CMOS器件60Coγ射线、电子和质子电离辐射损伤比较

利用TRIM95蒙特卡罗软件计算了质子在二氧化硅中的质量阻止本领和能量沉积,比较了质子在二氧化硅中的电离阻止本领与核阻止本领,分析了质子在材料的表面吸收剂量与灵敏区实际吸收剂量的关系.利用60Coγ射线、1MeV电子和2-9 MeV质子对CC4007RH和CC4011器件进行辐照实验,比较60Coγ射线和带电粒子的电离辐射损伤情况.实验结果表明,60Coγ射线、1MeV电子和2-7MeV质子辐照损伤效应中,在0V栅压下可以相互等效;在5V栅压下,以60Coγ射线损伤最为严重,1MeV电子的辐射损伤与60Coγ射线差别不大,9MeV以下质子辐射损伤总是小于60Coγ射线,能量越低,损伤越小.     

CMOS器件60Co γ射线、电子和质子电离辐射损伤比较

利用TRIM95蒙特卡罗软件计算了质子在二氧化硅中的质量阻止本领和能量沉积，比较了质子在二氧化硅中的电离阻止本领与核阻止本领，分析了质子在材料的表面吸收剂量与灵敏区实际吸收剂量的关系.利用⁶⁰Co γ射线、1MeV电子和2—9 MeV质子对CC4007RH和CC4011器件进行辐照实验，比较⁶⁰Co γ射线和带电粒子的电离辐射损伤情况.实验结果表明，⁶⁰Co γ射线、1MeV 电子和2—7MeV质子辐照损伤效应中，在0V栅压下可以相互等效； 关键词： γ射线 电子 质子 辐射损伤     

辐照导致硼硅酸盐玻璃机械性能变化

为了模拟研究高放废物玻璃固化体在处置过程中因辐照导致的机械性能变化,本文采用5 MeV Xe离子和1.2 MeV电子辐照硼硅酸盐玻璃,利用纳米压痕技术表征了辐照前后样品的硬度和模量,并利用傅里叶变换衰减全反射红外光谱测试,研究了辐照导致玻璃机械性能变化的微观机理.结果表明:当能量沉积达到6.6×10~(21)keV/cm~3时,Xe离子辐照样品的硬度和模量下降都达到饱和,其中硬度下降约24%,模量下降约7.4%;电子辐照后样品的硬度和模量也有轻微下降,但在实验所用剂量范围内硬度和模量下降未出现饱和现象,当吸收剂量达到最大值(1×10~9 Gy)时,硬度和模量分别下降约4.7%和2.9%.分析表明:Xe离子辐照后样品的恢复阻力增大,韧性提高,整体机械性能提升,而电子辐照后样品的机械性能无明显变化.研究结果证明了离子辐照导致玻璃机械性能变化的主要因素是离子在样品中的核能量沉积.     

红外光吸收研究35MeV/u Ar离子辐照半晶质聚酯膜引起的效应

35MeV/u Ar离子在室温下辐照了多层堆叠的半晶质聚酯膜,采用傅立叶转换的红外光吸收技术分析和研究了由辐照引起的化学键断裂及其对离子剂量、离子在样品中的平均电子能量损失和吸收剂量的依赖性.结果表明,辐照导致聚酯膜中发生了明显的化学键断裂,断键过程主要发生在反式构型的乙二醇残留物和苯环的对位上,苯环的基本结构在辐照中变化较小.断键不仅强烈地依赖于离子的照射剂量,而且还跟样品中电子能量沉积密切相关,明显的断键发生在4.0MGy以上的吸收剂量.     

辐照电子在光纤芯处能量沉积的计算

为了用尽可能低的辐照电子能量在光纤芯处形成大的性质改变,模拟了0.1～1 MeV能量的电子辐照二氧化硅.发现每一特定能量的电子辐照二氧化硅时,在其中有个能量沉积最快的位置.计算得到0.447 4 MeV能量的电子在单模光纤中心能量沉积最快,分析发现对于这个能量的电子多数可以穿透到光纤芯处,电子能量在光纤芯处的沉积主要是由于电子能量的减小造成的.这些结果可为用电子辐照光纤制作光器件时的初始电子能量选择提供参考.     

