高速CMOS电路电离辐照损伤的剂量率效应

对国产加固５４ＨＣ０４高速ＣＭＯＳ电路进行了不同剂量率的辐照响应和室温退火特性研究。探讨了５４ＨＣ０４电路在不同剂量率辐照下的损伤机理和失效模式的差异及其对高速ＣＭＯＳ电路在辐射环境中应用可靠性的影响。     

闪烁体／光纤量能器的结构,材料和抗辐照能力

描述了闪烁体／光纤的不同结构和材料对量能器抗辐照能力的影响。用北京正负电子对撞机将～１ＧｅＶ电子束对五个量能器模型逐步辐照到１０ｋＧｙ或６０ｋＧｙ。通过对不同累积辐照剂量时各模型不同断面的光产额的测量，研究和比较了辐照引起的损伤及损伤后的恢复。     

双极晶体管瞬态辐射光电流分流补偿法及其实验研究

采用标准分立双极元件,对双极晶体管瞬态辐射光电流分流补偿法进行了实验验证。给出了双极晶体管瞬态辐射响应及光电流分流补偿原理,比较了带补偿与不带补偿电路的瞬态响应波形。实验结果对双极晶体管集成电路瞬态辐射加固具有指导意义。     

微波辐射对NaClO漂白麦草浆白度与硬度影响的研究

考察微波辐射对麦草浆漂白白度与硬度的影响。微波辐射影响微波辐射纸浆漂白白度与硬度的因素有3项：微波辐射时间、辐射功率、次氯酸钠用量。实验得到：随着微波辐射功率、时间、次氯酸钠用量增加自度升高硬度下降;与水浴的对比实验可见漂白纸浆达到相同白度时高锰酸钾值基本相同;漂白时间大大缩短至2mm。     

微波辐射对NaC1O漂白麦草浆白度与硬度影响的研究

考察微波辐射对麦草浆漂白白度与硬度的影响.微波辐射影响微波辐射纸浆漂白白度与硬度的因素有3项:微波辐射时间、辐射功率、次氯酸钠用量.实验得到:随着微波辐射功率、时间、次氯酸钠用量增加白度升高硬度下降;与水浴的对比实验可见漂白纸浆达到相同白度时高锰酸钾值基本相同;漂白时间大大缩短至2min.     

Axial ion–electron emission microscopy of IC radiation hardness

A new system for performing radiation effects microscopy (REM) has been developed at Sandia National Laboratory in Albuquerque. This system combines two entirely new concepts in accelerator physics and nuclear microscopy. A radio frequency quadrupole (RFQ) linac is used to boost the energy of ions accelerated by a conventional Tandem Van de Graaff–Pelletron to velocities of 1.9 MeV/amu. The electronic stopping power for heavy ions is near a maximum at this velocity, and their range is 20 μm in Si. These ions therefore represent the most ionizing form of radiation in nature, and are nearly ideal for performing single event effects testing of integrated circuits. Unfortunately, the energy definition of the RFQ-boosted ions is rather poor ( a few %), which makes problematic the focussing of such ions to the submicron spots required for REM. To circumvent this problem, we have invented ion electron emission microscopy (IEEM). One can perform REM with the IEEM system without focussing or scanning the ion beam. This is because the position on the sample where each ion strikes is determined by projecting ion-induced secondary electrons at high magnification onto a single electron position sensitive detector. This position signal is then correlated with each REM event. The IEEM system is now mounted along the beam line in an axial geometry so that the ions pass right through the electron detector (which is annular), and all of the electrostatic lenses used for projection. The beam then strikes the sample at normal incidence which results in maximum ion penetration and removes a parallax problem experienced in an earlier system. Details of both the RFQ-booster and the new axial IEEM system are given together with some of the initial results of performing REM on Sandia-manufactured radiation hardened integrated circuits.     

Dose rate effect on micro-structure and hardness of Hastelloy-N irradiated by Xe ions

Hastelloy-N alloys were irradiated by Xe⁺ with energies of 7 and 2 MeV at room temperature in order to investigate the effects of dose and dose rate on the change of micro-structure and nanohardness. Hardness was measured by nanoindentation, and micro-structure evolution and irradiation defects were identified by transmission electron microscopy (TEM) and positron annihilation coincidence Doppler broadening (CDB), respectively. The nanoindentation results showed that the hardness of alloys increased after irradiation, especially at a lower dose rate. At higher dose rate, TEM results indicated that irradiation defects were observed at first in this experiment, and the size of the defects increased, while their number density decreased as the dose increased. However, for a same total dose, the defects formed at a lower dose rate were larger, and their number density was also higher than that at a higher dose rate. Meanwhile, CDB analysis verified the growth of vacancy-type defects with increasing dose.     

Investigation of the radiation hardness on semiconductor devices using the ion micro-beam

Variation of the ion beam induced charge (IBIC) pulse heights due to ion irradiation was investigated on a Si pn diode and a 6H-SiC Schottky diode using a 2 Mev He⁺ micro-beam. Each diode was irradiated with a focused 2 MeV He⁺ micro-beam to a fluence in the range of 1×10⁹–1×10¹³ ions/cm². Charge pulse heights were analyzed as a function of the irradiation fluence. After a 2 MeV ion irradiation to the Si pn junction diode, the IBIC pulse height decreased by 15% at 9.2×10¹² ions/cm². For the SiC Schottky diode, with a fluence of 6.5×10¹² ions/cm², the IBIC pulse height decreased by 49%. Our results show that the IBIC method is applicable to evaluate irradiation damage of Si and SiC devices and has revealed differences in the radiation hardness of devices dependent on both structural and material.     

