Subjects: Geosciences >> Space Physics submitted time 2017-03-10
Abstract：介质-导体相间结构是航天器部件的常见结构。为研究影响此种结构深层充电特性的内在因素，设计了不同构型的实验样品，利用Sr90放射源模拟空间高能电子环境对样品进行了深层充电辐照实验，测量了充电电位的差异。并借助深层充电三维仿真软件计算了此种结构在不同几何构型情况下的深层充电电位、电场分布。实验和仿真结果表明，介质最高表面电位以及介质内部最大电场均与介质宽度和高度呈正相关。其它条件不变时，介质越宽，或越高于导体表面，发生放电的风险就越高。在介质与导体侧面存在微小缝隙情况下，介质内最大电场显著增强，易发生内部击穿。而在介质与导体之间的真空间隙内，电场很容易超过击穿阈值，在一定的触发条件下放电风险很大。航天工程应用中为降低此种结构深层充放电的风险，在满足绝缘性能及其他要求的前提下应尽量减小介质的宽度，降低介质与导体间高度差，并确保介质与导体侧面接触良好。
Peer Review Status:
Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： Russia's Mars probe Phobos-Grunt together with China's first Mars probe Yinghuo-1 were launched into Low Earth Orbit (LEO) on November 9, 2011. Unfortunately, the main probe failed to fire its thrusters and transfer its orbit as planned after 159 minutes, eventually the trip to Mars was terminated. The most likely cause of the accident investigated by Russian Space Agency (RSA) was that RAM chips in onboard control computers worked wrong when hit by cosmic heavy charged particles, which sequently led to the two computers restart and eventually disturbed the probe totally. However experts on satellite radiation hardness casted lot of doubt on the statement that LEO probe can be effected by Single-Event Effects (SEE) resulting from space radiation particles in so short period of time. Based on information of the victim RAM components disclosed by RSA, experiment tests and calculations were performed for K6R4016V1D chip to predict SEE rate when applied in LEO. Finally, possibility for SEE to cause the failure of Phobos-Grunt probe was discussed.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-03
Abstract： The pulsed laser facility for single event upset(SEU)sensitivity mapping was utilized to study SEU sensitivity mapping of SRAM IDT71256.To avoid the block of the metal layer in the front side of integrated circuit,the backside testing method was used.The experiment results show that the SEU sensitivity of the SRAM cell depends on the pattern of data stored in the memory cell.The SEU sensitivity mapping could be used to construct the corresponding SEU cross section,which is validated by the heavy ion beam test result.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-03
Abstract： The classical approaches for single event latchup (SEL) rate prediction are based on the rectangular parallelepiped (RPP) model of only one sensitive volume. However, the experiment results of SEL sensitivity mapping of static random access memory (SRAM) show that the device has not only one sensitive volume (SV). The in-flight SEL rate of the device was corrected using the experiment results of pulsed laser SEL sensitivity mapping of SRAM K6R4016V1D.The SEL sensitivity maps of the SRAM by pulsed laser were first obtained and then the SV number of the device was calculated. The SEL rates of the device were predicted and discussed for different space orbits, radiation particles, SV thicknesses and SV number in particular. The results show that SEL rate caused by heavy ion decreases with SV number. The correction of the SV number is essential for SEL rate due to proton direct ionization; otherwise, the contribution of direct ionization of protons to SEL rate would be greatly overestimated.
Peer Review Status:Awaiting Review
Hits
Hits
Downloads
Comment