掺Dy的MgB4O7磷光体的研制及其热释光特性

以碳酸镁和硼酸为原料在高温条件下合成了基质材料MgB4O7并制备了MgB4O7∶Dy磷光体.用RGD-3热释光剂量仪和三维热释光谱仪分别测量了这种磷光体的二维发光曲线和三维发光谱,实验观察到:1)MgB4O7∶Dy磷光体热释光发光峰峰温为220 ℃和380 ℃;2)Dy3 离子的发光波长为480 nm、575 nm和660 nm;3)磷光体220 ℃和380 ℃发光峰的相对强度随高温固相反应温度的升高而变化,但发光峰温和波长基本保持不变.对比MgB4O7∶Dy和MgSO4∶Dy两种热释光材料的三维发光谱,验证了掺入Dy3 离子的热释光材料的发光峰峰温主要由基质材料决定,发光波长则取决于Dy3 离子的能级跃迁的结果.     

掺入Dy和Mn的MgSO4磷光体的热释光发光光谱

用光学多道分析器和微机控制线性升温法研究了MgSO4:Dy和MgSO4:Dy,Mn热释光材料的发光光谱,测定不同温度和波长的发光光谱,得到了热释光三维光谱图。观察到MgSO4掺入稀土元素Dy的两个发光谱带为480nm和580nm,每个光谱带有多个发光峰。与掺入Dy的CaSO4的三维发光谱相比较,掺入稀土元素Dy的热释光材料的发光谱带的波长主要取决于掺入Dy^3 的能级间的跃迁。MgSO4同时掺入Dy和Mn后,480nm发光谱带受到很大的抑制,所有发光峰的发光效应显著减小;波长为580nm谱带的多个发光峰中,温度低于300℃的发光峰的发光效率显著减小,在380℃附近的发光峰的发光强度最大。这说明掺入Mn杂质后,不同深度的陷阱的相对分布发生了变化。     

掺入Dy和Mn的MgSO_4磷光体的热释光发光光谱

用光学多道分析器和微机控制线性升温法研究了MgSO4 :Dy和MgSO4 :Dy ,Mn热释光材料的发光光谱。测定不同温度和波长的发光光谱 ,得到了热释光三维光谱图。观察到MgSO4 掺入稀土元素Dy的两个发光谱带为 4 80nm和 580nm ,每个光谱带有多个发光峰。与掺入Dy的Ca SO4 的三维发光谱相比较 ,掺入稀土元素Dy的热释光材料的发光谱带的波长主要取决于掺入Dy3+的能级间的跃迁。MgSO4 同时掺入Dy和Mn后 ,4 80nm发光谱带受到很大的抑制 ,所有发光峰的发光效率显著减小 ;波长为 580nm谱带的多个发光峰中 ,温度低于 30 0℃的发光峰的发光效率显著减小 ,在 380℃附近的发光峰的发光强度最大。这说明掺入Mn杂质后 ,不同深度的陷阱的相对分布发生了变化。     

MgB4O7:Tm,Mn磷光体的热释光特性

采用高温固相法制备了MgB4O7:Tm,Mn磷光体材料,测量了热释光发光曲线和热释光三维光谱以及剂量响应曲线。其主发光峰温度约为400oC,发光波长455 nm。MgB4O7:Tm,Mn主发光峰面积比LiF:Mg,Ti高6.2倍,具有很好的热稳定性,在0.1–2000 Gy范围内具有良好的线性-超线性剂量响应。     

MgB4O7:Tb磷光体的研制及其热释光(TL)特性

以碳酸镁和硼酸为原料在高温条件下合成了基质材料MgB4O7并制备了MgB4O7：Tb磷光体。用Risφ／OSL-15-B／C热释光（TL）,光释光（OSL）自动测量仪和TL/OSL三维光谱自动测量仪分别测量了这种磷光体的二维热释光发光曲线和三维热释光发光谱。由MgB4O7：Tb的三维热释光发光谱可看出这种磷光体在230℃、340℃和420℃附近有三个热释光峰,发光谱的波长分别为489nm、548nm、589nm和620nm。此外,不同的高温烧结温度不仅对发光峰的发光强度有很大影响,而且还对。Tb^3＋发光谱形产生影响。当温度高于850℃时Tb^3＋离子发光谱线开始变成了发光谱带。     

