Study of the plasma performance of the EFD apparatus for the CSES mission

The Electric Field Detector (EFD) for space ionosphere electric field measurement is described. The EFD is one of the payloads of the China Seismo-Electromagnetic Satellite (CSES) space mission. The EFD measures the variation of the ionosphere electric field due to perturbations from solar, seismic and anthropic phenomena in a wideband from dc up to 3.5 MHz. The EFD will fly on board of the CSES, scheduled to be launched in February 2018. In order to investigate plasma performance of the EFD, the plasma parameters are measured with a Langmuir Probe(LP) and Retarding Potential Analyzers(RPA) in a simulated ionospheric plasma environment. The relevant quantities are obtained as a function of the plasma parameters (i.e. plasma density, electron temperature and ion mass) and system parameters like the orbital velocity, the probe dimensions, the photoelectron current emission and the bias current injected into the probes by the internal constant current source. Here is presented plasma characteristics of the EFD probe. The plasma coupling currents of the EFD probe are calculated analytically. The potential of the EFD probe is measured and calculated analytically.