共查询到19条相似文献,搜索用时 484 毫秒
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为研究放射性核素固化介质备选矿物锆英石的抗γ射线辐照结构稳定性,以澳大利亚锆英石为研究对象,通过60Co源γ射线辐照装置对样品施以1728 kGy的γ射线辐照.利用X射线荧光光谱仪、扫描电子显微镜和X射线衍射仪对样品的元素含量、γ射线辐照前后的微观形貌及物相变化进行表征,同时利用Rietveld方法对γ射线辐照前后的样品进行了结构精修.结果表明:澳大利亚锆英石经1728 kGy剂量的γ射线辐照后未发生物相变化,射线辐照前后样品的晶胞参数仅发生了10-4 量级的变
关键词:
锆英石
γ射线
辐照
Rietveld结构精修 相似文献
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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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本文采用γ射线、高能电子和中子对Ti/4H-SiC肖特基势垒二极管(SBD)的抗辐射特性进行了研究.研究发现对于γ射线和1 MeV电子辐照,-30 V辐照偏压对器件的辐照效应没有明显的影响.经过1 Mrad(Si)的γ射线或者1×l013 n/cm2的中子辐照后,Ti/4H-SiC肖特基接触都没有明显退化;经过3.43×1014 e/cm2的1 MeV电子辐照后Ti/4H-SiC的势垒高度比辐照前轻微下降,这是由于高能
关键词:
碳化硅
肖特基
辐照
偏压 相似文献
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研究了PNP输入双极运算放大器LM837在1 MeV电子和60Coγ源两种不同辐射环境中的响应特性和变化规律. 分析了不同偏置状态下其电离辐照敏感参数在辐照后三种温度 (室温, 100 ℃, 125 ℃)下随时间变化的关系, 讨论了引起电参数失效的机理. 结果表明: 1 MeV 电子辐照LM837引起的损伤主要是电离损伤, 并且在正偏情况下比60Coγ源辐照造成的损伤大; 辐照过程中, 不同辐照源正偏条件下的偏置电流变化都比零偏时微大; 在不同的辐照源下, LM837辐照后的退火行为都与温度有较大的依赖关系, 而这种关系与辐照感生的界面态密度增长直接相关.
关键词:
PNP 输入双极运算放大器
60Coγ源')" href="#">电子和60Coγ源
偏置条件
退火 相似文献
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给出了不同集成度16K—4Mb随机静态存储器SRAM在钴源和北京同步辐射装置BSRF3W1白光束线辐照的实验结果;通过实验在线测得SRAM位错误数随总剂量的变化,给出相同辐照剂量时20—100keVX光辐照和Co60γ射线辐照的剂量损伤效应的比例因子;给出集成度不同的SRAM器件抗γ射线总剂量损伤能力与集成度的关系;给出不同集成度SRAM器件的X射线损伤阈值.这些结果对器件抗X射线辐射加固技术研究有重要价值. 相似文献
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对于相同制作工艺的NPN锗硅异质结双极晶体管(SiGe HBT), 在不同辐照剂量率下进行60Co γ射线的辐照效应与退火特性的研究. 测量结果表明, 两种辐照剂量率下, 随着辐照总剂量增加, 晶体管基极电流增大, 共发射极电流放大倍数降低, 且器件的辐照损伤、性能退化与辐照剂量率相关, 低剂量率下辐照损伤较高剂量率严重. 在经过与低剂量率辐照等时的退火后, 高剂量率下的辐照损伤仍较低剂量率下的损伤低, 即待测SiGeHBT具有明显的低剂量率损伤增强效应(ELDRS). 本文对相关的物理机理进行了探讨分析.
