荧光玻璃、热释光和光释光探测器性能比较

介绍了荧光玻璃探测器、热释光探测器和光释光探测器基本原理和近期发展,并总结了荧光玻璃、热释光探测器、光释光探测器的优缺点.荧光玻璃最大优点是长期稳定性好和可多次读取.热释光和光释光探测器具有灵敏度高、低探测阈、较好的稳定性和能量响应、环境适应性强等优点.但与LiF:Mg,Cu,P相比,α- Al2O3:C光释光探测器对...     

释光断代技术研究

本文对释光断代中遇到的问题提出了一些看法,供同行们进一步研究和讨论.     

释光探源

释光技术用于年龄测定的依据是磷光体能够储存辐射的能量,但磷光体对不同辐射种类的能量吸收效率和释光响应各不相同,因此释光测定年龄这一技术本身要求各种学科知识的支撑,有些知识甚至是本学科都尚未深入研究的。作者简述了释光测年技术的历史,并以自身的实践阐述在对释光的认识过程中所必须具备的知识。还以长石为例,叙述了在自行开发的BG2003释光谱仪上新进行的研究工作。     

黄土细颗粒单测片再生法光释光测年的进展

报道了黄土细颗粒石英与混合矿物单测片再生法测年中的若干进展。在黄土细颗粒释光测年前处理方面，利用氟硅酸溶蚀法提取可供释光测年的细颗粒石英，突出溶蚀过程需用超声波克服细颗粒矿物表面能的重要性；在此基础上，利用单测片再生法测定洛川黄土细颗粒石英光释光等效剂量，作为标准评估混合矿物红外-蓝光联合激发单测片再生测定等效剂量的可靠性。通过线性激发技术证实了长时间红外激发后蓝光释光信号和细颗粒石英光释光信号中快速和中速信号组份之间存在着相似的特征，提出红外后蓝光释光测年需进行红外激发时间与红外后蓝光释光等效剂量坪实验，以获得蓝光激发前红外激发参数。通过与细颗粒石英等效剂量的对比，系统地研究了细颗粒混合矿物单测片再生法确定的红外与红外后蓝光释光等效剂量的可靠性。     

黄土细颗粒混合矿物红外释光和红外后蓝光释光的环境意义

本研究目的在于揭示黄土细颗粒混合矿物红外释光(IRSL)和红外后蓝光释光([post-IR]OSL)再生剂量信号强度与环境变化之间的可能联系.在相同的测试条件下,洛川末次间冰期以来黄土-古土壤序列细颗粒混合矿物的再生剂量感量变化校正后红外释光(IRSL)和红外后蓝光释光([post-IR]OSL)信号强度随地层的变化及其与磁化率的良好对应关系,显示了这两种释光信号强度与环境变化的可能联系;另外,黄土高原自西北(NW)-东南(SE)方向四个剖面马兰黄土(L1)上部样品再生剂量IRSL,和[post-IR]OSL信号强度趋于逐渐增强表明,两个释光信号强度随气候由冷干向暖湿过渡而呈现逐渐增大的趋势,进一步证实了它们与环境变化之间的联系.IRSL信号强度的变化可能与混合矿物中长石种类或含量有关,而[post-IR]OSL强度变化可能受控于长石矿物对该信号的贡献量.两个信号可以间接反映环境变化的信息.实验结果同时也表明应当慎重使用细颗粒混合矿物[post-IR]OSL信号测年.     

掺碳氧化铝复合光释光探测器制备及性能测试

针对单晶片状掺碳氧化铝光释光探测器灵敏度差异性大的问题,研究了不同粒径掺碳氧化铝粉体的光释光灵敏度,采用光学类环氧树脂和掺碳氧化铝粉末制备了两种复合掺碳氧化铝光释光探测器,并测试了其光释光剂量响应、最小可测剂量和重复性能。结果表明,在粉体粒径为200～300μm时,具有最高的光释光灵敏度;复合光释光探测器剂量响应呈线性-超线性的特点,剂量10 Gy以下呈良好的线性,最小可测剂量低至33.7μGy;复合光释光探测器响应具有良好的重复使用特性,变异系数小于1.5%。验证了复合光释光探测器的技术可行性,为掺碳氧化铝晶体的应用提供了一条新的路径。     

油气勘察样品的多波段激发光释光曲线特征

在热释光研究和应用的基础上,重点探讨了光释光方法在油田勘察中应用的可行性.实验采用的激发波段分别为514 nm、600nm、685nm、740nm和800nm,数据采集时间分别为5s、10s、15s、20s、25s、30s和35s.结果表明,同一个样品,经过不同能量的激光激活,可以得到数个不同水平的光子响应.由此证明,光释光发光曲线与热释光发光曲线都是不同能级陷阱中的电子跃迁表现.     

