重离子和脉冲激光模拟单粒子翻转阈值等效性研究

根据重离子和脉冲激发诱发单粒子翻转机理,分析了重离子和脉冲激光模拟单粒子翻转阈值（激光能量与重离子线性能量转移（LET））等效方法，得出脉冲激光与重离子单粒子翻转阈值等效计算公式。应用实验室的激光模拟单粒子效应试验系统，开展了几种器件和集成电路的单粒子翻转实验研究。利用获得的计算公式计算激光等效LET阈值，并与国内外重离子实测数据进行比较。结果表明，脉冲激光能量等效LET阈值与重离子试验LET阈值较为一致。     

电流型PWM控制器单粒子脉冲瞬态效应的试验研究

采用理论分析与试验对比的方式,对脉宽调制(Pulse Width Modulation,PWM)控制器的脉冲激光模拟单粒子瞬态(Single Event Transient,SET)效应的等效性进行研究。对常用的电流型PWM控制器采用脉冲激光进行照射试验,通过改变激光能量得到不同条件下的试验数据,并与重离子照射条件下的试验数据进行对比。试验结果证实线状能量传递值LET(Linear Energy Transfer)=65.2 Me V·cm2·mg-1的868.3 Me V Xe重离子与波长1.064μm、能量为1–2 n J的脉冲激光产生的SET效应最为接近。试验结果为采用脉冲激光对同类型PWM控制器进行模拟SET试验提供了数据支撑。     

光电耦合器的单粒子瞬态脉冲效应研究

利用脉冲激光模拟单粒子效应实验装置研究光电耦合器HCPL-5231和HP6N134的单粒子瞬态脉冲(SET)效应.实验获得了相关器件的单粒子瞬态脉冲波形参数与等效LET的关系,并甄别出器件SET效应的敏感位置,初步分析了SET效应产生的机理.利用脉冲激光测试了光电耦合器的SET宽度与等效LET的关系,并尝试测试了两种光电耦合器的SET效应的截面,其中,HCPL-5231的实验结果与其他文献利用重离子加速器得到的数据符合较好,验证了脉冲激光测试器件单粒子效应的有效性.     

反熔丝型现场可编程门阵列单粒子锁定实验研究

利用单粒子效应脉冲激光和锎源模拟试验系统,对反熔丝型A42MX36现场可编程门阵列进行了单粒子锁定敏感性评估试验.脉冲激光试验确定了单粒子锁定脉冲激光阈值能量及其等效重离子LET、锁定电流等敏感参数;锎源模拟试验确定了单粒子锁定截面.对试验中出现的由单粒子绝缘击穿和单粒子伪锁定引起的电流跃变现象进行了讨论和分析.     

脉冲激光模拟单粒子效应研究

脉冲激光在集成电路和器件单粒子效应(Single Event Effect,SEE)研究中有着广泛的应用。与重离子源相比,通过脉冲激光诱发SEE更容易获得空间信息和时间信息。本文介绍激光诱发SEE的产生机理、模拟试验设置以及线性能量传输(Linear Energy Transfer,LET)算法,通过皮秒激光诱发单光子与飞秒激光诱发双光子的模拟试验,对SEE现象发生时电压响应与能量的关系进行分析,验证了脉冲激光在SEE研究中的有效性和可行性。     

高LET值束流产生技术研究进展

随着器件抗辐射加固性能的提高,在进行地面模拟试验时对所用重离子的能量及其在材料中的线性能量传输（LET）的要求也越来越高。为了提高串列加速器束流能量及其在材料中的LET,最切实可行的办法是使用高剥离电荷态离子。     

14 nm FinFET器件单粒子瞬态特性研究

为评估鳍式场效应晶体管（FinFET）的本征抗辐射能力,本文通过三维工艺计算机辅助设计（TCAD）仿真研究了14 nm FinFET工艺的单粒子瞬态（SET）特性。研究结果表明,在不同的线性能量传输（LET）值及不同的入射位置下,FinFET器件具有不同的单粒子敏感性。SET脉冲宽度随LET值的增大而展宽。此外,SET特性与粒子轰击位置的关系呈现出复杂性。对于低LET值（LET≤1 MeV·cm2/mg）,SET特性与重离子的入射位置具有很强的依赖性;对于高LET值（LET＞10 MeV·cm2/mg）,由于加强了衬底的电荷收集,SET特性与粒子轰击位置的依赖性减弱。     