掺Dy,Tm和Mn的MgSO4磷光体的热释光发光谱研究

用高温固相法研制了MgSO₄:Dy,MgSO₄:Tm和MgSO₄:Mn热释光材料,并通过将MgSO₄:Dy和MgSO₄:Mn混合,以及MgSO₄:Tm和MgSO₄:Mn混合烧结得到了双掺杂样品MgSO₄:Dy,Mn,MgSO₄:Tm,Mn。分别测量了这两种样品在不同热处理温度下的三维发光谱。实验结果表明热处理温度为700℃时的样品,在测量加热过程中观察到Dy和Mn离子分别发光,但超过800℃后,Mn发光强度逐渐变弱,而Tm、Dy的高温发光峰逐渐变强,其它温度的发光峰受到抑制。这表明热释光材料中形成的缺陷复合体结构与热处理温度相关,随着热处理温度的升高,愈来愈多的Mn离子与稀土离子结合紧密,因此在热释光发光谱中清楚地观察到Mn离子对稀土离子的能量转移和对Tm、Dy低于400℃发光峰进行抑制的发光过程。     

SrSO4:Eu磷光体的热释光特性

研究了掺杂得到的SrSO4Eu(0.1mol%)的粉末样品的热释光(TL)发光曲线和三维光谱.用90Sr的β射线辐照0.116～1.16 kGy后.测到的热释光峰发光曲线,观察到只有一个主剂量峰,峰温位于(231.5±2.3)C.用热释光一般级动力学方程拟合发光曲线,得到了峰参数和陷阱参数值.主剂量峰基本上不随照射剂量发生变化,辐射剂量响应为线性-亚线性.用+0℃oγ辐照100Gy后.测量了热释光三维光谱,确定了发光波长主要位于375nm.与其他硫酸盐基质材料中掺Eu的CaSO4Eu.MgSO4Eu比较.波长有所不同.可以确定这是来自于Eu2+能级跃迁的发光.     

MgSO4:Tm,Mn,P磷光体的研究

通过三掺杂得到MgSO4：Tm,Mn,P，其热释光的两个主要发光峰温分别约为253℃和383℃，发光波长位于365nm、460nm和660nm。比较MgSO4:Tm、MgSO4:Tm,Mn、MgSO4:Tm,P、MgSO4：Tm,Mn,P的发光曲线，讨论了杂质Tm、Mn、P分别产生的作用。采用一般级动力学方程拟合发光曲线，确定出各发光峰的激活能与频率因子。用^60Co γ射线在0.1-20kGy的辐照范围内，测定了它们的热释光剂量响应曲线。用复合作用剂量响应函数拟合实验数据，得到两个发光峰的一次作用因子R分别为0.397(253℃）和0.127(383℃）。     

MgSO_4:Dy,P和MgSO_4:Dy,P,Cu的热释光剂量学特性

MgSO4 :Dy中掺入适量的P ,热释光发光曲线中两个高温峰显著增强 ,主剂量峰的峰温接近2 83.6℃ ,另一个发光峰的峰温在 35 2 .7℃ ,其热释光效率超过LiF:Mg ,Ti的两倍。MgSO4 :Dy ,P的单个发光峰峰面积对60 Coγ辐射剂量 (0 .1Gy— 2 0kGy)的实验响应曲线用复合作用响应函数拟合 ,得到的非线性特征参数表明 ,两个发光峰的γ辐射剂量响应均为超线性。在MgSO4 :Dy ,P中再掺入微量Cu ,首先抑制峰温在 35 2 .7℃的发光峰 ,随着Cu浓度的增加 ,2 83.6℃的主剂量峰会随之降低 ,此峰的γ辐射剂量响应的超线性随之减小。MgSO4 :Dy ,P ,Cu (0 .1mol% ,0 .5mol% ,0 .0 1mol% )磷光体对γ辐射的剂量响应 (0 .1Gy— 2 0kGy)为亚线性。最引人注目的是MgSO4 :Dy ,P ,Cu(0 .1mol% ,0 .5mol% ,0 .0 0 4mol% )磷光体 ,它具有与MgSO4 :Dy ,P(0 .1mol% ,0 .5mol% )相近的热释光灵敏度 ,并具有最宽的剂量响应线性范围。这种新热释光材料可用于高剂量辐射测量。本文进一步阐明和验证了《复合作用模型》 ,并揭示了热释光材料中杂质和缺陷结构与剂量学特性的相关性。结合热释光三维发光光谱的分析对热释光机制提出一些见解     

