热释光剂量学的研究、现状及发展

系统地介绍了热释光剂量学的发展历史,有关研究热释光剂量计的内容及其热释光剂量学有史以来所研究出的热释光材料的剂量学特性,同时也提出了热释光剂量计的固有的问题。     

Comparisons of dosimetric properties between GD-300 series of radiophotoluminescent glass detector: and GR-200 series of thermoluminescent detectors

In order to compare the dosimetric properties of two kinds of solid state detectors used for monitoring external exposures,experiments Were performed for the GD-300 series of radiophotoluminescent glass detectors (RPLGD) and the GR-200 series of thermoluminescent detectors (TLD).X-rays and 137 Cs and 60 Co γ-rays were used to irradiate the RPLGDs and TLDs,their dose linearky,uniformity/reproducibility of signal,fading effect and energy dependence were compared.Both kinds of the detectors have generally good dosimetric properties.The dose linearity and energy dependence of the GD-351 dosimeters and the TLDs are nearly the same,but the RPLGD is much better than the TLD in terms of the uniformity and fading effect.     

A mathematical method to calculate efficiency of BF3 detectors

In order to calculate absolute efficiency of the BF3 detector, MCNP/4C code is applied to calculate rela-tive efficiency of the BF3 detector first, and then absolute efficiency is figured out through mathematical techniques. Finally an energy response curve of the BF3 detector for 1~20 MeV neutrons is derived. It turns out that efficiency of BF3 detector are relatively uniform for 2~16 MeV neutrons.     

Restricted energy loss of ultrarelativistic particles in thin targets - A search for deviations from constancy

Experimental results for the restricted energy loss of ultrarelativistic electrons, with Lorentz factors up to 3×10⁵, in a thin silicon detector are presented. The combination of high Lorentz factors and thin targets, opens for the possibility to study two mutually excluding effects, both based upon theory and on scarce experimental observations. One is a disappearance of the density effect when the transit time becomes so short that the effect of plasma-oscillations becomes negligible. This would result in an increased energy loss as the Lorentz factor increases. The other is an effect based on the existence of a coherence length over which there are contributions to the energy loss. This effect leads to a substantially decreased energy loss for thin targets as the Lorentz factor increases. The latter is shown to be incompatible with our measurements, whereas the former may be present with a correction of a few percent to an otherwise constant energy loss. Furthermore, we point to significant effects related to synchrotron and transition radiation, that must be carefully considered in a possible future experiment, and may as well have been of significance for the conclusion in earlier experiments.     

Collimated LaBr3 detector response function in radioactivity analysis of nuclear waste drums

The properties of a Lanthanum bromide （LaBr3） detector and its response functions were investigated via experiments and simulations in this paper. The LaBr3 detector had good relative energy resolution and higher efficiency than a high-purity germanium detector. Monte Carlo and other numerical methods were used to calculate the efficiencies of a LaBr3 detector with a square collimation window. A model of the numerical method was established based on a pure geometric model that was consistent with the experimental situation. The results showed that the detector response functions calculated by these methods were in great agreement with experimental results.     

Gd2 SiO5:Eu3+ 的VUV-UV光谱特性

本文介绍了利用同步辐射光源对Gd2SiO5:Eu^3 的VUV－UV光谱特性进行的研究。重点讨论了在低温（10K）及室温下Gd2SiO5:Eu^3 中存在的各种能量传递过程，包括基质向Eu^3 ,Gd^3向Eu^3 的传递以及两种不同格位Eu^3 离子之间的能量传递。另一方面从探索新型量子剪裁材料的角度对比了186nm和276nm激发下的发射谱，指出Gd2SiO5:Eu^3 中可以发生有效的量子剪裁。     