纳米多晶体的热力学函数及其在相变热力学中的应用

以往关于纳米材料热力学的研究，绝大多数以界面的热力学函数表征整体纳米材料的热力学性质，这种近似处理，对于尺寸超过几十纳米的较粗纳米材料，在相变热力学中对特征转变温度和临界尺寸等重要参量的预测，将导致很大误差. 应用“界面膨胀模型”和普适状态方程，研究了纳米晶界的热力学特性，进一步发展了纳米晶整体材料热力学函数的计算模型，给出了单相纳米多晶体的焓、熵和吉布斯自由能随界面过剩体积、温度，以及晶粒尺寸发生变化的明确表达式. 以Co纳米晶为例，分析了界面与整体纳米多晶体热力学函数的差异，确定了相变温度与晶粒尺寸的依赖关系，以及一定温度下可能发生相变的临界尺寸. 关键词： 纳米多晶体 热力学函数 相变热力学     

Bi_2WO_6光催化剂的γ射线辐射效应（英文）

本文首次研究了高能辐射(γ射线)对Bi_2WO_6纳米晶体结构和光催化性能的影响.结果表明,尽管高能辐射不会改变Bi_2WO_6纳米晶体的形貌,但是Bi_2WO_6粉末的颜色在高吸收剂量辐照(507 kGy)后发生了明显的变化,并且辐照后Bi_2WO_6的XRD谱图也显示,随着吸收剂量的增加,(113)晶面对应的2θ从28.37°移到28.45°,说明晶格参数在γ射线辐照下还是发生了细微的变化.XPS表征结果证明,Bi_2WO_6晶体结构的变化源于高剂量辐射下氧空位缺陷的产生.Bi_2WO_6纳米晶体的禁带宽度(E_g)随吸收剂量的增加也出现减小的趋势.用水溶液中亚甲基蓝的可见光照分解反应作为模型反应考察了辐照后的Bi_2WO_6纳米晶体的光催化活性,结果表明,辐照后的Bi_2WO_6纳米晶体的光催化活性随着吸收剂量的增加而逐渐升高.将经过反应后的Bi_2WO_6纳米晶体再次回收,进行循环催化,发现这些辐照后的Bi_2WO_6纳米晶体在三次循环使用后光催化性能仍然能够保持,说明高能辐射产生的氧空位缺陷具有良好的稳定性.     

不同粒子辐射条件下CC4013器件辐射损伤研究

本文采用60 MeV Br离子、5 MeV质子和1 MeV电子等三种辐射源, 针对CC4013型互补金属氧化物半导体器件(complementary metal oxide semiconductor, CMOS)进行辐射损伤研究. 通过Geant4程序计算了该器件电离辐射吸收剂量与芯片厚度的关系, 经过计算, 在相同注量下, 60 MeV Br离子的电离吸收剂量最大, 1 MeV电子产生的电离吸收剂量最小. 应用Keithley4200-SCS半导体特性分析仪在原位条件下研究了CC4013器件电性能参数随辐射吸收剂量的变化关系. 测试结果表明, 相同电离辐射吸收剂量下, 1 MeV电子对CC4013器件的阈值电压参数影响最大, 5 MeV质子其次, 60 MeV Br离子的影响最弱. 关键词： CMOS器件 高能带电粒子 电离辐射 辐射损伤     

离子注入金红石单晶生成的金属Ni纳米晶的磁学性能研究

研究了能量为64keV、注量1×1017cm-2的Ni离子注入金红石TiO2单晶制备的植入金属纳米晶的微观结构和磁学性能。注入层的结构和磁学性能采用透射电子显微分析（TEM）和超导量子干涉磁强计（SQUID）进行分析。结果表明，金红石单晶中有尺寸为3～18nm的金属Ni纳米晶生成，注入区域基体明显非晶化。10K温度下金属Ni纳米晶的矫顽力约为16.8kA·m-1，比Ni块材的矫顽力大。样品的零场冷却/有场冷却（ZFC/FC）曲线表明，金属Ni纳米晶的截止温度约为85K。     

高能质子在散裂靶中的能量沉积计算与实验验证

高能质子在散裂靶中的能量沉积是散裂靶中子学研究的重要内容之一,准确掌握高能质子在散裂靶中引起的能量沉积分布与瞬态变化是开展散裂靶热工流体设计的重要前提.本文采用MCNPX,PHITS与FLUKA三种蒙特卡罗模拟程序,计算并比较了高能质子入射重金属铅靶、钨靶的能量沉积分布及不同粒子对总能量沉积的占比贡献;针对高能质子入射金属钨靶的能量沉积实验数据空白,采用热释光探测器阵列测量了250 MeV质子束入射厚钨靶的能量沉积分布,实验结果表明蒙特卡罗模拟程序在散裂靶中能量沉积的计算结果具有较高的可靠性.     