MgSO4：Dy,P和MgSO4：Dy,P,Cu的热释光剂量学特性

MgSO4:Dy中掺入适量的P,热释发光光曲线中两个高温峰显著增强,主剂量峰的峰温接近283．6℃,另一个发光峰的峰温在352．7℃,其热释光效率超过LiF:Mg,Ti的两倍,MgSO4:Dy,P的单个发光峰峰面积对^60Coγ辐射剂量（0．1Gy-20kGy)的实验响应曲线用复合作用响应函数拟合,得到的非线性特征参数表明,两个发光峰的γ辐射量响应均为超线性,在MgSO4:Dy,P中再掺入微量Cu,首先抑制峰温在352．7℃的发光峰,随着Cu浓度的增加,283．6℃的主剂量峰会随之降低,此的γ辐射剂量响应的超线性随之减小,MgSO4:Dy,P,Cu(0.1mol%,0.5mol%,0.01mol%)磷光体对γ辐射的剂理响应（0．1Gy-20kGy)为亚线性,最引人注目的是MgSO4:Dy,P,Cu(0.1mol%,0.5mol%,0.004%mol)磷光体,它具有与MgSO4:Dy,P(0.1mol%,0.5mol%)相近的热释光灵敏度,并具有最宽的剂量响应线性范围,这种新热释光材料可用于高剂量辐射测量。本文进一步阐明和验证了《复合作用模型》,并揭示了热释光材料中杂质和缺隐结构与剂量学特性的相关性,结合热释光三维发光光谱的分析对热释光机制提出一些见解。     

Study of the luminescent properties of KMgF3:Sm

The photoluminescence (PL), radioluminescence (RL) and thermoluminescence (TL) of KMgF₃ doped at several Sm concentrations have been investigated. The maximum TL and RL yield under beta irradiation has been observed in KMgF₃:Sm 0.02 mol%. The glow curve of this doped perovskite is made up of at least five peaks located at 95, 120, 160, 270, and 330 °C. The third peak appears to be the most convenient for personal or environmental dosimetry, since it shows no fading and good linearity within the investigated dose range (0.020-200 Gy). From the RL and PL spectra it has been found that most of KMgF₃:Sm emission is located at wavelengths higher than 650 nm. This emission, which is characteristic of Sm²⁺, makes this doped compound attractive for fiber-optic dosimetry.     

沙漠砂的选频释光特征

采用BG2003释光仪研究新疆的克拉玛依、沙湾黄梁、阜康西和鄯善，甘肃的雅丹、月牙泉，河北的天漠8个沙漠砂样品的选频释光特征，确定了发射光子的特征发射频率。在红光（632.8nm）激发下，释光光子波长为480和320nm时最为突显；热释光峰（350～400℃）释放出最多光子的波长分别为460和350nm。沙湾黄梁、鄯善、天漠冲积扇在波长为500nm和鄯善在波长310nm时表现出在一定剂量范围内释光光子数随辐照剂量增大的趋势，所以，此波长可分别用于测年。     