关键词:
锗硅异质结双极晶体管
低剂量率辐照损伤增强
辐照效应 相似文献
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The effect of γ-ray irradiation on the magnetic properties of NdFeB and Fe–Cr–Co permanent magnets has been investigated. The magnetic flux loss of two kinds of magnets before and after irradiation was measured. Results show that the effect of γ-ray irradiation on the magnetic properties of sintered NdFeB is not so obvious as that on Fe–Cr–Co magnet. Irradiation-induced damage from γ-ray for the Fe–Cr–Co magnets was characterized for the first time. The decline of permanent magnetic properties of Fe–Cr–Co magnet induced by γ-ray irradiation is reversible except for the maximum energy product (BH)max. The difference of coercivity mechanism between these two kinds of permanent magnets is responsible for the different dependence of magnetic properties loss induced by γ-ray irradiation. 相似文献
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Three experimental techniques sensitive to the sign of the Dzyaloshinskii-Moriya interaction are discussed: neutron diffraction, Mössbauer γ-ray diffraction, and resonant x-ray scattering. Classical examples of hematite (α-Fe2O3) and MnCO3 crystals are considered in detail. 相似文献
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Two kinds of time differential Mössbauer spectra of57Co-labelled Co(BrO3)2·6H2O were measured at room temperature by delayed coincidence technique, i.e., one was the delayed coincidence between 122 keV γ ray and 14.4 keV γ ray (γ, γ-ray coincidence), and another was the coincidence between 6.3 keV KX ray and 14.4 keV γ ray (X, γ-ray coincidence). The time dependence of chemical states of57Fe-species were observed on γ, γ-ray and X, γ-ray coincidence Mössbauer spectra. The relative area intensities of57Fe(II) observed on the X, γ-ray coincidence spectra were larger than those on the γ, γ-ray coincidence spectra on every time windows. 相似文献
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Shokrollah Rezaie-Serej Gilbert R. Hoy R. Dean Taylor 《Hyperfine Interactions》1992,71(1-4):1425-1432
Our search for the Mössbauer Effect in109Ag using the self-absorption method is summarized. Measurements have been made using two different109Cd-doped single-crystal silver samples. In our method the silver Kα and Kδ x rays, as well as, the 88-keV γ rays are considered. The results are analyzed using the ratio of the number of x-ray to γ-ray counts. A positive effect is observed. 相似文献
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A. A. Saafan M. A. Sakran M. M. Abou-Sekkina 《Isotopes in environmental and health studies》2013,49(11-12):502-505
Extensive measurements have been carried out on cellobiose and cellulose molecules in the solid state comprising infrared and electronic absorption spectra both before and after exposure to an absorbed energetic γ-ray dose (3.0 × 103 rad). These materials were chosen as representatives of di- and polysaccharides. They have hydrogen bonding of variant origins as they have cyclic structures and the magnitude of γ-radiation damage were evaluated in each case. Gamma radiolytic oxidation mechanism was established for both di- and poly-saccharides investigated. Es wurden ausgedehnte Messungen an Cellobiose- und Cellulose-Molekülen im festen Zustand ausgeführt, die einer Gammastrahlnng (3,0 · 103 rad) ausgesetzt waren und von denen vor bzw. nach dieser Bestrahlung Infrarot- und Elektronenabsorptionsspektren aufgenommen wurden. Diese Verbindungen warden als Modellsubstanzen für Di- und Polysaccharide gewählt. Sie besitzen Wasserstoffbrückenbindungen der verschiedensten Art und haben auch cyclische Strukturen. Die Gröβe der Gammastrahlenzerstörung wurde für alle diese Fälle abgeschätzt. Ein Mechanismus der radiolylischen Oxidation wurde für die untersuchtten Di- und Polysaccharide aufgestellt. 相似文献
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Recently evidence has emerged for enormous features in the γ-ray sky observed by the Fermi-LAT instrument: bilateral "bubbles" of emission centered on the core of the Galaxy and extending to around ± 10 kpc from the Galactic plane. These structures are coincident with a nonthermal microwave "haze" and an extended region of x-ray emission. The bubbles' γ-ray emission is characterized by a hard and relatively uniform spectrum, relatively uniform intensity, and an overall luminosity 4×10(37) erg/s, around 1 order of magnitude larger than their microwave luminosity while more than order of magnitude less than their x-ray luminosity. Here we show that the bubbles are naturally explained as due to a population of relic cosmic ray protons and heavier ions injected by processes associated with extremely long time scale (? 8 Gyr) and high areal density star formation in the Galactic center. 相似文献
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Bhogi Jai Rama Satyanarayana Swamy Rangu Vijay Pamidi Ramesh Babu Bhaskar Sanyal Yerramreddy Gandhi Nalluri Veeraiah 《Ionics》2016,22(9):1625-1634
γ-Ray-induced dielectric dispersion in CaF2–B2O3–P2O5 glasses doped with different concentrations of CuO was investigated. The glass samples were exposed to γ-rays with dose varying within the range 0–10 kGy. The dielectric dispersion and spectroscopic properties were measured before and after γ-ray treatment. Additionally, thermoluminescence studies were performed on post-irradiated glass samples. The results of dielectric properties and dielectric breakdown strength indicated a substantial increase in the insulating strength of CuO containing glasses due to γ-ray irradiation. The analysis of these results together with UV-vis optical absorption, IR spectra, and thermoluminescence studies have indicated a gradual increase in the concentration of mono-valent copper ions due to γ-ray treatment of the glass network. The additional studies have confirmed that these Cu+ ions occupy network-forming positions, increase the polymerization of the borophosphate glass network, and facilitates for the increase of insulating strength of the titled glass. 相似文献
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A. M. Galper S. I. Suchkov N. P. Topchiev I. V. Arkhangelskaja A. I. Arkhangelskiy A. V. Bakaldin Yu. V. Gusakov O. D. Dalkarov A. E. Egorov V. G. Zverev V. V. Kadilin A. A. Leonov P. Yu. Naumov M. F. Runtso M. D. Kheymits Yu. T. Yurkin 《Physics of Atomic Nuclei》2017,80(6):1141-1145
The GAMMA-400 γ-ray telescope installed at the Russian space observatory is intended for precision measurements in the energy range of 20 MeV–1000 GeV of γ-ray emission (with the angular and energy resolutions several times better than that of current γ-ray telescopes) from discrete sources; measurement of the energy spectra of Galactic and extragalactic diffuse γ-ray emission; studies of γ-ray emission from the active Sun; and measurements of fluxes of γ-ray emission and electron–positron cosmicray component, which are probably associated with the annihilation or decay of dark-matter particles. 相似文献