快速高准确度的闪烁探测技术

闪烁探测器具有探测效率高和适于多种条件下应用等优点。但在高计数率测量时,光电倍增管出现的疲劳现象难以克服,其长期稳定性也较差。 本文提出一种措施,使闪烁探测器在每秒10~5个计数脉冲下获得了高的精度和好的稳定性。这项技术已经应用于FT-1型核子低含沙量计中。经测试表明,当每次测量历时为100秒时该仪器的计数精度和8小时长期     

真空和辐射环境下的高低温系统

研究了在一定真空度(1Pa左右)和辐照环境(裂变碎片104s-1,中子104s-1)中获得高低温的方法,特别是低温(-55～20℃)的实现技术。研制出适应于锎源辐照测量系统的高低温装置及测量控制系统,温度范围:-100～125℃,控制精度:高温±1℃,低温±3℃。应用该系统开展了半导体存储器的重离子单粒子翻转截面随温度变化关系的研究,在国内首次得到了重离子单粒子翻转截面随温度变化的关系曲线。     

高计数率穆斯堡尔谱仪

本文论述了我们研制的高计数率穆斯堡尔谱仪,将它与常用穆斯堡尔谱仪作了比较,并利用512道,在道计数率超过20万次/h条件下,测量了磁带样品和考古样品的穆斯堡尔谱。     

Dose rate effects on the radiation induced oxidation of polyethylene

The yields and spatial distribution of the products arising from the in source oxidation of 50 μm LDPE films induced by 60-Co gamma radiations and by 300 kev electrons have been investigated as a function of the dose rate. The dose rate was found to have a strong influence on the reaction, the hydroperoxides and carbonyls yields at the lowest gamma dose rate of 0.04 kGy/h being decreased by a factor of about three with increasing the gamma dose rate up to 0.69 kGy/h and by a factor of about 30 when operating at the e-beam dose rate of 1.5 kGy/s. The carbonyls depth concentration profiles, the EPR measurements on radicals intermediates and the experiments of post-irradiation oxidation are consistent with the conclusion that, as far as the gamma irradiation is concerned, the observed dose rate effects cannot be imputed to oxygen diffusion control and/or to the chain branching via hydroperoxides decomposition coupled to the longer times between the initiation events. The hypothesis of the dose rate acting on the kinetic chain length of the radioxidation which in turn implies a substantially uniform distribution of radicals in the amorphous phase attained through spur expansion is proposed.     

高灵敏低源强微机核子秤的研制

介绍了基于闪烁探测器的微机核子秤的设计思想，组成及原理，系统采用高灵敏度的闪烁探测器，放射源的活度较低，嵌入式微机通过6个触模式按键操作，极为简便。     

Microstructural degradation mechanisms during creep in strength enhanced high Cr ferritic steels and their evaluation by hardness measurement

There are two creep regions with different creep characteristics: short-term creep region “H”, where precipitates and subgrains are thermally stable, and long-term creep region “L”, where thermal coarsening of precipitates and subgrains appear. In region “H”, the normalized subgrain size (λ-λ₀)/(λ^∗-λ₀) has a linear relation with creep strain and its slope is 10ε⁻¹. But, region L is the time range in which the static recovery and the strain-induced recovery progress simultaneously. In this region, the static recovery accelerates the strain-induced recovery, and subgrain size is larger than that line which neglects the contribution of the static recovery. In region “L”, the Δλ/Δλ^∗-strain present a linear relation with a slope 35ε⁻¹. There is a linear relation between hardness and subgrain size. Hardness drop, H₀ − H, as a function of Larson-Miller parameter can be a good measure method for assessment of hardness drop and consequently degradation of microstructure. Hardness drop shows an identical slope in creep region “H”, whereas hardness drop due to thermal aging and creep in region “L” show together a similar slope. In region “H”, degradation of microstructure is mainly due to recovery of subgrains controlled by creep plastic deformation, and precipitates do not have a major role. However, in creep region “L”, there are three degradation mechanisms that accelerate creep failure; (1) strain-induced recovery of subgrains due to creep plastic deformation, (2) static-recovery of subgrains and precipitates and (3) strain-induced coarsening of precipitates due to the appearance of static-recovery.     

Calculated radiation damage effects of high energy proton beams

The radiation damage effects produced by 600–800 MeV protons include displacement cascades, helium and hydrogen gasses and heavy impurities. These effects were calculated using the nucleon meson transport code for the nuclear reactions produced by the protons and the theory of Lindhard et al. for the resultant damage energy. Aluminum was chosen as the primary metal in this study as it is being used in proton irradiation experiments. Results are also reported for copper, type 316 stainless steel, titanium, vanadium, and molybdenum.     

Effect of high energy electron radiation on MIPB-impregnatedpolypropylene film

The effect of impregnating capacitor-grade polypropylene film with an aromatic hydrocarbon fluid is examined with a view towards assessing the response under radiation of the relevant properties of the film. Monoisopropyl biphenyl (MIPB)-impregnated polypropylene film was exposed in air to 1-MeV electrons at different dose rates and the post-radiation effects on the electrical, mechanical, morphological, and chemical properties were evaluated. The results obtained indicate that the oil-impregnated films remain relatively stable even at the highest dose of 10⁸ rads. This is in contrast to the results reported by the authors (ibid., vol.NS-34, no.6, p.1822-6, 1987) for dry polypropylene films which underwent degradation due to chain scission and oxidation. In the present instance, it is believed that impregnation of the film has inhibited the diffusion of oxygen and consequently favored crosslinking. The chemical characterizations as well as the changes in some of the measured properties of the film are seen to corroborate this belief