蒸汽发生器主蒸汽管道16N传输时间的分析与计算

利用监测二回路主蒸汽管中^16N辐射来实现蒸发器传热管破损在线检测是一种直接而有效的方法;主蒸汽管道^16N传输时间的计算是在线检测系统的关键技术之一。分析了传热管发生泄漏时的^16N放射性核素迁移过程,对^16N传输时间的计算原理和方法进行了探讨,并以“陆奥”船用核动力装置为例,计算了三种情况下传热管发生泄漏时^16N的传输时间。     

16Nγ辐射监测仪的研制

^16Nγ辐射监测仪主要分探测器和电子学仪器两部分。将探测器安装在蒸汽管道旁，由所探测到的γ射线计数率和温度信号，通过智能化软件经电子学仪器处理可直接显示蒸汽发生器内u形管的泄漏率，具有自动报警的功能。所制成的探头符合防水、隔热、抗电磁干扰、抗强震动的要求。电子学仪器：集约化、智能化程度高，重量轻。本装置与法国产的^16N监测仪进行了比对，结果在误差范围内符合。经现场的测试表明：本装置长期稳定性好，检测灵敏度高，故障率低，操作使用方便。     

SCAS-蒸汽活化产物源项程序的开发和验证

SCAS是中国核动力研究设计院编制的反应堆二回路蒸汽活化产物源项程序。为了使SCAS程序同时具有计算主回路冷却剂中^16N和^17N源项的功能，特建立了两种不同的几何模型，并以两种不同的方式验证了程序的可靠性。结果表明，SCAS程序不仅能用于计算无堆芯系统二回路工质中^16N,^17N的源项。还能计算含堆芯系统主回路冷却剂中的^16N,^17N的源项。     

基于14 MeV μs脉冲中子发生器与NaI(Tl)和BGO闪烁探测器的爆炸物检测系统的研制

介绍了利用14MeV μs脉冲中子发生器、NaI(Tl)和BGO闪烁探测器建立的爆炸物检测实验系统。研究了中子感生瞬发γ能谱的时间特性，分别测量了快中子的非弹性散射γ能谱和热中子辐射俘获γ能谱。使用了NaI(T1)和BGO两种探测器测量γ能谱；NaI(Tl)探测器在测量“N的热中子辐射俘获γ10、835MeV时表现出了很好的性能，而BGO探测器则在测量^12C和^16O的快中子非弹性散射γ时得到了较好的结果。利用这两种探测器测量了22种样品，其中包括RDX、TNT、NQ3种炸药。根据NaI(Tl)和BGO测量到的中子感生瞬发γ能谱，在分析了^1H、^12C、^14N、^16O的元素含量之后，有效地实现了对炸药与普通物品的分辨。     

甘肃饮用水源地水体辐射环境在线自动监测系统总体设计

以甘肃省辐射监测网络建设为契机,在我国首次建立了覆盖全省重要饮用水源地的在线监测系统,对水中总α、总β、~3H及~(90)Sr进行实时监测预警。系统通过创新水体在线辐射监测技术和应用理念,配合合理的站点布局、网络规划和软件设计,实现了对甘肃全省水体辐射安全数据的全面掌握,保障饮用水安全,为未来水体辐射安全监管能力建设提供可参考的新模式。     

钍矿石选矿在线测量系统构建

介绍了一种由阵列式数字化γ辐射探头组成的钍矿石选矿在线测量系统。探测器采用NaI(Tl)晶体,通过脉冲放大、滤波成形和单道脉冲幅度甄别等电路输出数字矩形脉冲,构成单路数字化γ辐射探头。钍矿石依次经过十路探头,探头产生的脉冲计数和作为矿石筛选依据,由FPGA实现十路计数器、求取计数和以及与上位机串行通信,上位机软件采用Python语言编写,具有实时显示钍矿石含量、异常报警、参数调整和输出保存等功能。经测试,系统运行稳定可靠,可满足实际工作需要。     

一种采用TIM测量原理的智能探头在环境γ辐射监测中的测量和报警统计特性

芬兰RADOS公司研制的RD-02型智能探头，是一种用GM计数管作传感器、用脉冲时间间隔法（TIM）监测γ、χ辐射剂量率的探头。本文着重对这种智能探头在环境γ、χ辐射剂量率监测中的测量和报警统计特性作了分析计算，并指出了该探头用于环境γ辐射剂量率监测时应当注意的几个问题。本文还建议在核辐射测量及其应用方面对采用时间间隔法予以关注和研究。     

