Power Supply

A 150 kJ PFN consisting of 320 capacitors (26 microfd configured in an 80 station L-C ladder is tied to the PHPD facility. This PFN can provide a rectangular current pulse of up to 26 kA for 2 msec or 52 kA for 1 msec. The bank can be easily configured to provide step pulses with two quasi-steady plateaus within each pulse. Risetimes of 25 microsec can be achieved.

Associated Diagnostics

The PHPD facility is traditionally used for detailed probing of thruster chambers and plumes. An electrically controlled probe rack with three translational degrees of freedom and one angular degree of freedom in the horizontal plane is used to position Langmuir and magnetic probes. Spectroscopic diagnostics including a Fabry-Perrot interferometer have also been used in this facility.

Previous Use

The PHPD, being the oldest facility at EPPDyL, has been used for more than 25 years in numerous studies. Recent studies have included mass-injection split, thruster power scaling, discharge asymmetry characterization, anode power deposition and currently anode-region turbulence investigations. The mass injection system has been operated with various propellants including argon, xenon, krypton, helium, hydrogen and deuterium.

Supporting Equipment

A large collection of supporting equipment includes a spectrum analyzer, 5 digital oscilloscopes, small and large-format photographic equipment, a darkroom, 2 video players, CCD cameras, 11 personal computers and LabView implementation.