共查询到20条相似文献,搜索用时 15 毫秒
1.
冰洲石120℃热释光峰特性 总被引:1,自引:0,他引:1
对冰洲石120℃热释光峰的基本特性进行初步研究。实验结果表明,在30℃下,冰洲石120℃热释光峰的寿命约为2h。在实验升温速率增大情况下,该峰值将向高温区移动。在15Gy的辐射剂量范围内,冰洲石120℃热释光峰的强度与辐射剂量呈正比。 相似文献
2.
The growth of thermoluminescence (TL) and optical absorption (OA) with absorbed dose was examined in LiF doped with Mg, as functions of both the linear energy transfer (LET) of the incident radiation and the impurity content of the samples. In addition, the TL growth curves were examined as a function of the heating rate during readout. The growth of TL as a function of dose is basically linear-supralinear-sublinear, but the precise character of the dose response function varies with the LET of irradiation, the Mg impurity content of the sample, and the heating rate during TL readout. the OA dose response is always linear-sublinear over the same dose ranges, even for those defect centers that are known to be involved in the TL process. The data indicate that the mechanisms responsible for the supralinear nature of the TL growth are operative during the TL readout phase rather than the absorption phase. A mathematical model is presented that qualitatively describes the results. The model is conceptually the same as the so-called track interaction model for high-LET irradiation, but the extension presented here makes it applicable to gamma-irradiated samples also 相似文献
3.
报道了铀矿脉中石英热释光强度随放射性元素含量增加而降低的异常现象。从高能辐射作用于物体时的两种效应入手,分析讨论了异致热释光强度降低的原因。石英热释光的发光曲线特征揭示了铀矿脉形成的热历史。根据铀、钍、钾含量,计算了铀矿脉中岩矿石的放射生热率,并讨论了石英热释光强度与放射生热率的关系。 相似文献
4.
5.
目的探讨利用热释光剂量计对工业脉冲X射线发生装置进行放射防护检测与评价的可行性。方法分别用热释光剂量计和AT1123型X/γ辐射剂量率仪测量脉冲X射线发生装置的辐射剂量,通过对测量结果的分析和比较验证热释光剂量计测量脉冲X射线的有效性,通过对周围环境中年累积剂量的估算来评价试验人员和公众的受照剂量是否满足辐射防护要求。结果1号脉冲X射线发生装置曝光4次,2号脉冲X射线发生装置曝光10次,热释光法测得不同距离处的累积剂量符合距离平方反比衰减规律,实际检测结果与理论推算值较为吻合。两个X射线发生装置现有的工作负荷下,工作人员和公众的年累积剂量均在辐射防护控制目标值内。结论热释光法得出检测结果与理论推算值较为吻合,能够满足工业脉冲X射线发生装置放射防护检测需求。 相似文献
6.
7.
C. Soliman E. Salama 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(19):3323-3327
The suitability of sandstone for the gamma radiation dosimetry using thermoluminescence technique is investigated. Its properties are systematically studied utilizing atomic absorption spectrometry, measurements of natural and laboratory-induced blue thermoluminescence emission band, trap depths and storage effects. The emission of the natural blue-band exhibited broad peak at ∼315 °C. The thermoluminescence gamma dose response has a linear behavior over the dose range 1-50 Gy followed by sub-linearity at high dose level, with standard deviation in all cases less than ±9%. Trapping depths showed a closely spaced set of traps for both the natural and laboratory-induced glow curves. The variation in thermoluminescence signal over 1 week storage period at room temperature was not more than 7%. The thermoluminescence fading effects were explained by the localized transition model. From our results, it is possible to conclude that natural sandstone is a suitable material for accident and industrial dosimetric applications. 相似文献
8.
Mustafa Topaksu 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2007,264(2):293-301
In this study, the thermoluminescence (TL) properties of natural CaF2 were investigated after β-irradiation at room temperature (RT). The additive dose (AD), Tm(Ea)-Tstop, repeated initial rise (RIR), and computerized glow curve deconvolution (CGCD) methods were used to analyze the thermoluminescence (TL) glow peaks in natural CaF2 after β-irradiation between 0.015 Gy and ≈2 kGy dose level. These methods were used to determine the number of peaks and kinetic parameters (kinetic orders b, activation energy Ea, and attempt-to-escape frequency s) associated with the thermoluminescence (TL) glow peaks of natural CaF2. The Ea-Tstop and CGCD methods indicate that the glow curve of this material is the superposition of at least six glow peaks, which were dealt with as P1-P6, in the temperature range between room temperature (RT) and 400 °C. Dose variation experiments revealed that TL glow curve of natural CaF2 has both first and general-order glow peaks. The dose responses and fading process, which are very useful in radiation dosimetry, of individual TL peaks of this material were also examined. In addition, the influence of heating rates on the response of dosimetric glow peaks of natural CaF2 was studied. It was observed that the total area of glow peak and peak intensities of all glow peaks are continuously decreasing with increasing heating rate. 相似文献
9.
国产氟化锂片型热释光探测器性能比较研究 总被引:5,自引:0,他引:5
本文报道了对常用国产LiF(Mg,Cu,P)和LiF(Mg,Ti)两类片型热释光探测器的6种产品进行剂量学性能比较研究的结果。根据国家标准“个人和环境监测用热释光剂量测量系统”的技术要求和实际需求,比较了这几种探测器的热释发光曲线,相对灵敏度,探测阈,线性度,光子能量响应,一批的均匀性,重复性和稳定性等剂量学特性。文中还对TL探测器应用中的有关问题作了讨论。 相似文献
10.