西安脉冲堆辐射剂量监测

为了确保反应堆运行人员和公众的安全，西安脉冲堆设置了比较完善的辐射剂量监测系统。该系统包括固定式在线连续监测和便携式仪表及取样监测两部分，本文主要了固定式在线连续监测的监测,测点布置以及各监测仪的性能特点，并简要介绍了便携式仪表及取样监测中各仪表的性能与适用范围。     

一种新型的光致荧光辐射剂量计的研究

光致荧光辐射剂量实时在线探测技术,主要利用掺杂两种稀土元素的碱土金属硫化物的光致荧光特性,将材料制成薄片,通过光致荧光剂量片存储辐射剂量,探头和光纤置于辐射场中,激发光源通过光纤传到探头,用灵敏的光探测装置读出荧光片中存储的辐射剂量,获得一种新型的在线辐射剂量测量技术.该技术测量范围宽、灵敏度高;存储的辐射剂量用内部光源照射清除,设备相对简单、体积小、功耗低.此测量仪器很适合空间在线实时辐射剂量探测,另外还可以用于集成电路辐射以及高辐射剂量等危险场合辐射剂量的测量,具有良好的应用前景.     

基于控制器局域网络的γ辐射监测系统研制

基于控制器局域网络(CAN)总线设计了网络化辐射监测系统。监测系统以盖革-米勒计数管(简称G-M管)作为γ射线探测器,采用CAN总线的通信方式实现数据传输的可靠性。整个系统采用模块化设计,可扩展性强,能够实现对γ辐射剂量的在线实时监测。     

Development of a direction finding gamma-ray detector

This paper describes a direction finding gamma-ray detector, which consists of three different scintillators; NaI (Tl), CsI (Tl) and BGO. The detector positively increases directional sensitivity to incident gamma-rays, and can measure direction, energy and number of gamma-rays. This detector will be useful to carry out monitoring of nuclear power plants or radiation facilities in emergencies. It will be also effective in searching for radiation sources such as radioisotopes and radioactive contaminations. Experimental results have shown the proposed directional detector has a potential for practical use in real fields and will contribute to radiation emergency preparedness.     

HPXe γ探测器的研究与应用

介绍了HPXe探测器的特性、研究现状和应用前景。HPXe探测器可以在20～200°C的环境温度下稳定工作,也可以在强辐射环境下工作。在常温探测器中,HPXe探测器的能量分辨本领要优于NaI(Tl)、LaBr、BGO、CZT等探测器。HPXe探测器的研究工作已经比较深入,探测器设计中的一些关键问题,例如组分气体的比例、气体的压力、工作电压以及探测器的结构等已经得到解决。HPXe探测器在宇宙γ射线测量、核安全监测以及环境监测等方面有着很广阔的应用前景。     

核电厂运行现场高能γ射线的剂量调查

在核电厂正常运行期间,反应堆冷却剂系统内存在能够发射高能γ射线的¹⁶N等放射性核素。为了初步掌握核电厂运行期间不同区域内高能γ射线的辐射水平,利用NaI(Tl)谱仪在国内某核电站测量了反应堆厂房内的γ能谱,并根据γ测量谱和测量系统的响应函数计算了能量大于3 MeV的γ射线的场所剂量率。结果显示:在15个测量位置中,6个位置的γ测量谱中存在明显的高能成分,其对应的剂量率在1.02～30.14 μSv/h范围内。     

脉冲中子全能谱测井闪烁探测器响应特性的蒙特卡罗模拟

利用蒙特卡罗方法模拟研究NaI和BGO晶体探测器对不同γ射线的响应。模拟结果表明，BGO晶体的光电峰和第一逃逸峰对计数贡献大，而NaI晶体的逃逸峰贡献大。对于井眼和地层流体分别为油和水砂岩地层，模拟改变NaI和BGO晶体探测器的直径和长度时的非弹性散射γ射线响应能谱，采用不同能窗处理方法对地层流体的分辨能力不同，选取光电峰和第一、第二逃逸峰对应的能量窗时，BGO晶体探测器比NaI晶体探测器测量的C/O（C与O的元素含量比）差值大，但受尺寸的影响不大；采用光电峰对应的能量窗时，BGO晶体探测器测量的C/O差值比NaI的大得多，且随尺寸的增加差值增大；能量道的漂移对C/O值影响较大，而能量分辨率对差值影响相对较小。     

Production of 16N and obtaining of its gamma spectrum in order to calibrate detectors or determination of fluorine in geological specimens

In this paper, we show a procedure for producing ¹⁶N and a method to obtain its gamma spectrum with a NaI(Tl) detector. We also demonstrate the interest of this radioactive element for the purpose of NaI(Tl) detector calibration and for the determination of fluorine in geological specimens using an Alpha Beryllium neutron source.This work consists of a theoretical study which analyzes the characteristics of ¹⁶N and nuclear reactions that originate from an Americium Beryllium source of 1Ci activity. We justify our choice of reaction ¹⁹F(n,α)¹⁶N and the use of fluorspar as a source of fluorine.The mathematical procedure followed to obtain the gamma rays spectrum produced by ¹⁶N in a NaI(Tl) detector is shown.     

