共查询到19条相似文献,搜索用时 46 毫秒
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热释光探测器在脉冲硬X射线能谱测量中的应用 总被引:1,自引:0,他引:1
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。 相似文献
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为了研究强激光与固体靶相互作用产生的电离辐射危害,本文在星光Ⅲ300TW强激光装置上开展了一系列激光打靶实验。实验使用的激光功率密度为5×10~(18)~4×10~(19)W/cm~2,激光脉冲能量为60~153J,靶为直径1mm、厚度1mm的Ta圆柱,本文分别对X射线剂量、X射线能谱和超热电子能谱进行了测量。实验结果表明,测量到的单发最大X射线剂量约为16.8mSv,靠近激光传播方向(0°),距靶50cm处;激光0°方向的X射线剂量随激光功率密度的增加而显著增加,激光90°方向的X射线剂量随激光功率密度的变化相对较小;测量到的X射线能谱可大致用含有两个X射线温度的指数分布函数描述,其中0°方向测量到的X射线温度为0.4~1.15 MeV,90°方向测量到的X射线温度为0.25~0.54 MeV;实测超热电子温度与Wilks定标率符合较好。 相似文献
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随着空间时间的到来,人类已超越了大气层的屏障,开始了全波段天文观测。X射线、γ射线天文观测十分活跃,硕果累累。为了用高空技术气球这一有效运载工具进行空间硬X射线天文观测,我们研制了一个球载硬X射线谱仪。其主探测器是采用逃逸门技术的高气压氙多丝正比室,可探测15—200keV能区的硬X射线能谱。其数据获取系统的球载部分配合专用电子学电路对探测器信号实现逃逸门判选和处理,还对谱仪工作状况及环境的监测量进行模数变换,并把经过初步处理的数据以一定格式编排,经二次频率调制后由发射机发回地面。 由于该系统的球载部分工作于高空低气压、高辐射本底和强噪声的恶劣环境,环境温 相似文献
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本文提供了北京正负电子对撞机同步辐射光束线上X射线能谱的首次测量结果,文章对探测器和谱仪系统、测量方法及数据分析予以扼要的描述。 相似文献
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A method is given for calculating the form of pole surfaces for creating a magnetic field with an azimuthal variation of given depth and with a certain law of change of the mean field intensity along the radius. Experiments are described on the modeling of a magnetic field of a 1 1/2-meter cyclotron with azimuthal variation of the magnetic field. 相似文献
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A study has been made of the movement of ions in a cyclotron with azimutha variation of the magnetic field of the sector type. Methods are given which can be used to calculate the period of rotation, the frequencies of the vertical and horizontal oscillations and also the least required voltage on the dees. The method of calculating the voltage is also suitable for an ordinary cyclotron. 相似文献
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Polarization rotation of a probe pulse by the target is observed with the Faraday rotation method in the interaction of an intense laser pulse with a solid target.The rotation of the polarization plane of the probe pulse may result from a combined action of fused silica and diffused electrons.After the irradiation of the main pulse,the rotation angle changed significantly and lasted ~2 ps.These phenomena may imply a persistent magnetic field inside the target.An analytical model is developed to explain the experimental observation.The model indicates that a strong toroidal magnetic field is induced by an energetic electron beam.Meanwhile,an ionization channel is observed in the shadowgraph and extends at the speed of light after the irradiation of the main beam.The formation of this ionization channel is complex,and a simple explanation is given. 相似文献
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本文试图采用基于边界积分方程的一种边界分元的数值计算方法——边界元法,来分析我所2×6MV串列加速器的束流光学元件的电磁场。因为该方法不同于有限差分法和有限单元法的新方法,而且它具有以下优点:边界无法所依据的数学原理简单、易懂,便于推广应用;数值计算精度高;目前广泛应用的有限单元法和有限差分法都属于‘域法’,即在整个求解域里划分成许多细小的单元或网格,然后把各单元或网格换成简单的等价模型,再把它们联系起来。而边界元法只需要在边界上剖分、离散。因此,解算一个问题所要的方程组少,输入数据简单等。 相似文献
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A. Timm B. Strocka 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1985,12(4):479-485
(Y, La)3(Fe, Ga)5O12 epitaxial garnet films on (111) Gd3Ga5O12 substrates irradiated with 238U ions of 1.4 MeV/u specific energy in the dose range 1010 cm?2 to 3 × 1011 cm?2 were measured by means of Rutherford backscattering and double-crystal X-ray diffraction before and after thermal annealing in oxygen. The nuclear track diameter of 10 nm confining a cylindrical volume of highly disordered material caused by each ion impact has been deduced from the comparison of the backscattering spectra of the irradiated and unirradiated film areas. The fraction of randomly backscattered ions due to the irradiation-induced damage as well as the lattice expansion perpendicular to the crystal surface caused by irradiation-induced lateral compressive stress are proportional to the ion dose. After thermal annealing the comparison of the almost identical backscattering yield of the irradiated areas and the unirradiated film regions demonstrates a nearly perfect recrystallization of the damaged track volumes. 相似文献
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利用多毛细管准直器测量X射线光源焦斑尺寸 总被引:1,自引:1,他引:0
设计了一种测量X射线光源焦斑尺寸的方法:多毛细管准直器法。整体玻璃毛细管X射线准直器是由数105根内径为几微米的单玻璃毛细管组成的X射线光学器件,X射线光源发出的发散X射线光束被多毛细管准直器约束后变为准平行束。准平行束的截面直径是X射线光源焦斑直径的函数,通过测量准平行束不同位置处的截面直径,利用线性拟合可得到X射线光源的焦斑直径。分别利用多毛细管准直器法和常用的小孔成像法测量了同一微焦斑X射线光源的焦斑直径,测量结果分别为60.8和59.4μm。多毛细管准直器法对焦斑直径在亚微米量级或更小X射线源的焦斑尺寸测量中将显示出更多的优势。 相似文献
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The Radiation Bioengineering Laboratory at Seoul National University (SNU) operates a user-constructed hard X-ray irradiation facility for radiation biology and radiation therapy physics studies. The system package of YXLON model 450-D08 operating at the anode voltage of up to 450 kV is a key part of the facility, which enables in vitro cell irradiation and animal irradiation for in vivo studies. In this article, dose delivery in the hard X-ray irradiation facility was characterized in terms of the dose vs. operational parametric combination of the facility. The operational parameters included beam tube anode voltage, beam tube current, irradiation time, and beam exit-to-sample distance. Bremsstrahlung X-rays at energy below approximately 20 keV were filtered out by a 3 mm-thick aluminum plate fitted over the 5 mm-thick beryllium window. Gafchromic EBT films were used as radiation sensor materials in dose measurement. The characterization was validated via experimental observation of the in vitro biological responses of cells to radiation exposure. The biological responses obtained using the new hard X-ray irradiator were highly comparable with those obtained using a commercial gamma-ray irradiator. 相似文献