Papers Published

1. Haff, P.K. and Eviatar, A. and Siscoe, G.L., Ring and plasma: the enigmae of Enceladus, Icarus (USA), vol. 56 no. 3 (1983), pp. 426 - 38 [0019-1035(83)90164-1] .
   (last updated on 2007/04/10)

   Abstract:
   The E ring associated with the Kronian moon Enceladus has a lifetime of only a few thousand years against sputtering by slow corotating O ions. The existence of the ring implies the necessity for a continuous supply of matter. Possible particle source mechanisms on Enceladus include meteoroidal impact ejection and geysering. Estimates of ejection rates of particulate debris following small meteroid impact are on the order of 3×10^-18 g cm^-2 sec^-1, more than an order of magnitude too small to sustain the ring. A geyser source would need to generate a droplet supply at a rate of approximately 10^-16 g cm^-2 sec^-1 in order to account for a stable ring. Enceladus and the ring particles also directly supply both plasma and vapor to space via sputtering. The absence of a 60 eV plasma at the Voyager 2 Enceladus L-shell crossing such as might have been expected from sputtering, implies that the effective sputtering yield in the vicinity of Enceladus is about an order of magnitude less than the calculated value

   Keywords:
   planetary atmospheres;planetary rings;planetary satellites;plasma;Saturn;sputtering;