Collisionless braking of dust particles in the electrostatic field of planetary dust rings
Collisionless braking of dust particles in the electrostatic field of planetary dust rings
复制标题
行星尘环静电场中尘粒的无碰撞制动
DOI：
10.1088/0031-8949/45/5/012
复制
发表时间：
1992
期刊：
影响因子：
2.9
通讯作者：
T. Nitter
中科院分区：
文献类型：
--
作者：
O. Havnes;T. Aslaksen;F. Melandsø;T. Nitter
我们表明，在静电场中沿周期性轨道运动的灰尘测试粒子（如行星环引起的轨道）在没有任何灰尘与灰尘碰撞的情况下也会经历净减速。当移动的灰尘进出不同电子和离子密度的区域（由于环静电势的变化）时，其上变化的电荷将与平衡电荷异相，从而导致颗粒的净制动。这种效应已被证明可以抑制静电支持的尘埃环的相干振荡[1]，并抑制固体表面等离子体鞘中悬浮尘埃粒子的振荡[2]。我们证明，这种效应将导致行星环内部随机速度的衰减，其速度在许多情况下可能比尘埃碰撞造成的速度快得多。对于灰尘测试颗粒相对于环的适度径向运动，我们还发现可以在环边缘处有效地制动和拾取颗粒。我们得出的结论是，当随机速度的无碰撞制动优于尘埃制动时，环的塌陷率可能会增加到其最小静电厚度，并且环的径向稳定性也可能会增加。环径向边缘处的拾取效应是形成其结构的潜在重要因素。
We show that a dust test particle moving in a periodic orbit in electrostatic fields, as those due to planetary rings, will experience a net deceleration also in the absence of any dust-dust collisions. The varying charge on the moving dust, as it moves in and out of regions of differing electron and ion densities (due to changes in the ring electrostatic potential), will be out of phase with the equilibrium charge in a way which leads to a net braking of the particle. This effect has been shown to damp the coherent oscillations of electrostatically supported dust rings [1] and to damp the oscillatons of levitated dust particles in plasma sheaths at surfaces of solid bodies [2]. We show that this effect will lead to a damping of internal random velocities in a planetary ring, at a rate which in many cases can be much faster than that due to dust-dust collisions. For moderate radial motions of dust test particles relative to a ring we also find that there can be an efficient braking and pick-up of particles already at the ring edges. We conclude that when the collisionless braking of random velocities dominates over dust-dust braking, an increased rate of collapse of the ring to its minimum electrostatic thickness may occur and possibly also an increased radial stability of the ring. The pick-up effect at the ring radial edges is a potentially imortant factor in forming their structure.
影响因子：
2.8
作者：
HAVNES, O;GOERTZ, CK;IP, W
通讯作者：
IP, W