The paper deals with the characterization test of a multichannel hollow cathode performed at Alta. The cathode operated at currents from 20 to 150 A, mass °ow rates of Ar ranging between 1 and 5 mg/s, reaching a maximum tip temperature measured on the external cathode wall of about 2500 °C. The external wall temperature has been measured by a bi-color video pyrometer mounted on a 1-axis slit to record the temperature pro¯le along the cathode axis. More than 200 ignitions were carried out for a total of 30 accumulated hours of operation. Besides, the post-test destructive analysis gave evidences of the plasma penetration and surface modi¯cation due to the high operative temperature along with the erosion pattern. Data including cathode temperature and electrical characteristics are presented and analyzed and some operative conditions are compared with the results of a simple algebraic model of arc- cathode interaction.
Experimental study of a Multichannel Hollow Cathode for High Power MPD Thrusters
PAGANUCCI, FABRIZIO;ANDRENUCCI, MARIANO;
2011-01-01
Abstract
The paper deals with the characterization test of a multichannel hollow cathode performed at Alta. The cathode operated at currents from 20 to 150 A, mass °ow rates of Ar ranging between 1 and 5 mg/s, reaching a maximum tip temperature measured on the external cathode wall of about 2500 °C. The external wall temperature has been measured by a bi-color video pyrometer mounted on a 1-axis slit to record the temperature pro¯le along the cathode axis. More than 200 ignitions were carried out for a total of 30 accumulated hours of operation. Besides, the post-test destructive analysis gave evidences of the plasma penetration and surface modi¯cation due to the high operative temperature along with the erosion pattern. Data including cathode temperature and electrical characteristics are presented and analyzed and some operative conditions are compared with the results of a simple algebraic model of arc- cathode interaction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
