Study of the ultraviolet emission of the electrode coatings of arc welding

The optical emission properties of several minerals components employed in electrode coatings of arc welding have been investigated. The X-ray diffraction analysis shows that the composition of 14 commercial electrode coatings collected from different countries (Spain, France, UK, Poland, Argentina and Germany), consists of quartz, calcite, sodium and potassium rich feldspars, muscovite and rutile. The natural thermal stimulated luminescence (TSL) of these mineral phases, measured in the range of 200-800 nm at different temperatures (from room temperature to 400 degrees C) displays UV-A (wavelengths of 320 nm to 400 nm) and UV-B (from 280 nm to 320 nm) emissions, with the exception of rutile. The UV-B radiation, commonly described as the most dangerous form of radiation to human life, is here associated with structural defects in the crystallographic lattice of the mineral components of electrode coatings.     

电离辐射剂量监测用热释光探测器

用固体能带（晶格能级）理论阐述了热释光探测用于剂理测量的机制；介绍了热释光探测器常用的５种磷光体，即ＬｉＦ，ＣａＳＯ４，ＣａＦ２，Ｌｉ２Ｂ４Ｏ７和ＢｅＯ的剂量学特性及其优缺点和使用中应注意的问题；给出了热压挤片法、热压切片法、冷压烧结法、毛细管封装法和树脂粘合法等热释光探测器的制备工艺，以及它们的适应范围。     

The response of the thermoluminescent dosimeter CaF2:Tm to protons in the energy range 15–30 MeV

This study describes the response of the thermoluminescent dosimeter CaF₂:Tm to protons from a compact cyclotron with energies between 15 and 30 MeV. Glow curve analysis indicates that the response of CaF₂:Tm to protons depends on proton energy and proton current.     

Luminescent Afterglow Behavior in the M2Si5N8: Eu Family (M = Ca,Sr, Ba)

Persistent luminescent materials are able to emit light for hours after being excited. The majority of persistent phosphors emit in the blue or green region of the visible spectrum. Orange- or red-emitting phosphors, strongly desired for emergency signage and medical imaging, are scarce. We prepared the nitrido-silicates Ca₂Si₅N₈:Eu (orange), Sr₂Si₅N₈:Eu (reddish), Ba₂Si₅N₈:Eu (yellowish orange), and their rare-earth codoped variants (R = Nd, Dy, Sm, Tm) through a solid state reaction, and investigated their luminescence and afterglow properties. In this paper, we describe how the persistent luminescence is affected by the type of codopant and the choice and ratio of the starting products. All the materials exhibit some form of persistent luminescence, but for Sr₂Si₅N₈:Eu,R this is very weak. In Ba₂Si₅N₈:Eu the afterglow remains visible for about 400 s, and Ca₂Si₅N₈:Eu,Tm shows the brightest and longest afterglow, lasting about 2,500 s. For optimal persistent luminescence, the dopant and codopant should be added in their fluoride form, in concentrations below 1 mol%. A Ca₃N₂ deficiency of about 5% triples the afterglow intensity. Our results show that Ba₂Si₅N₈:Eu(,R) and Ca₂Si₅N₈:Eu(,R) are promising persistent phosphors for applications requiring orange or red light.     

吉林省放射工作人员个人外照射剂量水平的调查

本文报道了用热释光方法监测的3326例放射工作人员所接受的年剂量水平。年剂量最少者为O.1mGy,最大者为58.4mGy,均值为1.68mGy.按职业分类, 牙科射线照相人员为2.44mGy,工业射线探伤人员为2.12mGy,放射诊断人员为1.76mGy,核医学工作人员为1.13mGy,研究人员为0.97mGy,放射治疗人员为0.67mGy,3326例中96.4%的放射工作人员年受照剂量低于放射工作人员年剂量当量限值的十分之三, 90.1%的人员低于十分之一。     

Lu2O3:Pr,Hf Storage Phosphor: Compositional and Technological Issues

Lu₂O₃:Pr,Hf ceramics were investigated using mainly thermoluminescence (TL) technique. Their ability to efficiently store energy acquired upon irradiation with X-rays was proven. The best TL performance was achieved for compositions containing 0.025%–0.05% of Pr and about 0.1% of Hf. Further enhancement of TL efficiency was attained by increasing the temperature of sintering of the ceramics up to 1700 °C and applying reducing atmosphere of forming gas. It was also proven that fast cooling after the sintering at 1700 °C significantly enhanced the storage phosphor performance. TL glow curve contained three components peaking around 130, 250 and 350 °C. Among them, the one at 250 °C contributed the most to the total TL.     

