probability was analyzed.

LLNL bring forward an arithmetic of the plutonium age with the 330-350keV(Pu300) energy window. And another arithmetic of plutonium age with the same energy window is proposed in this paper. The ages of two plutonium samples were calculated with this arithmetic, and the comparison with the results from PC/FRAM indicates that the proposed arithmetic is rather reasonable.

在军控核查研究气体在环境中的沉积、扩散等的项目中,为寻找1种气体核素示踪方法,本工作对放射性气体核素127Xe的制备方法进行研究.在反应堆中对盛装在玻璃管中的普通氙辐照96 h,经一定时间冷却后,将辐照产物吸附到处于液氮温度下的特制源盒中,20 min后,待Xe气体在源盒中达到均匀分布再进行γ能谱测量,以获得127Xe的准确活度值.实验结果证实,应用上述方法制备放射性气体示踪核素127Xe是可行的.

A new method is established for measuring nuclear fission number. In this method, the gamma ray total counts of 3-5MeV energy region is utilized. In this paper, the feasibility of this method is verified by irradiation experiment of enriched uranium sample. The results show that this method can be used to measure number of nuclear fission. Compared with the result of general method, the uncertainty in the measurement of this method is less than 16%. It is of worth-while further research.

In order to study the gas deposition and diffusion in environment, the preparation process of radioactive gas 127Xe as a new gas tracer is investigated. The ordinary xenon was filled in glass tubes and irradiated for 96 h in nuclear reactor. The irradiation products was transported into a special source box filled with activated charcoal at liquid nitrogen temperature. When the equilibrium distribution of gas Xe in the source box is achieved, the γ-spectrum was continuously acquired. The experimental result shows that the present 127Xe preparation process is feasible.

MCNP programme can be used to simulate detection efficiency of high pure germanium de tector that measures a volume source at certain position from. However, Mathematics model of detector and source cannot be established perfectly, so the result of calculation has some error. To get accurate calculation result, the result must be corrected, In this work, we have considered various factors that influence the result, and established an expression to correct the calculation result, and then, compared the calculation result after correction with experiment result and result of the other programme (ISOCS). we cancluded that MCNP programme is efficient way to simulate the detection efficiency of the volume source by correction.