A plasma bridge neutralizer with storage of cæsium as an inert compound has been designed by SEP to operate with a FEEP thruster firing at mN thrust level. When compared to traditional cæsium storage methods, this new concept presents several advantages from the system and operation standpoint. The neutralizer was tested to determine the required electric power and to demonstrate its capability to deliver a mean current of 1 mA for 200 hours. Once these goals were met, the neutralizer was delivered to Centrospazio for carrying out tests on the neutralization of a FEEP ion beam. This work presents preliminary tests performed with the neutralizer alone to check its integration with Centrospazio IV1 space simulator and to assess the reproducibility of performance. The electron emission tests showed that a small anode voltage was needed to get an electron current of 1 mA, even though the anode/target was placed over 100 mm in front of the neutralizer and the keeper discharge was stabilized at low values of keeper current. Furthermore, the results were in almost perfect agreement with those of SEP. Tests were terminated due to contamination of the electric insulators by cæsium vapour. Some methods to eliminate this problem are indicated.
Experimental Investigation of a Plasma Bridge Neutralizer for a mN FEEP Thruster
MARCUCCIO, SALVO;ANDRENUCCI, MARIANO
1994-01-01
Abstract
A plasma bridge neutralizer with storage of cæsium as an inert compound has been designed by SEP to operate with a FEEP thruster firing at mN thrust level. When compared to traditional cæsium storage methods, this new concept presents several advantages from the system and operation standpoint. The neutralizer was tested to determine the required electric power and to demonstrate its capability to deliver a mean current of 1 mA for 200 hours. Once these goals were met, the neutralizer was delivered to Centrospazio for carrying out tests on the neutralization of a FEEP ion beam. This work presents preliminary tests performed with the neutralizer alone to check its integration with Centrospazio IV1 space simulator and to assess the reproducibility of performance. The electron emission tests showed that a small anode voltage was needed to get an electron current of 1 mA, even though the anode/target was placed over 100 mm in front of the neutralizer and the keeper discharge was stabilized at low values of keeper current. Furthermore, the results were in almost perfect agreement with those of SEP. Tests were terminated due to contamination of the electric insulators by cæsium vapour. Some methods to eliminate this problem are indicated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
