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61.
KJ-9驾驶仪电磁兼容问题 总被引:1,自引:0,他引:1
本文主要介绍了为提高KJ-9驾驶仪的电磁兼容性能所采取的一些措施,以及在实践中碰到的问题的分析和解决的办法。 相似文献
62.
要提高电子仪器可靠性,对电磁干扰和抗干扰技术需要进一步研究。有关电子仪器电磁屏蔽的机理和设计方法在本文中作了介绍。 相似文献
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64.
A. Emmanuel J. Raghavan R. Harris P. Ferguson 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
The Canadian Space Agency (CSA) has proposed a Polar Communications and Weather (PCW) satellite mission, in conjunction with other partners. The PCW will provide essential communications and meteorological services to the Canadian Arctic, as well as space weather observations of in situ ionizing radiation along the orbit. The CSA has identified three potential Highly Elliptical Orbits (HEOs) for a PCW satellite constellation, Molniya, Modified Tundra and Triple Apogee (TAP), each having specific merits, which would directly benefit the performance/longevity of a PCW spacecraft. Radiation shielding effectiveness of various materials was studied for the three PCW orbit options to determine the feasibility of employing materials other than conventional aluminium to achieve a specified spacecraft shielding level with weight savings over aluminium. It was found that, depending on the orbit-specific radiation environment characteristics, the benefits of using polyethylene based materials is significant enough (e.g., 22% in Molniya for PE at 50 krad TID) to merit further investigation. 相似文献
65.
张永维 《中国空间科学技术》1989,9(5):25-28
本文简述了空间辐射粒子对卫星运行的影响和利用计算机进行的三维屏蔽分析。三维模式的结果更为精确,可以用于对二维模式的评价。 相似文献
66.
Electrostatic space radiation shielding 总被引:2,自引:0,他引:2
Ram K. Tripathi John W. Wilson Robert C. Youngquist 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
For the success of NASA’s new vision for space exploration to Moon, Mars and beyond, exposures from the hazards of severe space radiation in deep space long duration missions is ‘a must solve’ problem. The payload penalty demands a very stringent requirement on the design of the spacecrafts for human deep space missions. The exploration beyond low Earth orbit (LEO) to enable routine access of space will require protection from the hazards of the accumulated exposures of space radiation, Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE), and minimizing the production of secondary radiation is a great advantage. There is a need to look to new horizons for newer technologies. The present investigation revisits electrostatic active radiation shielding and explores the feasibility of using the electrostatic shielding in concert with the state-of-the-art materials shielding and protection technologies. The full space radiation environment has been used, for the first time, to explore the feasibility of electrostatic shielding. The goal is to repel enough positive charge ions so that they miss the spacecraft without attracting thermal electrons. Conclusions are drawn for the future directions of space radiation protection. 相似文献
67.
NASA 二级轻气炮设备简介 总被引:4,自引:0,他引:4
随着人类航天活动日益频繁,地球轨道上空间碎片总数逐年增长。航天器表面空间碎片防护工作受到各航天大国的高度重视。航天器针对毫米级空间碎片主要采用被动防护方式。超高速撞击实验是防护方案设计工作的基础。NASA 在毫米级弹丸超高速撞击实验中采用的主要发射装置为二级轻气炮。本文对美国 NASA 和相关单位二级轻气炮设备及其未来发展趋势进行简要介绍,同时对我国相关单位超高速撞击实验设备进行分析,并对发展趋势进行讨论。 相似文献
68.
Comparisons of several transport models in their predictions in typical space radiation environments 总被引:1,自引:0,他引:1
Z.W. Lin J.H. Adams Jr. A.F. Barghouty S.D. Randeniya R.K. Tripathi J.W. Watts P.P. Yepes 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
We have used several transport codes to calculate dose and dose equivalent values as well as the particle spectra behind a slab or inside a spherical shell shielding in typical space radiation environments. Two deterministic codes, HZETRN and UPROP, and two Monte Carlo codes, FLUKA and Geant4, are included. A soft solar particle event, a hard solar particle event, and a solar minimum galactic cosmic rays environment are considered; and the shielding material is either aluminum or polyethylene. We find that the dose values and particle spectra from HZETRN are in general rather consistent with Geant4 except for neutrons. The dose equivalent values from HZETRN and Geant4 are not far from each other, but the HZETRN values behind shielding are often lower than the Geant4 values. Results from FLUKA and Geant4 are mostly consistent for considered cases. However, results from the legacy code UPROP are often quite different from the other transport codes, partly due to its non-consideration of neutrons. Comparisons for the spherical shell geometry exhibit the same qualitative features as for the slab geometry. In addition, results from both deterministic and Monte Carlo transport codes show that the dose equivalent inside the spherical shell decreases from the center to the inner surface and this decrease is large for solar particle events; consistent with an earlier study based on deterministic radiation transport results. This study demonstrates both the consistency and inconsistency among these transport models in their typical space radiation predictions; further studies will be required to pinpoint the exact physics modules in these models that cause the differences and thus may be improved. 相似文献
69.
提出了一种采用s参数法结合CST-MS软件进行航天器屏蔽度仿真分析和预测的方法。在航天器舱体结构内的发射天线和舱体结构外的接收天线处分别设置端口,通过计算端口间的s参数来分析计算舱体结构的屏蔽度,并将仿真分析结果与实测结果进行对比。对比结果表明,仿真计算结果与实测验证结果基本上是一致的,充分验证了采用s参数法结合CST-MS软件对屏蔽度仿真分析,具有很好的实用性和计算精度。这种方法应用于航天器设备级和系统级,能够显著降低航天器电磁兼容性(EMC)分析的难度,并能在一定程度上简化航天器前期设计中EMC试验验证的需求。 相似文献
70.