SrSO4:EU和CaSO4:EU的热释光和光释光发光谱

测量了SrSO4：Eu(摩尔分数为0．1％)和CaSO4：Eu(摩尔分数为0．1％)的光释光发光谱和热释光发光谱,得到SrSO4：Eu的光释光发光波长与热释光发光波长均为375nm,而CaSO4：Eu的光释光发光波长与热释光发光波长均为385nm,说明热释光和光释光具有相同的发光中心,均来自于Eu^2 的能级跃迁。同时在CaSO4：Eu的热释光发光谱中还观察到了Eu^3 的发光。     

水成沉积物释光测年研究进展与展望

石英光释光(OSL)测年方法对于蕴藏着丰富区域气候环境变迁、古洪水、古地震及构造信息的冲积、洪积、湖积等水成沉积物组成的沉积地层,面临许多难题.水成沉积物矿物颗粒在搬运和沉积过程中,先前积存的释光信号能否被晒退,晒退是否均匀?残留水平如何?如何准确测定这些沉积物的天然释光信号强度的等效剂量(De)?环境剂量率怎样才能准确测定等问题,是几十年来国内外释光测年研究者普遍关注的问题.本文通过对水成沉积物研究成果的梳理、存在问题及研究现状分析,探讨了光释光测年方法在水成沉积物方面的应用前景.     

湖光岩砂石的释光剂量研究

采集湖光岩玛尔湖周围部分岩洞内的岩样及岩壁下和湖岸边的砂土样品,用粗颗粒法测量它们的热释光和光释光;用复合作用剂量响应模型分析热释光和光释光剂量响应,并计算对应的热释光和光释光古剂量。结果表明:相同采样点的样品,热释光和光释光古剂量间都存在一些差异;不同采样点样品的释光剂量相差很大;热释光古剂量测量值较准确的样品,光释光古剂量测量值与热释光测量值无显著的数量级差别。此测量分析对第四纪火山考古有一定参考意义。     

结晶固体的辐射损伤与释光

从辐射与物质的作用出发,对释光现象进行了讨论,认识到结晶固体的释光效应最本质的是结晶固体中的杂质离子。它们在固体中形成的发光中心有两类,一类是辐射本质,它对辐射的释光响应正比于它所接受的辐射剂量;另一类属于非辐射本质的,全由固体中的杂质离子所决定。     

Radiation-induced luminescence of PET and PEN films under MeV ion and pulsed UV laser irradiation

Ion- and photo-induced luminescence of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) films was investigated during irradiation by MeV H and He ions and an ultraviolet pulsed laser. At the beginning of ion irradiation, the PEN film emitted blue luminescence, whose intensity was an order of magnitude higher than that emitted by the PET film. Successive ion irradiation effectively reduced the luminescence centers, and the rate of decease in luminescence intensity depended on the energy deposited along the trajectory of the ions. Optical absorption measurements in the infrared region revealed an irradiation-sensitive feature of the PEN film. Moreover, a photo-induced band grew remarkably at 470 nm in the PET film under 266 nm pulsed laser irradiation, while the PEN film showed a moderate decrease in luminescence intensity at 440 nm.     

Reaction kinetics of radiation-induced defects in vitreous silica under ion beam irradiation

The production behavior of radiation-induced defects in vitreous silica was studied by an in-situ luminescence measurement technique under ion beam irradiation of He⁺. The luminescence intensity of oxygen deficiency centers (ODCs) at 460 nm was observed to vary with irradiation time reflecting the accumulation behavior of the ODCs. The luminescence intensity increased after the start of irradiation and then decreased at room temperature, while it increased rapidly to a constant value at higher temperatures. Some differences were observed due to different OH contents in silica. The observations were analyzed by considering the production mechanisms and kinetics of the radiation-induced defects.     

