A PULSED SUPERSONIC MOLECULAR-BEAM WITH HIGH ROTATIONAL TEMPERATURES

The construction and operation of a novel high temperature pulsed quartz nozzle employed for the generation of rotationally excited supersonic molecular beams are reported herein. At high stagnation pressures (> 1 bar) the NO molecules in the beam pulse exhibit a translational and rotational behavior identical to heated continuous nozzles (T-rot < 50 K; E(kin) approximate to 7/2 kT(N)). At reduced stagnation pressures (10 mbar-1 bar) the rotational temperatures of the beam molecules are increased substantially (up to T-rot approximate to 700 K) accompanied by a translational behavior, which can be characterized by a small Mach number. The design has produced the rotationally hottest supersonic beam ever prepared in the pulsed mode.