EFFECTOFTHERATIOTh/UONTLDATINGACCURACY¥P.L.Leung(梁宝鎏);MichaelJ.Stokes(DepartmentofPhysicsandMaterialsScience,CityPolytechnico... 相似文献
11.
12.
鉴别式热释光个人剂量计的性能及参加国际比对的概况 总被引:4,自引:0,他引:4
介绍了鉴别式热释光个人剂量计的性能。包括剂量计结构,实验方法,体模反散射,能量响应和角响应以及能量鉴别和剂量刻度。用此剂量计参加了由IAEA/RCA组织的个人剂量监测国际比对,在两个比对阶段中均获得了满意的结果。到目前为止,国内已有近50个个人剂量监测单位拥有该剂量计。 相似文献
13.
14.
《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2004,217(4):611-620
The thermostimulated luminescence (TSL) glow curve characteristics of 10 blue coloured calcite crystals of Southern Tamilnadu are analysed. The natural thermoluminescence (NTL) measurements were carried out for all the samples and annealed in air at the temperatures ranging from 200 to 700 °C, at an interval of 50 °C, for 1 h duration. The glow curves of annealed and unannealed samples irradiated with a gamma dose of 500 Gy show three peaks at 145, 255 and 345 °C, respectively, when recorded with a linear heating rate of 10 °C/s. Annealing treatment above 400 °C increases the sensitivity of all TSL peaks except 345 °C. On the other hand, annealing at 700 °C caused a collapse in the TSL sensitivity. The enhancement in TSL sensitivity was found to depend on the annealing temperature and time. Annealing treatment at 600 °C for 5 h followed by quenching in air is the optimum conditions for TSL sensitization. The response to gamma irradiation is linear in the range from 1 to 104 Gy. The emission spectra of all the samples show an emission at around 610 nm but with different intensities for each sample. With reference to earlier work, it may be assumed that the recombination site always involves Mn2+ ions. 相似文献
15.
应用热释光技术对模拟阳光晒退后的泥石流标样和实际阳光晒退后的泥石流样品进行了热释光信号分层测定。实验结果表明:泥石流发生后经过曝光,样品积存热释光晒退程度随深度增加逐渐减弱,光晒退明显。光晒退随光照强度和时间增大而增强,深度增大,但深度变化总体不大。模拟的阳光晒退实验晒退深度达1 mm左右,实际阳光晒退实验晒退深度达6 mm左右。根据等效剂量随深度的变化可知,天然泥石流块状样由两次泥石流堆积形成。这一结果可为利用热释光技术开展泥石流测年和发生期次研究提供依据。 相似文献
16.
对离体培养的人血淋巴细胞和昆明种小白鼠预先给予小剂量X射线照射(50mGy),然后给予不同剂量及不同剂量率的大剂量照射(0.75-3.75Gy),观察适应性反应的程度。结果表明,在0.75-3.0Gy剂量范围内,可出现适应性反应;剂量大于3.0Gy时适应性反应消失;当剂量一定(1.5Gy)时,适应性反应的程度和剂量率呈负相关。 相似文献
17.
本文报道了电子静电加速器产生的两种能量的电子射线(0.8 MeV和0.5 MeV)在小麦辐射 育种中应用的初步结果。试验表明:电子射线对小麦萌发种子的辐照后,其辐照当代的小麦植株生长上 即表现出受到抑制,其程度随剂量的增加而增加。当剂量达到1600rad时,辐照当代的存活率便明显 减少,并达到了接近于萌发种子辐照的半致死剂量水平。 从电子射线辐照的小麦M_2代发生变异分离表明,电子射线对小麦种子的诱变具有变异谱较少,变 异频率较高的效应。按穗行变异统计,其平均突变频率为3.5%,而在产生变异的穗行内,突变频率范围为 2.6~6.1%。 相似文献
18.
V. Emir Kafadar A. Necmeddin Yazici R. Güler Yildirim 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(19):3337-3346
In the given study; the effects of heating rates on the dose response characteristics of CaF2:Dy (TLD-200), CaF2:Tm (TLD-300) and CaF2:Mn (TLD-400) crystals have been investigated using the dose dependence curve and dose response function f(D). It was observed from the dose response functions that the linearity and behaviour of the TL glow peaks of TLD-200 and TLD-400 are affected, but the TLD-300 is not affected from the heating rate. 相似文献
19.
20.
Tolga Depci Ay?en Y?lmaz 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2008,266(5):755-762
In this paper, the thermoluminescence (TL) dosimetric characteristics of Al-doped LiB3O5 compounds are presented. The powder samples were prepared by the solid-state reaction method and the formation of the compounds were confirmed by an X-ray diffraction study. The TL studies of undoped and Al-doped LiB3O5 samples showed similar glow curve structures. They have three TL glow peaks at about 60, 130 and 200 °C after heating at a constant heating rate of 1 °C/s. Their comparative TL studies indicated that 5 wt% Al-doped LiB3O5 compound was approximately 240 times more sensitive than undoped compound. The TL emission spectra of Al-doped LiB3O5 showed a maximum band at around 520 nm. The main dosimetric characteristics, which are namely the TL dose response, TL sensitivity, fading, minimum detectable dose, reproducibility, precision of dose measurement and annealing procedure, indicated that Al-doped LiB3O5 sample, can be used in dosimetric applications. The trap parameters namely order of kinetics (b), activation energy (E) and frequency factor (s) associated with the glow peaks in beta irradiated undoped and Al-doped LiB3O5 samples were obtained by glow curve deconvolution (GCD) program. 相似文献