Temperature dependence of luminescence from a silica glass under in-reactor irradiation

We have investigated in-reactor luminescence (IRL) from a silica glass at temperatures ranging from 100 K to 250 K. The IRL consists mainly of a broad emission band peaked at 2.7 eV assigned to oxygen deficient centers produced in the silica glass under the in-reactor irradiation. The 2.7 eV emission intensity linearly increased with the irradiation time and its increasing rate was larger for higher irradiation temperatures. However, this temperature dependence is inconsistent with that for the defect production rate and the cause is not clear at present. The initial intensity of the 2.7 eV IRL band increases with temperature, showing an activation energy of ca 21 meV. This value is much lower than those observed in the temperature dependence of the 2.7 eV photoluminescence (PL) and the cathodeluminescence (CL) induced by 8 keV electron irradiation. These results suggest that in IRL, some electrons excited to higher energy levels than the luminescence level are likely transferred to the luminescence state without thermal activation, resulting in a lower activation energy in their temperature dependence.     

Production behavior of irradiation defects in vitreous silica under ion beam irradiation

The production behavior of irradiation defects in vitreous silica was studied by an in situ luminescence measurement technique under ion beam irradiation of H⁺ and He⁺. No apparent difference was observed in the luminescence spectra of specimens of different OH contents. The temperature dependence of the luminescence intensity at 280 and 460 nm was measured, and analyzed by considering the production mechanisms and kinetics of the irradiation defects of oxygen deficiency centers.     

The role of radiolysis products in in situ luminescence of Li2O

A new phenomenon of an “excess luminescence” (EL) in Li₂O observed at 4.5–2.5 eV under light ion (H⁺, He⁺) irradiation during the rise of temperature (>573 K) was studied. The essence of the EL is in the rapid pulse increase of the luminescence intensity. It is proposed that this phenomenon is based on the thermo-dissociation of colloidal Li into Li lattice ions, F⁺ and F⁰ centers, and oxygen vacancies. Formed oxygen vacancies capture electrons during the irradiation and form excited F-centers, whose relaxation gives the EL. This phenomenon was reproduced using X-ray irradiation and a sample containing colloidal Li introduced by irradiation with electron accelerator to an absorbed dose of 105 MGy.     

超微弱发光分析法在辐照糖类食品中鉴别检测的应用

糖是大多数食品的重要组成部分。本工作应用超微弱发光分析技术,研究三种糖分在辐照前后变化过程,以建立一种无需对照样品的辐照食品鉴别检测新方法。研究结果表明,食品经不同剂量^60Coγ射线辐照处理后,在干燥状态下,辐照后葡萄糖和蔗糖样品的超微弱发光强度变化不大。但是,在测量过程中瞬间加水溶液后,样品的超微弱发光强度会产生显著变化,其发光峰所对应的光子数与辐照剂量密切相关。根据这一特有的变化规律,     

Optically stimulated luminescence dosimeter based on CaS：Eu,Sm

Alkaline earth sulfides (MgS, CaS and BaS) crystal doped with rare-earth ions is an optically stimulated luminescence dosimeter with very high sensitivity, short time constant of the optically stimulated luminescence (OSL)separated perfectly from the stimulation. In this paper, an OSL dosimeter is described. It has linear dose response from 0.01 to 1000 Gy. The equipment, relatively simple and small in size is promising for applications in space exploration and for high dose irradiation and dangerous irradiation conditions.     

正电子辐照多孔硅的研究

多孔硅经来自＾２３Ｎａ的正电子束辐照后，其光荧光谱出现两个新特点，一是主峰峰位显著蓝移，由辐照臆的红色光谱区蓝移到辐照后的绿以光谱区；二是出现一个较高能量的附加发光峰，红外吸收谱表明，正电子辐照有助于增强多孔硅的表面氧化对多孔硅经正电子辐照后光荧光结构改变的机理进行了讨论。     

Effect of 80-MeV nitrogen ion irradiation on ZnO nanoparticles: Mechanism of selective defect related radiative emission features

We report on the 80-MeV nitrogen ion irradiation on spherical ZnO nanoparticles fabricated by way of solid state mixing. The structural and compositional analyses of the as-synthesized ZnO nanoparticles were done by X-ray diffraction, electron microscopy and energy dispersive spectroscopy studies. As evident from the optical absorption spectra, the energetic ion irradiation, on the nanoparticle system, is governed by evolution of new characteristic absorption features owing to modification in the electronic states. Again, in the luminescence spectra, though the near band-edge emission was not observable for pristine ZnO, it was recovered (at ∼385 nm) upon irradiation. As far as the defect related emission is concerned, a competition between the formation and annihilation of different defects (especially, zinc vacancies and interstitials) at different ion fluences was realized. Correlating the luminescence spectra and the theoretical investigation, it can be understood that during irradiation the formation of zinc related defects are energetically favorable than the oxygen related counterparts. Exploration of defect related radiative features corresponding to definite structural organization/modification would help in making next generation light emitting and display devices, where a select emission response is desired.