CAJ | 학술논문

高能带电粒子与航天器介质材料相互作用引起的深层带电现象,一直是威胁航天器安全运行的重要因素之一.考虑入射电子在介质中的电荷沉积、能量沉积分布以及介质中的非线性暗电导和辐射诱导电导,建立了介质深层充电的单极性电荷输运物理模型.通过求解电荷连续性方程和泊松方程,可以得出不同能量(0.1—0.5 MeV)电子辐射下,低密度聚乙烯(厚度为1 mm)介质中的电荷输运特性.计算结果表明,不同能量的电子辐射下,介质充电达到平衡时,最大电场随入射能量的增加而减小;同一能量辐射下,最大电场随束流密度的增大而增加.入射电子能量较低时(0.3 MeV),最大电场随束流密度的变化趋势基本相同.具体表现为:当束流密度大于3×10?9 A/m2时,最大场强超过击穿阈值2×107 V/m,发生静电放电(ESD)的可能性较大.随着入射电子能量的增加,发生静电放电(ESD)的临界束流密度增大,在能量为0.4 MeV时,临界束流密度为6×10?8 A/m2.当能量大于等于0.5 MeV时,在束流密度为10?9—10?6 A/m2的范围内,均不会发生静电放电(ESD).该物理模型对于深入研究深层充放电效应、评估航天器在空间环境下深层带电程度及防护设计具有重要的意义.
고능대전입자여항천기개질재료상호작용인기적심층대전현상,일직시위협항천기안전운행적중요인소지일.고필입사전자재개질중적전하침적、능량침적분포이급개질중적비선성암전도화복사유도전도,건립료개질심층충전적단겁성전하수운물리모형.통과구해전하련속성방정화박송방정,가이득출불동능량(0.1—0.5 MeV)전자복사하,저밀도취을희(후도위1 mm)개질중적전하수운특성.계산결과표명,불동능량적전자복사하,개질충전체도평형시,최대전장수입사능량적증가이감소;동일능량복사하,최대전장수속류밀도적증대이증가.입사전자능량교저시(0.3 MeV),최대전장수속류밀도적변화추세기본상동.구체표현위:당속류밀도대우3×10?9 A/m2시,최대장강초과격천역치2×107 V/m,발생정전방전(ESD)적가능성교대.수착입사전자능량적증가,발생정전방전(ESD)적림계속류밀도증대,재능량위0.4 MeV시,림계속류밀도위6×10?8 A/m2.당능량대우등우0.5 MeV시,재속류밀도위10?9—10?6 A/m2적범위내,균불회발생정전방전(ESD).해물리모형대우심입연구심층충방전효응、평고항천기재공간배경하심층대전정도급방호설계구유중요적의의.
The interactions between high-energy charged particles and spacecraft insulating materials can cause deep dielectric charging and discharging, leading to spacecraft anomalies. In this paper, we establish a unipolar charge transport physical model of deep dielectric charging, according to the charge distribution and energy deposition of incident electrons and nonlinear dark conductivity and radiation induced conductivity (RIC) of material. Under the irradiation of electrons with different energies (from 0.1 to 0.5 MeV), the charge transport process of low density polyethylene (LDPE) can be obtained through solving the charge continuity equation and Poisson’s equation. The calculation results show that the maximum electric field decreases with the increase of radiation electron energy. When radiation electron energy is less than 0.3 MeV, the distribution of the maximum electric field is similar to the change of the electron beam density. When the electron beam density is more than 3×10?9 A/m2, the maximum electric field will be greater than breakdown threshold (about 2 × 107 V/m), and it has higher risk of electrostatic discharge (ESD). With the increase of incident electron energy, the critical electron beam density will increase. When the radiation electron energy is 0.4 MeV, the critical electron beam density is 6×10?8 A/m2. When the radiation electron energy is more than 0.5 MeV, it seems that no electrostatic discharge (ESD) will occur in a range from 10?9 to 10?6 A/m2. The physical model has the great significance for further studying deep dielectric charging, evaluating the charged degree of spacecraft in space environment and designing protection devices.