用可调探测深度电子能量损失谱与俄歇电子能谱研究Pb/Ni(001)界面

本工作用可调探测深度电子能量损失谱(ELS)与俄歇电子能谱(AES)研究Pb在Ni(001)表面的生长过程。发现Pb是一层一层地在表面生长的,即按Franck-van der Merwe(F-M)模式生长。当Pb的覆盖度大于1单层(ML)时,Pb的6s能带对应的电子能量损失峰开始出现,当Pb的覆盖度为3ML时,Pb的体等离激元的损失峰已相当明显。在Pb的蒸镀过程及随后的整个退火过程中,Pb的体等离激元峰,6s能带峰和Ni的3p能带峰的峰位与峰宽均保持与纯金属相同的值,也没有出现新的体等离激元峰。由此说明P     

5 MeV Proton irradiation effects on 200 GHz silicon–germanium heterojunction bipolar transistors

The total dose effects of 5?MeV proton and Co-60 gamma irradiation in the dose range from 1 to 100?Mrad on advanced 200?GHz Silicon–Germanium heterojunction bipolar transistors (SiGe HBTs) are investigated. The SRIM simulation study was conducted to understand the energy loss of 5?MeV proton ions in SiGe HBT structure. Pre- and post-radiation DC figure of merits such as forward- and inverse-mode Gummel characteristics, excess base current, DC current gain and output characteristics were used to quantify the radiation tolerance of the devices. The results show that the proton creates a significant amount of damages in the surface and bulk of the transistor when compared with gamma irradiation. The SiGe HBTs shows robust ionizing radiation tolerance even up to a total dose of 100?Mrad for both radiations.     

电子束辐照对GaN基LED发光性能的影响

研究了不同能量的电子束辐照对GaN基发光二极管(Light emitting diode,LED)发光性能的影响。利用实验室提供的电子束模拟空间电子辐射,对GaN基LED外延片进行1.5,3.0,4.5 MeV电子束辐照实验,并应用光致发光(Photoluminescence,PL)谱测试发光性能。结果表明:在1.5 MeV电子束辐照下,采用10 kGy剂量辐照时,LED的发光强度增加约25%;而在100 kGy剂量辐照时,LED的发光强度降低约16%。3 MeV的电子束辐照可使原来色纯度不高的LED的色纯度变好,而更高能量的辐照将会引起器件失效。     

Conductivity of irradiated Kapton in relation to energy loss of ions and electrons

Abstract

We have studied the effects of 2.5 MeV electron irradiation and ion (C, N, F, Si and Kr) bombardment on the electrical conductivity of a polyimide (Kapton-H) with ion energies ranging between 320 keV (N) and 1.25 GeV (Kr). In this wide range of situations we have tried to sort out the respective effects of nuclear and electronic excitation energy losses.

For all ion irradiation the conductivity is found to scale with the electronic excitation absorbed dose: i.e. a power law of conductivity versus absorbed dose with an exponent around 9 is observed. At a given absorbed dose (in Gray units) the efficiency of each ion to enhance conductivity is found to be proportional to the electronic energy loss; electrons are much less efficient than ions and thus collective excitations are required to achieve this process.

The nuclear energy loss can perhaps play some role at conductivities higher than 100 Ω^?1 m^?1, but its effects are negligible in the range explored here.     

Effect of 30 Mev Li 3+ ion and 8 MeV electron irradiation on n-channel MOSFETs

The effect of 30 v MeV Li 3+ ion and 8 v MeV electron irradiation on the threshold voltage ( V TH ), the voltage shift due to interface trapped charge ( j V Nit ), the voltage shift due to oxide trapped charge ( j V Not ), the density of interface trapped charge ( j N it ), the density of oxide trapped charge ( j N ot ) and the drain saturation current ( I D v Sat ) were studied as a function of fluence. Considerable increase in j N it and j N ot , and decrease in V TH and I D v Sat were observed in both types of irradiation. The observed difference in the properties of Li 3+ ion and electron irradiated MOSFETs are interpreted on the basis of energy loss process associated with the type of radiation. The study showed that the 30 v MeV Li 3+ ion irradiation produce more damage when compared to the 8 v MeV electron irradiation because of the higher electronic energy loss value. High temperature annealing studies showed that trapped charge generated during ion and electron irradiation was annealed out at 500 v °C.     

质子与中子辐照对电荷耦合器件暗信号参数的影响及其效应分析

对科学级电荷耦合器件(charge-coupled device, CCD)进行了质子和中子辐照试验及退火试验, 应用蒙特卡洛方法计算了质子和中子在CCD中的能量沉积, 分析了器件的辐射损伤机理. 仿真计算了N⁺埋层内沉积的位移损伤剂量, 辐照与退火试验过程中主要考察暗信号的变化规律. 研究结果显示, 质子与中子辐照均会引发暗信号退化, 其退化的规律与位移损伤剂量变化一致; 退火后, 质子辐照所致CCD暗信号大幅度恢复, 其体暗信号增加量占总暗信号增加量的比例最多为22%; 中子辐照引发的暗信号增长主要为体暗信号. 质子和中子在N⁺埋层产生相同位移损伤剂量的情况下, 两者导致的体暗信号增长量相同, 质子与中子辐照产生的体缺陷对体暗信号增长的贡献是同质的.     

