共查询到18条相似文献,搜索用时 78 毫秒
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重点开展了稳态、瞬态X射线辐照引起的金属氧化物半导体(CMOS)器件剂量增强效应relative dose enhancement effect(RDEF)研究.通过实验给出辐照敏感参数随总剂量的变化关系,旨在建立CMOS器件相同累积剂量时Χ射线辐照和γ射线辐照的总剂量效应损伤等效关系.在脉冲X射线源dense plasma focus(DPF)装置上,采用双层膜结构开展瞬态翻转增强效应研究,获得了瞬态翻转剂量增强因子.这些方法为器件抗X射线辐照加固技术研究提供了实验技术手段.
关键词:
X射线
剂量增强因子
总剂量效应
剂量率效应 相似文献
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当X射线射入不同材料组成的界面时, 在低Z材料的一侧将产生剂量增强。介绍了界面剂量增强效应的基本原理, 并用MCNP蒙特-卡洛程序计算了钨-二氧化硅、钽-二氧化硅界面的剂量增强因子。计算结果表明在X射线能量为100~150keV时,界面附近二氧化硅一侧存在较大的剂量增强。 相似文献
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同步辐射(软X射线,紫外)辐照农作物的生物效应研究 总被引:6,自引:0,他引:6
同步辐射的紫外辐照萌动麦种子的辐射敏感性为:大麦大于冬麦,大麦大于春麦。在3.5-22heVX射线辐照干麦种子的两次重复实验中,其辐射敏感性的次序发生了变化;0.6-3keV超软X射线辐照干麦种子时,当代幼苗出现了40-90%的“条状叶绿素缺失”的变异,这在其他射线辐照中未曾见过,是首次发现的生物效应。 相似文献
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在同步辐射X射线成像中,时常会出现对比度不高或对比度不均匀的问题,这将导致图像中样品的一些细节信息难以被观察和分析。针对这一问题,提出一种X射线图像对比度增强的算法。该算法以同态滤波为核心,结合图像降噪预处理及灰度调整,以现图像的对比度增强,并提高图像质量。编写程序实现该算法,并通过对分辨率靶图像和海洋鱼类样品的X射线图像进行测试。结果表明,该算法可以很好地增强灰度分布不均匀的低对比度X射线图像,使样品信息显示更清晰,灰度分布更均匀。同时,对X射线图像的降噪效果明显。 相似文献
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在北京同步辐射装置(BSRF)1W1B光束线和XAFS实验站上国内首次建立了硬X射线波段的磁圆二色实验(XMCD)方法. 以单晶金刚石作为相位延迟片, 在透射劳埃(Laue)模式下, 利用衍射双折射效应, 将入射的单色线偏振光转变为相应的左旋和右旋圆偏振光, 测量磁化样品对左旋和右旋圆偏振光吸收的差异, 获得了XMCD信号. 本实验使用透射方法测量了Pt-Fe合金Pt L2,3边的XMCD, 获得了XMCD信号. XMCD实验方法的建立, 为研究磁性材料尤其是磁性薄膜材料的电子结构和磁结构提供了实验基础. 相似文献
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Study of total ionizing dose radiation effects on enclosed gate transistors in a commercial CMOS technology 下载免费PDF全文
This paper studies the total ionizing dose radiation effects on MOS
(metal-oxide-semiconductor) transistors with normal and enclosed gate
layout in a standard commercial CMOS (compensate MOS) bulk process.
The leakage current, threshold voltage shift, and transconductance of
the devices were monitored before and after $\gamma $-ray
irradiation. The parameters of the devices with different layout
under different bias condition during irradiation at different total
dose are investigated. The results show that the enclosed layout not
only effectively eliminates the leakage but also improves the
performance of threshold voltage and transconductance for NMOS
(n-type channel MOS) transistors. The experimental results also
indicate that analogue bias during irradiation is the worst case for
enclosed gate NMOS. There is no evident different behaviour observed
between normal PMOS (p-type channel MOS) transistors and enclosed
gate PMOS transistors. 相似文献
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Ryan Brown Moeava Tehei Sianne Oktaria Adam Briggs Callum Stewart Konstantin Konstantinov Anatoly Rosenfeld Stephanie Corde Michael Lerch 《Particle & Particle Systems Characterization》2014,31(4):500-505
This article pioneers a study into the use of the tantalum pentoxide nanoceramics as novel candidates for dose enhancement radiotherapy. It is revealed that a significant induced dose enhancement on radioresistant cancer cells expose to tantalum pentoxide nanoparticles and irradiated with 10 MV. In this study, in vitro experiments are performed. The radiobiological endpoint is clonogenic survival. We exposed 9L gliosarcoma cells to the nanoparticles at 50–500 μg mL?1 range and observed concentration‐dependent toxicity. Irradiation of the exposed and unexposed cells with 10 MV X‐ray photons reveals a sensitization enhancement ratio of 1.33. The associated cell survival curves demonstrate a significant change in shape, indicative of increased lethality of the local radiation environment. We postulate that this enhancement is primarily due to secondary electrons produced from photoelectric interaction and pair production, with backscattering on nanoparticle aggregates leading to increased radiobiological effectiveness. 相似文献
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研究了X射线荧光光谱检测多层薄膜样品的增强效应。根据多层膜中的X荧光强度理论计算公式编写了计算机程序,并计算了Zn/Fe和Fe/Zn双层膜样品中不同薄膜厚度时Fe Kα的一次荧光强度、二次荧光强度、二次荧光与一次荧光强度比以及二次荧光在总荧光强度中比例。研究发现,在多层膜样品的X射线荧光分析中,激发条件不变的情况下,元素谱线的一次荧光相对强度、二次荧光相对强度和二次荧光在总荧光强度中所占比例都随薄膜厚度及位置的变化而变化。当Fe和Zn层厚度相同时,随厚度的变化,对于Fe/Zn样品,Fe Kα二次荧光强度占总荧光强度最高为9%,而对于Zn/Fe样品这一比例最高可达35%。 相似文献
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The intensity of the luminescence generally increases with radiation dose and measurement of these phenomena can be used to characterise the degree of dependence on beta doses. In this study, in order to test whether this is a significant problem on the optically stimulated luminescence (OSL) studies, the radiation dose response of the OSL signal from samples of chlorides contained in feldspars have been investigated by irradiating the samples with beta doses. The infrared-emitting diodes were used with a wavelength of (880±80) nm, and an IRSL (infrared stimulated luminescence) intensity parametres, m, was described and found m = 1±0.03. 相似文献