^(90)Sr/^(90)Y放射性激发等离子体隐身研究  

Investigation of plasma stealth excited by ^(90)Sr/^(90)Y

作　　者：朱家柱 刘伟[1] 崔驰[1] 王翔[1] 黄玉安[2] 张瑞利[1] 唐涛[1] 黄润生[1] 

机构地区：[1]南京大学物理学院,南京210093 [2]南京工程学院材料工程学院,南京211167

出　　处：《核技术》2014年第3期19-23,共5页Nuclear Techniques

基　　金：国家863计划(No.2006AA03Z458);国家自然科学基金(No.50977042;10904061)资助

摘　　要：依据90Sr/90Y的β衰变电子能谱分布,并考虑空气中电子扩散与复合规律,计算出不同活度的放射源致空气电离的电子密度分布;再利用WKB(Wentzel-Kramers-Brillouin)方法计算了涂覆90Sr/90Y的无限大金属板激发等离子体对不同入射角度、不同频率电磁波的反射率。当放射源的活度为3.7×1010Bq·cm-2和3.7×1011Bq·cm-2时,对垂直入射的1.5GHz电磁波的反射率分别为-2.2 dB和-7.45 dB。在1–100GHz范围内,反射率随入射电磁波频率的上升单调上升,随入射角度的上升单调下降。Background： Plasma stealth is one of the most important branches of the electromagnetic stealth technology. β -ray could ionize the air and excite the plasma. Under certain conditions, the plasma has stealth effect to the radar wave. Purpose： The aim is mainly to investigate the plasma stealth excited by 90Sr/90Y. Methods： We calculated the density distribution of the plasma excited by 90Sr/90Y with different radioactivity through configuring the weighting factor based on the decay energy spectrum of 90Sr/90Y with the electron diffusion and recombination in the air taken into consideration, and obtained the reflectivity of the plasma that was excited by infinite metal plate coated with 90Sr/90Y to electromagnetic waves with different incident angles and frequencies using the WKB （Wentzel-Kramers-Brillouin） method. Results： The reflectivity of the plasma with the radioactivity being 3.7×10^ 10Bq.cm-2 and 3.7×10^11 Bq.cm-2 to the vertically incident electromagnetic wave of 1.5 GHz could reach -2.2 dB and -7.45 dB respectively. Conclusion： In the range of 1-100 GHz, the reflectivity increases monotonically with the frequency, while decreases monotonically with the increase of incident angle. The stealth effect of the plasma excited by 90Sr/90Y with a certain radioactivity is of significance.

关 键 词：等离子体 电子密度 反射率 隐身技术 放射性激发 

分 类 号：TL99[核科学技术—核技术及应用] O571.322[理学—粒子物理与原子核物理]