Slit pulsed valve for generation of long-path-length supersonic expansions

Abstract
We describe a valve for production of jet-cooled species in a pulsed, long-path-length (1.2-cm) supersonic expansion. The valve produces 150–600-μs-duration pulses at repetition rates up to 60 Hz from a nozzle with variable slit width, and is suitable for use with corrosive gases and vapors.