绵阳地区近地面气溶胶中7Be和210Pb分布特征及其对O3的示踪

为了解绵阳地区近地面空气中辐射环境质量状况,掌握其变化趋势,探索近地面气溶胶物质来源及其对近地面O₃浓度示踪意义,对绵阳安州区、江油市、梓潼县和平武县2018年3月至2019年2月气溶胶样品进行详细的γ能谱分析。总体上,⁷Be的活度浓度在春、秋季节较高,而夏季最低,年平均值为1.90～2.13 mBq/m³,与全球内陆、中纬度和低海拔地区分布特征基本一致;²¹⁰Pb的活度浓度全年呈现为“U”型分布特征,年平均值为1.24～1.66 mBq/m³,为全球陆地上²¹⁰Pb活度浓度的相对高值。通过近地面气溶胶中⁷Be、¹⁰Pb和⁷Be/²¹⁰Pb比值与O₃相关性分析及P值检验表明:气溶胶中⁷Be/²¹⁰Pb比值与近地面O₃为非常显著正相关关系,能作为近地面空气中O₃来源的良好示踪指标;绵阳地区梓潼县和平武县近地面空气中O₃来源受大气垂直对流活动影响较大。     

Study on explosion characteristics of natural gas and methane in semi-open space for the HTTR hydrogen production system

It is important to grasp the explosion characteristics of object gases: natural gas and methane, in order to evaluate the influence of a gas explosion accident in the HTTR hydrogen production system on the reactor. Thus, we carried out explosion experiments of the object gases in semi-open space, and verified a numerical analysis code for the simulation of the explosion accident. It was confirmed that NG–air mixture or methane-air mixture in semi-open space did not result in DDT although 10 g of C-4 explosive was used as an ignition source, and the numerical results agreed relatively with the experimental results. As a result, we could have the prospects for predicting the influence of the explosion accident on the reactor.     

Energy dispersive X-ray fluorescence analysis of ancient coins: The case of Greek silver drachmae from the Emporion site in Spain

Greek colonizers arrived at the Iberian Peninsula at the beginning of the sixth century B.C. and founded a small colony known as Emporion in north-east Spain. By the fifth century B.C., this colony became a small polis with a well-organized administrative structure. In this context, the necessity of coinage was a fact and the first coins were minted [1]. Some of these coins were characterized by using energy dispersive X-ray fluorescence equipment. The analytical study focused on the elemental characterization of the coins minted from the fourth century to the first century B.C. and their compositional evolution during this period. The investigation has pointed out a very high fineness of the alloys throughout the time, with an average silver content around 98.32%, and the feasibility of energy dispersive X-ray fluorescence as a screening tool for the characterization of the alloys.     

尖晶石－石榴石相转变过程中矿物的微量元素组成与分布特征

利用质子微探针和微束ＰＩＸＥ定量分析技术对山东梭罗树地慢橄榄岩中橄榄石、斜方辉石、单斜辉石、尖晶石和石榴石等矿物的微量元素组成与分布进行了研究。结果表明，不相容元素（Ｓｒ、Ｙ、Ｚｒ）主要富集于单斜辉石内，尖晶石则几乎富集质子探针所能检出的所有微量元素，而石榴石中微量元素含量最少。该研究表明，在矿物微区微量元素分布是十分不均匀的，推测可能受地幔交代过程中溶液的渗滤效应以及存在微粒包裹体的共同制约。     

Formation of spectral characteristics of channeling radiation from 800 to 2000 MeV electrons and positrons in a thin silicon crystal

The influence of the tails of particle trajectories on planar channeling radiation (CR) spectra from relativistic (800-2000 MeV) electrons and positrons in a thin silicon crystal is investigated. It is shown that the trajectory tails significantly change the CR spectra from electrons and positrons in specific parts of the spectra compared to calculations which do not take into account this effect.     

Capabilities of TRANSURANUS code in simulating power ramp tests from the IFPE database

Investigations of fuel behavior are carried out in close connection with experimental research, operation feedback and computational analyses. OECD NEA sets up the “International Fuel Performance Experiments (IFPE) database”, a public domain database on nuclear fuel performance experiments with the purpose of model development and code validation. The objective of the activity (performed in the framework of the IAEA CRP FUMEX-III project) is to investigate the pellet-clad interaction mechanism and the capability of TRANSURANUS code in simulating the phenomena, processes occurring in the fuel rod during the power ramps, with focus on the parameters influencing the cladding failures. The experimental database adopted is the Studsvik PWR Super-Ramp subprogram, part of the IFPE database, which consists of 28 pressurized water reactor fuel rods power ramped at burnup from 28 to 45 MWd/kgU. Relevant results by TRANSURANUS are presented in connection with the experimental evidences. Focus is given on the PCI/SCC failure, demonstrating that the failure threshold, available in TRANSURANUS, results conservative both in case of KWU and W rods.