Tbe experimental characterization of tbe response of FEEP to variations in time of the applied voltage is of the greatest interest in view of the envisaged.appllcatlons of this thruster. In particular, tbe proposed Italian sclentlfac mJsslon GG-FEEP2 features FEEP for drag-free control of a spinning spacecraft. The desJgn of the drag-free controller of GG-FEEP2 requires a detailed knowledge of the dynamical response of FEEP. In particular, the ion emission rise time. i.e. the lag between the application of voltage at the electrodes and the run development of steady state thrust, must be carefully investigated. Likewise, the dependence ohise time upon the voltage step size ls to be evaluated. To thlsend, a dedicated high voltage power supply has been designed and manufactured at Centrospazio. This device ls capable of delivering a pulsed high voltage to the thruster accelerator electrode. in the form of a square wave with a very steep rise and decay. The pulses are in the 0.1 Hz+ 100Hz range, and the pulse duty cycle can be varied between 10% and 90 %. The pulsed power supply has been used to perform a series of tests on 3 em long emitters, covering a wide range of voltage, frequency and duty cycle combinations. The emitters Investigated are sized for the 100 microN thrust range. The main result of the test is that the emission rise and fall time is not in excess of 8 ms at any thrust leveL
Pulsed FEEP: New Experimental Results
MARCUCCIO, SALVO;ANDRENUCCI, MARIANO
1995-01-01
Abstract
Tbe experimental characterization of tbe response of FEEP to variations in time of the applied voltage is of the greatest interest in view of the envisaged.appllcatlons of this thruster. In particular, tbe proposed Italian sclentlfac mJsslon GG-FEEP2 features FEEP for drag-free control of a spinning spacecraft. The desJgn of the drag-free controller of GG-FEEP2 requires a detailed knowledge of the dynamical response of FEEP. In particular, the ion emission rise time. i.e. the lag between the application of voltage at the electrodes and the run development of steady state thrust, must be carefully investigated. Likewise, the dependence ohise time upon the voltage step size ls to be evaluated. To thlsend, a dedicated high voltage power supply has been designed and manufactured at Centrospazio. This device ls capable of delivering a pulsed high voltage to the thruster accelerator electrode. in the form of a square wave with a very steep rise and decay. The pulses are in the 0.1 Hz+ 100Hz range, and the pulse duty cycle can be varied between 10% and 90 %. The pulsed power supply has been used to perform a series of tests on 3 em long emitters, covering a wide range of voltage, frequency and duty cycle combinations. The emitters Investigated are sized for the 100 microN thrust range. The main result of the test is that the emission rise and fall time is not in excess of 8 ms at any thrust leveLI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