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。     

Properties of CaSO4(Mn) Powder for Thermoluminescence Dosimeter

Thermoluminescence and electron paramagnetic resonance (EPR) of CaSO₄(Mn) powder have been studied. The intensities of the hyperfine lines in the EPR spectra of Mn⁺⁺ and the heights of the thermoluminescence glow peak are found to change in parallel, upon varying the conditions of heat treatment and the concentration of Mn⁺⁺. It is also found that Mn⁺⁺ present in aggregate state, which gives a broad EPR spectrum, is not an effective activator for thermoluminescence; heat treatment at high temperatures serves to disperse this aggregated Mn⁺⁺, which increases the thermoluminescence sensitivity. The relation between the thermoluminescence intensity and the radiation dose is linear, so long as the duration of irradiation is within certain limits; the deviation from the linear relation is explained in terms of fading of thermoluminescence at the temperature of irradiation.     

热加工对Zr-Sn-Nb锆合金显微组织和耐腐蚀性能的影响

将Zr-Sn-Nb新锆合金样品分别进行多种变形热处理，用透射电子显微镜研究它们的显微组织和第二相粒子。然后，将它们放入高压釜中，在350℃、16.8MPa、含70μg/gLi⁺的LiOH水溶液中腐蚀。结果表明：580℃ 3h/冷轧/500℃ 30h处理的样品具有最好的耐腐蚀性能，这归因于该样品中Zr-Nb-Fe第二相粒子细小分布均匀、第二相粒子体积分数最高，从而导致基体中的Nb元素固溶含量最低。     

Dosimetric properties of UV irradiated calcium co-doped borate glass-ceramic

The thermoluminescence (TL) response of Dy and Li doped 20CaB₄O₇-80CaB₂O₄ (wt%) glass-ceramic irradiated with ultraviolet (UV) radiation was studied. In order to act as TL activator ions, the Dy and Li ions were included in the matrix during the melting process to increase its TL efficiency. A single crystalline CaB₂O₄ phase was present in the glass-ceramic as determined by X-ray diffraction (XRD). The glass-ceramic 20CaB₄O₇-80CaB₂O₄:Dy,Li wt% (named 20CBO7:Dy,Li) is a newly prepared TL material. Its thermoluminescent dosimetric characteristics have shown a linear response under UV radiation exposure and a good TL signal reproducibility, thus proving to be a promising material for using as an ultraviolet radiation dosimeter.     

X-ray absorption spectroscopy and X-ray photoelectron spectroscopy studies of CaSO4:Dy thermoluminescent phosphors

Extended X-ray absorption fine structure (EXAFS) measurements have been carried out on CaSO₄:Dy phosphor samples at the Dy L₃ edge with synchrotron radiation. Measurements were carried out on a set of samples which were subjected to post-preparation annealing at different temperatures and for different cycles. The EXAFS data have been analysed to find the Dy-S and Dy-O bond lengths in the neighbourhood of the Dy atoms in a CaSO₄ matrix. The observations from EXAFS measurements were verified with XANES and XPS techniques. On the basis of these measurements, efforts were made to explain the loss of thermoluminescence sensitivity of CaSO₄:Dy phosphors after repeated cycles of annealing at 400 °C in air for 1 h.     

Calcium Sulfate Activated by Lead and Manganese for Thermoluminescence Dosimetry

CaSO₄: Pb, Mn has been found to be free from the serious disadvantage of rapid fading possessed by CaSO₄: Mn, the most sensitive thermoluminescence phosphor available so far. A study has been made on the effect of lead and manganese content on CaSO₄, and it is concluded that lead in CaSO₄ produces new traps for radiation energy, resulting in improvement of the properties of the phosphors for dosimetry. The optimum content of such activator additives was found to be 0.2 mol/₀ of lead and 3 mol/₀ of manganese.

The improved phosphor thus obtained produces glow peaks at 160° and 190°C, and the energy yield of the thermoluminescence is about which is twice that of CaSO₄: Mn. The more significant properties of this phosphor from the viewpoint of application to radiation dosimetry include:

(1) Linear responce from 50μR to 10⁴R

(2) Minimum detectable dose of 50μR±25% by experimental reader

(3) Fading rate of 5% in a week