监测受检者入射体表剂量的热释光方法的质量保证

[目的]为保证医疗照射剂量监测结果的可靠性,开展热释光剂量（thermoluminescence dosimetry,TLD）方法的质量保证研究。[方法]在次级标准剂量学实验室进行TLD的分散性、剂量线性和能量响应特性实验;通过建立标准化退火和测量程序并对设备进行定期校正来控制监测质量。[结果]经分档后各档TLD的灵敏度差异〈4％;在0．3～20mGy的剂量范围内,所用TLD具有理想的剂量线性（R^2=0．9999）;在医用诊断X射线常见的能量范围内,所用TLD的能量响应变化〈1．0％;盲样测量结果表明,TLD的测量值与约定真值偏差在-2．55％～0．12％之间。[结论]通过加强TLD的质量保证,可以有效提高x射线诊断受检者入射体表剂量监测结果的可比性和准确性。     

手表红宝石热释光剂量学某些特性的进一步研究

在改进的手表红宝石事故剂量测读装置上，对不同种类、不同型号的手表红宝石热释光剂量学特性，尤其是照射后衰退性做了进一步研究．对其热释光发光曲线有了新的认识．通过优化测量参数，选取３６０℃测量，剔除低温峰，减缓了照射后衰退速率，提高了剂量测量的准确度，使手表红宝石作为辐射事故剂量计使用更为可靠．     

宫颈癌腔内放射治疗的三维剂量分布验证

目的:采用成都仿真人体盆腔模型及LIF(Mg.Cu.P)热释光剂量计(TLD)验证宫颈癌腔内后装治疗三维剂量分布的可行性. 方法:根据临床腔内后装放射治疗模拟计划方案,在仿真人体盆腔模型内设置参考点(孔),把TLD元件放入仿真人体盆腔模型测试孔内,用MicroSelectron HDR后装治疗机按模拟计划设计进行腔内照射, FJ427-A1热释光剂量仪对受照后TLD元件进行重复测量,比较计算值和测量值的差异. 结果:本次采用的TLD元件剂量线性好,A, B, F点、膀胱和直肠剂量参考点实测剂量与3DV-TPS计算值符合较好,其平均误差在±5.16%. 结论:TLD实测剂量能较好的反应患者的实际受照剂量,对预测放疗副作用、优化放疗计划、提高疗效有重要价值.     

放射性^125I粒子植入术后患者及密切接触者的剂量监测

目的：分析^125I粒子植入术后对患者、患者周边及密切接触者的受照剂量率并估算年剂量,及在该剂量率的条件下达到剂量限值所需要的时间。方法：采用热释光剂量计检测20例^125I植入后的患者体表、病人家属、病人床边、邻床床边及医护人员的受照剂量率,并根据公式推算这些检测点受到照射的年剂量,及在该剂量率的条件下达到剂量限值时所需要的时间。结果：患者体表平均剂量率为214．54μGy／h,其中头颈部肿瘤、腹部肿瘤、前列腺癌及其他肿瘤患者体表的平均剂量率分别为4193．18μLGy／h,22．97μGy／h,160．34μGy／h,9656．32μGy／h,年当量剂量平均值为441．25mSv,其中头颈部肿瘤、腹部肿瘤、前列腺癌及其他肿瘤患者体表的年当量剂量分别为8624．14mSv,47．24mSv,329．77mSv,19860．21mSv。累计剂量达到5mSv和1mSv所需要的平均时间分别为：23．44h和4．67h,其中头颈部肿瘤、腹部肿瘤、前列腺癌及其他肿瘤患者累计剂量达到5mSv和lmSv所需要的平均时间分别为：1．19h和0．24h、230．07h和44．00h、31．42h和6．25h、0．52h和0．10h。与患者密切接触者及位于其周边位点的年当量剂量均值最大为0．01mSv。结论：^125I粒子组织间近距离治疗术后病人,其周边环境及其密切接触者是安全的。