SUPRATHERMAL ELECTRONS OBSERVED ON THE TSS-1R SATELLITE

Particle measurements up to 27,000 eV were made on the TSS-IR (Tethere d Satellite System) satellite. The TSS satellite developed a positive bias due to the Lorentz force. It was the intent that electron measure ments on the TSS satellite could be used to track the spacecraft poten tial and collected current, What was observed was quite different, Acc elerated ionospheric electrons were observed to only similar to 70 eV even though larger spacecraft potentials were observed by other diagno stics on the TSS satellite. When observed they agreed with these indep endent measurements of the potential. In addition to the anticipated a ccelerated thermals, a suprathermal population of electrons was observ ed to be centered around 200 eV. This population exhibited a 4 orders- of-magnitude increase in intensity as the spacecraft potential exceede d the O+ ram energy. The disappearance of the accelerated thermals is explained by the observation that the suprathermal flux becomes larger in magnitude, thus hiding the thermals. However the suprathermals can not be the dominant current carriers if they are the result of a DC pr ocess as their calculated current magnitude exceeds that observed. The se results are best explained if one assumes an AC acceleration of the suprathermal electrons whose free energy is derived from the differen tial ((E) over right arrow x (E) over right arrow driven) drift betwee n electrons and ions.