Radiophotoluminescence phenomenon in copper-doped aluminoborosilicate glass

Radiophotoluminescence phenomena have been widely investigated on various types of materials for dosimetry applications. We report that an aluminoborosilicate glass containing 0.005 mol% copper exhibits intense photoluminescence in the visible region induced by X-ray and γ-ray irradiation. The luminescence is assigned to the 3d⁹4s¹ → 3d¹⁰ transition of Cu⁺. The proportionality of the intensity of the induced photoluminescence to the irradiation dose was confirmed up to 0.5 kGy using ⁶⁰Co γ-ray irradiation. Based on the spectroscopic results, a potential mechanism was proposed for the enhancement of the photoluminescence. The exposure to the ionizing radiation generates electron-hole pairs in the glass, and the electrons are subsequently captured by the Cu²⁺ ions, which are converted to Cu⁺ and emit the luminescence. For the glass containing 0.01 mol% copper, the pronounced enhancement of the photoluminescence was not observed because the reverse reaction, ie, the capture of the holes by the Cu⁺ ions, becomes prominent. The photoluminescence induced by the irradiation was stably observed for the glasses kept at room temperature and even for the glasses heat-treated at 150°C. However, the induced photoluminescence could be eliminated by the heat treatment at a temperature at 500°C, and the glass returned to the initial pre-irradiation state. The Cu-doped aluminoborosilicate glass is a potential candidate for use in dosimetry applications.     

热释光探测器在脉冲硬X射线能谱测量中的应用

介绍了TLD－3500热释光读出器和GR－100M型热释光剂量片构成的探测器在脉冲硬X射线辐射参数测量中的应用。详细论述了采用滤波荧光法与热释光探测器相结合测量10－10keV的硬X射线能谱的物理思想，在综合考虑了测量环境的具体情况下，设计研制了硬X射线测量系统，建立了热释光探测器对硬X射线绝对能量响应的标定方法。该方法已成功用于脉冲辐射装置“强光1号”的测量，并得到了实测数据。     

Synthetic single crystal diamond dosimeters for Intensity Modulated Radiation Therapy applications

A synthetic single crystal diamond Schottky diode, in a p-type/intrinsic/metal structure, deposited by Chemical Vapour Deposition (CVD) and operating in photovoltaic regime, with no external bias voltage applied, was tested as a dosimeter for Intensity Modulated Radiation Therapy (IMRT) applications. The device response was compared with dose measurements from two commercial ionization chambers and a 2D diode array in an IMRT prostate cancer treatment plan. The obtained results indicate that CVD synthetic single crystal diamond-based dosimeters can successfully be used for highly conformed radiotherapy and IMRT dosimetry, due to their small size and high sensitivity per unit volume.     

Use of Bromocresol Green Dyed Poly(Vinyl Butyral) Film for Dosimetric Applications

A system consists of a poly(vinyl butyral) film containing acid-sensitive dye, bromocresol green (BCG), in presence of chloral hydrate has been investigated as a radiation-sensitive indicator. The acid-sensitive dye in the film changes its color from blue to yellow by irradiation due to the consequent lowering of the pH of the film caused by HCl generated from the radiolysis of Cl-containing substance. This film can be used as a dosimeter in a relatively low dose range up to 6 kGy. The radiation chemical yield (G-value) of films was calculated, where it increases with increase of both concentration of bromocresol green film and concentration of chloral hydrate. This response range makes this system useful in some food irradiation applications. The effects of humidity during irradiation and post-irradiation storage on the response of the film are discussed.     

影响热释光剂量计定度系数的因素

介绍了ＴＬＤ定度系数的三种影响因素,并指出剂量传递法定度ＴＬＤ的定度系数,可以使ＴＬＤ测量剂量的相对误差控制在±５％。     

Gamma radiation levels in the ambient environment of the QNPP Base

Monitoring results of gamma dose rate level in 1992～2004 in the ambient environment of the Qinshan Nuclear Power Plants(QNPP)Base,the northeast of Zhejiang Province,are reported in this paper.It is shown that the gamma dose rate of five monitoring sites of 2.5 km to QNPP Base is 84～113 nGy/h,with an average of 96 nGy/h in the 13 years.The average value is close to the background level of 93 nGy/h prior to operation of the QNPP Base,and is lower than the monitoring result of 101 nGy/h at the reference site in Hangzhou City.Within 50 km from the QNPP Base,the cumulative dose rate of the thermoluminescent dosimeter(TLD)is 90 nGy/h,which is lower than the back- ground level of 111 nGy/h.     

葡萄糖-氯化钠晶溶发光剂量计研究

利用化学方法来测量混合场中的n、γ成分已有很多方法。其中,氯代烃体系较为普遍,但方法复杂,对器皿和试剂以及操作要求都比较高;四氯乙烯化学剂量计体系则不能用于500rad以下的测量;含硼与不含硼的硫酸亚铁体系也只能测量较高剂量。测量混合场中D_n、D_γ的方法多是使用“对”剂量计,即其中一个体系对中子不敏感而另一个体系对中子和γ射线都敏感的原理来测量。其计算D_n和D_γ公式为:     

ALANINE/ESR DOSIMETRY FOR MEASUREMENT OF ELECTRON DOSES IN INDUSTRIAL APPLICATIONS

In this report, the results of preliminary research on L-alanine/ESR electron dosimeters are described. They include the designs of modelling tools and experimental capsules, the preparation and irradiation of very thin dosimeters, the measurement of ESR signal spectrum and the calibration method. The physical, chemical and dosimetric properties of the alanine free radical dosimeters, such as the smallest thickness, average density, lowest detectable limit, repeatability of the method, reproducibility resulted in directivity and location in resonance cavity, linearity regions as well as relative scattering of the response to identical doses, are summarized.     

辐射变色薄膜剂量计

近年来,由于辐射加工、辐射食品保鲜和贮藏、辐射消毒和辐射杀菌等得到广泛应用,高剂量的测量技术日益被人们重视。 国际上关于高剂量计的比对工作于1977年、1978年、1980年连续进行了三次,主要采用的剂量计有四种,即α丙氨酸剂量计、硫酸铈剂量计、热释光剂量计和辐射变色薄膜剂量计。在这些比对试验中,其误差均在10％左右。