Center for Laser Applications

AFOSR Cascade Arc Facility
 

A new cascade arc facility was designed and fabricated at CLA under AFOSR sponsorship to provide a well characterized nonequilibrium plasma which could be used to validate proposed finite rate kinetic models and transport properties. Experimental data were acquired for hydrogen propellants and for ammonia- and hydrazine- equivalent mixtures of hydrogen and nitrogen. Measured experimental profiles of electron number density are generally larger than those predicted from nonequilibrium codes, but the nonequilibrium codes predict the radial distribution of electron number density much better than the equilibrium code. It was found that the finite kinetic rates used at the University of Illinois gave excellent agreement with measured electric fields and gave the best predictions for radial profiles of electron number density.