脉冲激光和重离子辐照FPGA产生的多位翻转效应的比较

以SRAM型FPGA为试验对象,研究脉冲激光模拟重离子产生单粒子多位翻转效应的可行性。FPGA的多位翻转依据其物理位置关系的不同分为3种类型:同帧同字节、同帧相邻字节和相邻帧。针对Virtex-ⅡFPGA分别进行脉冲激光与重离子的单粒子多位翻转效应的测试,对比脉冲激光和重离子在Virtex-ⅡFPGA产生多位翻转的类型、多位翻转的物理位置关系。结果表明,脉冲激光触发的Virtex-ⅡFPGA的多位翻转物理位置关系与重离子相同,对比脉冲激光与重离子的饱和翻转截面发现,应用脉冲激光和重离子得到的Virtex-Ⅱ饱和翻转截面基本一致,表明脉冲激光可模拟重离子研究Virtex-ⅡFPGA的多位翻转效应。     

p-n结脉冲激光诱发电荷收集试验研究

测量了脉冲激光诱发半导体p-n结的瞬态脉冲电流,研究瞬态脉冲幅值和收集电荷与能量、偏压及入射位置的相关性。研究结果表明,瞬态脉冲信号幅值和收集到的总电荷随脉冲激光能量的增大而增多,与激光能量呈指数关系;收集电荷随偏压而增大;敏感区内的收集电荷数相差不大,远离敏感区的收集电荷明显减小。另外,将研究结果与重离子试验数据进行比对,两者有一定的相似性,但电荷收集脉冲幅值、脉冲波形有一定的差异。其结果为深入研究激光模拟单粒子效应技术奠定了基础。     

重离子单粒子效应实验研究

在HI—l3串列加速器上建立了对微电子器件进行单粒子效应模拟实验的辐照和检测技术。利用该Q3D磁谱仪获得种类和能量单一、强度分布均匀且足够弱的重离子辐照源，利用散射室内的半导体探测器和焦面上的位置灵敏半导体探测器监测辐照离子。用该装置和技术测量了在8个传能线密度(LET)值的重离子辐照下引起的几个存储器器件的单粒子翻转（SEI）截面o(L)。从测得的o(L)——LET曲线，结合空间重离子和质子辐照环境模型以及离子与微电子器件相互作用模型计算，预言了器件在空间的单粒子翻转率。     

高能重离子在聚合物中的辐照效应研究

Ion irradiation of polymers can induce irreversible changes in their macroscopic properties such as electrical and optical properties and the surface-related mechanical properties. Electronic excitation, ionization, chains scission, cross-links and mass losses are accepted as the fundamental events that give rise to the observed macroscopic changes. Detailed and systematic study of radiation induced effects in polymers enriches not only the knowledge of ion-material interactions but also supplies new bases for polymeric materials synthesis through ion-beam technologies. Previous work has concentrated mainly on effects induced by low-ionization particles such as γ-rays and electrons. Since 1980,s the application of high energy heavy ion accelerators enables the use of high energy heavy ion as an irradiation source, and many new and exciting effects and phenomena have been revealed.Energetic heavy ions in matter lose energy mainly through electronic excitation and ionization. Compared to low-ionization particles, high energy heavy ion possesses higher LET(linear energy transfer) values which can reach several to several tens keV/nm. As most of the primary ionizations and excitations occur close to the ion trajectory in a core of a few nanometers in diameter, a continuous damaged zone along the ion path can be induced,in which all bonds inside the zone can be destroyed due to the high rate energy deposition. Studies on this particularity of high energy heavy ion irradiation and its effects in materials will cause great influence on industry as well as on our daily life.The previous work has revealed the great difference in the effects induced by high energy heavy ions compared to the other particles. It has been shown that under irradiation with lower LET particles gas release depends on molecular structure and material composition, whereas under irradiation with high LET particles, such as high energy heavy ions, it is not the case. Some materials that undergo degradation under γ-irradiation can be cross-linked by irradiation with high energy heavy ions. In some cases new molecular structures were induced by high energy heavy ions with sufficiently high LET values. In recent years we have irradiated polyethylterephthalate (PET), polystyrene (PS), polycarbonate (PC) and polyimide (PI) with high energy Ar, Kr, Xe and U ion beams.Chemical and physical changes of the materials induced by the high energy heavy ion beams were investigated by Fourier-transform infrared ray spectroscopy, ultraviolet and visible transmission spectroscopy and X-ray diffraction measurements, from which damage cross-sections of various functional groups were determined[1]. An energy loss threshold for damage of phenyl ring in PET has been derived and difference in amorphization of PET under high and low LET irradiations was observed. It is found that alkyne end groups can be induced in all the materials above a certain electronic energy loss threshold, which is found to be about 0.8 keV/nm for PS and 0.4 keV/nm for PC. The production cross-section of alkyne end group increases with increasing electronic energy loss and shows saturation at high electronic energy loss values.     

