伸杆对星载电场探测仪的影响研究

通过一定长度的伸杆使电场探头与卫星本体保持一定的距离,可以减小卫星本体鞘层对电场测量的影响.但卫星在运行时伸杆与电场探头之间可能存在电位差,从而为电场测量引入误差.该文利用卫星与等离子体相互作用模拟软件(SPIS)并结合法国DEMETER卫星的伸杆和电场探头模型,模拟了伸杆与探头之间不同电位差对电场探头收集电子流的影响,模拟表明当伸杆电位低于探头电位时,对电场测量影响较小,当伸杆电位高于探头电位时,对电场测量影响较大,且电位差越大,影响越显著.当等离子体浓度增大即德拜长度减小时,伸杆电位形成的鞘层减小,因此伸杆对电场测量的影响比低浓度时有所减小.

Study of the Influence of Booms on Spaceborne Electric Field Sensors

The electromagnetic interferences generated by the spacecraft or other payloads to the spaceborne electric field sensor can be significantly reduced by introduction of booms. However, the boom potential may differ from the sensor; so the boom sheath may extend over the sheath of the sensor probe and affect the electric field measurement. In order to evaluate the amount of disturbance, SPIS (Spacecraft Plasma Interaction System) and Particle in Cell method are used to compute the collected current of the sensor probe under the condition of different potential between the sensor probe and the boom. The plasma parameters, boom and electric field sensor models are got from the DEMETER satellite. The results indicate that when the boom potential is lower than the sensor probe, it introduces small disturbances on the sensor operation, when boom potential is higher than the sensor probe, there is a noticeable change in the sensor current collected. And the higher potential difference between the boom and sensor, the more disturbances will be introduced. With the enlarging of the plasma density, the disturbance is reduced because of the small Debye length.