脉冲中子全能谱测井数据处理方法及影响因素的模拟研究

C/O能谱测井是确定含油饱和度的主要测井方法,模拟水平井条件下的非弹性散射伽马能谱,研究C/O值与含水饱和度、孔隙度及泥浆侵入深度的关系。而探测器的类型、尺寸、探测效率、能量分辨率、稳谱、能谱的处理方法以及中子对探测器晶体的作用都会对测井结果产生影响。利用蒙特卡罗方法模拟源距分别为30cm和58cm处,且井眼和地层流体分别为油和水砂岩地层的中子能量分布,通过研究中子对NaI、BGO、GSO和LSO四种探测器的作用及响应关系得到：中子对探测器的作用将使地层流体分辨能力降低。模拟改变NaI和BGO晶体探测器的直径和长度时的探测器响应能谱,采用不同的能窗处理方法对地层流体的分辨能力不同,选取光电峰和第一、第二逃逸峰对应的能量窗时BGO晶体探测器测量的C/O差值要比NaI晶体探测器的大,但受尺寸的影响不大;但采用光电峰对应的能量窗时,BGO晶体探测器测量的C/O差值要比NaI大得多,且随着尺寸的增加差值也增加。能量道的飘移对C/O值影响较大,而能量分辨率对差值影响相对较小     

Cerium-doped lutetium oxyorthosilicate: a fast, efficient newscintillator

The authors discuss a single-crystal inorganic scintillator, cerium-doped lutetium oxyorthosilicate (Lu_2(1-x)Ce_2x (SiO₄) or LSO). It has a scintillation emission intensity which is ~75% of NaI(Tl) with a decay time of ~40 ns. The peak emission wavelength is 420 nm. It has a very high gamma-ray detection efficiency due to its density of 7.4 g/cm³ and its effective atomic number of 66. Its radiation length of 1.14 cm is only slightly longer than bismuth germanate (BGO). The scintillation properties of Ce-doped LSO are compared to NaI(Tl), BGO, and cerium-doped gadolinium oxyorthosilicate (GSO). In addition to desirable physical properties such as high density and high atomic number, LSO also processes a combination of high emission intensity and fast decay which together are superior to any other known single crystal scintillator     

Use of a Gain Stabilized NaI(T1) Gamma Ray Detection System to Determine the Power Shape in Light Water Reactor Cores

A data acquisition system which consists of a NaI(T1) detector, associated electronics and a disc-based minicomputer has been used to obtain accurate relative gamma ray intensities over a large range of count rates (up to ~250 kHz) from light water reactor fuels. The system uses a green light-emitting diode optically coupled to the photomultiplier face to insure gain stabilization over a variation of count rates and environmental conditions, and to determine empirically the pileup and dead-time losses. The energy resolution of NaI(T1) is adequate for this application because only the well-isolated 1.6 MeV gamma from La-140 is used to relate fission product activity to power. Measurements have been performed on irradiated fuel during refueling outages at both boiling and pressurized water reactor (BWR and PWR) nuclear power plants.     

Imaging Properties of a Positron Tomograph with 280 Bgo Crystals

The basic imaging properties of the Donner 280-BGO-Crystal positron tomograph were measured and compared with the same system when it was equipped with 280 NaI(T1) crystals. The NaI(T1) crystals were 8 mm × 30 mm × 50 mm deep, sealed in 10 mm wide stainless steel cans. The BGO crystals are 9.5 mm wide × 32 mm × 32 mm deep and as they are not hygroscopic do not require sealed cans. With a shielding gap of 3 cm (section thickness 1.7 cm FWHM) the sensitivity of the BGO system is 55,000 events per sec for 1 ?Ci per cm3 in a 20 cm cylinder of water, which is 2.3 times higher than the NaI(T1) system. For a 200 ?Ci/cm line source on the ring axis in a 20 cm diameter water cylinder, the BGO system records 86% of the scatter fraction and 66% of the accidental fraction of the NaI(T1) system. The lower light yield and poorer time resolution of BGO requires a wider coincidence timing window than NaI(T1); however, the ability to use full-energy pulse height selection with a 2.3-fold improvement in sensitivity results in an overall reduction in the fraction of accidental events recorded. The in-plane resolution of the BGO system is 9-10 mm FWHM within the central 30 cm diameter field, and the radial elongation at the edge of the field in the NaI(T1) system has been nearly eliminated.