FPGA单粒子效应的脉冲激光试验方法研究

通过测试基于静态随机存储器（SRAM）的现场可编程门阵列（FPGA）芯片的单粒子效应,研究脉冲激光的试验方法,评估脉冲激光试验单粒子效应的有效性。研究表明,激光光斑聚焦深度和激光注量是影响脉冲激光单粒子效应试验的重要因素。试验发现,脉冲激光在较高能量时,单个激光脉冲会触发多个配置存储位发生单粒子翻转,造成芯片饱和翻转截面偏大。激光辐照芯片时,观察到芯片的内核工作电流以1～2 mA的幅度逐渐增加,在此期间器件工作正常。试验获得了Virtex 2 FPGA芯片的静态单粒子翻转截面和翻转阈值。通过对比激光与重离子的试验结果发现,二者在测试器件单粒子翻转方面基本一致,脉冲激光可有效研究芯片的单粒子效应特性。     

Heavy ion beam pumped lasers

Particle beams with energy per particle ranging from a few keV to greater than 1 GeV have been used to pump gas lasers. Well-focused high energy heavy ion beams have a short range, low range straggling and high specific energy loss which increases with the square of the effective charge. They can be used to pump a small cylindrical volume which can be well-matched to the optical axis of a laser resonator. Results obtained to date are described with both cw and pulsed particle beams; and possible extensions using heavy ion storage rings considered.     

Comparison among Methods for Evaluating Dose Equivalent in Pulsed and Mixed Radiation Field

In order to ascertain the accuracy and applicability of the method which was developed in the previous paper for evaluating the dose equivalent in a single-burst and mixed radiation field, a comparison with two other ones has been carried out. One is based on the measurement of the neutron energy spectrum with TOF system and the separate measurement of the absorbed doses with twin chambers. In the other, a tissue-equivalent proportional counter is used for measuring the LET distribution of the absorbed dose. The average quality factor has been evaluated in a pulsed and mixed field generated by an electron linear accelerator. A good agreement has been found among these methods.

A problem about the experimental determination of the dose equivalent index has also been discussed. It was pointed out that the average quality factor as a function of the depth in tissue could be regarded as characteristic of the mixed radiation field.     

光电耦合器4N49单粒子瞬态脉冲效应的试验研究

通过脉冲激光模拟单粒子效应,对光电耦合器4N49的单粒子瞬态脉冲（SET）效应进行了试验研究。在10V工作电压下,获取了4N49在特定线性能量传输（LET）值下的SET波形特征及其变化规律,得到了器件SET效应的等效LET阈值为10MeV•cm²•mg^-1,而饱和截面数值则高达1.2×10^-3cm²。试验验证了4N49的SET效应对后续数字电路的影响状况,定量研究了SET效应减缓电路的有效性,通过设计合理的电路参数可将器件在5V工作电压下的SET效应阈值由7.89MeV•cm²•mg^-1提高至22.19MeV•cm²•mg^-1。4N49的SET效应试验研究为光电耦合器SET效应的测试及防护措施的有效性验证提供了新的试验方法。     

IDT6116单粒子敏感性评估试验技术研究

为评估IDT6116SRAM单粒子敏感性,采用地面试验方法和地面试验系统,利用脉冲激光、重离子和²⁵²Cf源3种不同的地面模拟源,对IDT6116SRAM器件进行单粒子敏感性试验研究,并对3种不同的模拟源的试验结果进行等效性分析比较,同时进行总剂量效应对单粒子效应影响的试验研究。研究结果表明：IDT6116SRAM抗单粒子翻转和锁定的能力较强;接受一定辐照剂量后的试验样品对单粒子翻转更加敏感,且翻转阈值略有降低,翻转截面略有增大。     

3D visualization of heavy ion beam energy deposition in two different target shapes

Heavy ion beams have favorable energy deposition behavior because they can penetrate and deposit their energy well inside the target. Ion beams have potential uses in fields including heavy ion beam fusion, high-energy density physics and material processing. Intense heavy ion beams can generate high-energy density matter in the laboratory under extreme density and pressure conditions. Additionally, in heavy ion fusion, a stringent requirement for successful fuel ignition and sufficient fusion energy release is that the ion energy deposition profiles are calculated precisely in the energy absorber layer. In this work, the OK2 code was used to simulate the heavy ion beam energy deposition in various target materials, and a computer program was written to provide 3D visualization of the results. The heavy ion beams used in this work were composed of lead, uranium, and cesium ions with energies of 8 GeV and carbon ions with energies of 5 MeV. The targets included two shapes: a monolayer sphere that can be used in direct-driven fusion and a cylindrical shape that is common in indirectly driven heavy ion fusion.     

一种基于抗辐照体系架构的单粒子效应等效评估拟合算法

针对国内加速器辐照实验无法充分满足航天器单粒子抗辐照设计验证需求的问题,本文提出了一种单粒子效应抗辐照等效评估拟合算法模型。该算法模型基于抗辐照体系架构,构建可靠性贡献度耦合因子,获取单粒子效应下系统功能中断截面随粒子线性能量转移(LET)值变化的等效耦合关系,从而降低对辐照实验条件依赖,为航天器抗辐照设计验证提供更多基准数据。最终通过实验数据分析比对,该算法模型可用于辐照实验数据的评估拟合,提升了航天器系统抗辐照设计可靠性评估效率。