KEY PHYSICAL PROBLEMS IN DEEP DIELECTRIC CHARGING ON SATELLITES

Deep dielectric charging （DDC） is one of the key factors inducing malfunctions and failures on geo-synchronous satellites. In this paper, the mam problems such as charging time, electric field distribution, as well as influences on DDC-induced maximum field by shield, dielectric thickness and grounding patterns are studied in detail, and some results of computer simulation are introduced for the plannar model. In the meantime, some preliminary measures for DDC protection are re-commended accordingly. The charging time depends on both dielectric parameters and flux of high ener-getic electrons in the space environment. For epoxy, a kind of usually used dielectric material on satellites, the charging time is in the order of hours. The electric field distribution in the dielectric is determined by the grounding pattern. For the case grounded on single side, the maximum field generally appears on the grounded side with the other side having zero field. While for the case grounded on both sides, both sides have maximum fields, with values smaller than single-grounded case. Moreover, the maximum field in the dielectric is related to the thickness of the dielectric itself and the applied shield. The maximum field increases with the dielectric thickness to a saturated value, and decreases with the shield thickness, however, contribution of the shield over a certain thickness is neglegible.