高能重离子辐照的ODS铁素体钢脆化效应研究

与传统的铁素体钢相比,氧化物弥散强化(ODS) 的铁素体钢具有更优的耐高温和抗辐照性能,近年来成为先进核能装置重要的候选结构材料。在HIRFL 的扇聚焦型回旋加速器(SFC) 材料辐照终端,对一种氧化物弥散强化(ODS) 铁素体钢MA956 进行了高能Ne 离子辐照实验,旨在研究级联碰撞损伤和惰性气体原子注入条件下该材料力学性能的变化。利用辐照终端的能量衰减装置将SFC出口123.4 MeV的离子能量分解为介于38.5~121.0 MeV之间的30 个入射能量值,并通过双面辐照在厚度60 μm的样品中均匀产生了损伤。辐照剂量为9x1016 ions/cm2,在样品中的平均位移损伤为0.7 dpa,注入的Ne原子浓度为350 appm。辐照期间样品温度保持在440 ℃附近。对辐照前后的样品分别在室温和500 ℃下进行了小冲杆试验(Small-punchTest),获得了辐照前后样品的加载位移曲线,由此得到该辐照条件下样品的延性损失为18%~26%。通过扫描电子显微镜观察了断口形貌和厚度变化,估算了样品的等效断裂应变和断裂韧性。结果表明,MA956 钢经过高能Ne离子辐照后等延伸率减小,断裂韧性降低,样品发生了一定的脆化。透射电镜结果说明氧化物弥散相界面处微空洞的形成可能是导致脆化的原因。Oxide dispersion strengthened (ODS) ferritic steels have better high-temperature creep rupture strength and higher irradiation resistance than conventional ferritic steels, and show high prominence of application in advance nuclear reactors. Their stability under high-dose radiation conditions needs to be clarified. In the present study, a commercial ODS ferritic steel MA956 were irradiated with high 20Ne ions at a terminal chamber of the Sector-focused Cyclotron (SFC) at HIRFL (Heavy-ion Research Facility in Lanzhou). With the energy gradient degrader of the irradiation chamber, the primary energy (123.4 MeV) of the Ne-ion was dispersed into 30 different energies between 38.5~ 121.0 MeV, which resulted in a plateau distribution of lattice damage in the specimens. The specimens were irradiated from both sides so that the whole 60 m thickness was nearly uniformly damaged. The specimen temperature was maintained around 440 ℃ during the irradiation. The irradiation dose is about 9x1016 ions/cm2, corresponding to a damage level of 0.7 dpa and a Ne concentration of 350 appm. The specimens before and after irradiation were tested with the Small-punch Test technique, at room temperature and 500 ℃, respectively. The fracture morphology was observed by scanning electron microscopy.The results show that MA956 underwent some loss of ductility and fracture toughness after the irradiation with high-energy 20Ne ions. It may be ascribed to the formation of nano-scale cavities at the oxides/matrix interfacesin the ODS steel specimens under irradiation .     

35MeV/uAr离子辐照聚酯膜引起的效应研究

采用多种手段研究了 35Me V/u的 Ar离子辐照聚酯 (PET)膜产生的微观结构变化 .结果表明 ,辐照使聚酯的化学键断裂并产生了炔端不饱和基团和自由基 .断键主要发生在乙二醇残留物、苯环的对位和酯的 C— O键上 .随着吸收剂量的增加 ,材料的结晶度逐渐降低 ,由原始的41 .7%减至最高辐照量时的 1 5.0 % .研究发现 ,聚脂的非晶化转变截面与电子能损呈线性关系 ;断键和非晶化效应主要取决于样品的吸收剂量 ,并存在一个约 4.0 MGy的阈值.Stacked polyethylene terephthalate films were irradiated with 35 MeV/u Ar ions at room temperature. The ion induced effects were studied by ultraviolet visible spectrometer, Fourier transform infrared spectroscopy, X ray diffractometer, X ray photoelectron spectroscopy, electron spin resonance spectroscopy and differential scanning calorimetry. Bond breaking and the formation of alkyne end groups and free radicals were observed. The bond breaking processes occurred mainly...     

Response of CaSO4:Dy phosphor based TLD badge system to high energy electron beams from medical linear accelerator and estimation of whole body dose and skin dose

Response of thermoluminescent dosimeter (TLD) badge based on CaSO₄:Dy phosphor to high energy electron beams from medical linear accelerators was simulated using FLUKA Monte Carlo code and experimentally verified. This study was carried out in order to determine the response of TL discs under different filter regions of the TLD badge and their ratios under different irradiation conditions in the energy range 6–20 MeV of high energy electron beams. It was found that the response of TL disc under metal filters of the TLD badge (D1) is always higher than the response of the TL discs under Polystyrene filter (D2) and open window (D3) and its response was found to decrease with increase in the energy of the electron beam. Estimation of whole body dose and skin dose including its error was carried out as an extension of the present study in case of accidental exposure of radiation worker to high energy electron beam.