A supersonic molecular beam apparatus and characteristics of the beams

A pulsed supersonic molecular beam apparatus has been constructed using an automobile fuel injector as the nozzle beam source and a ''flow-through'' detector. The apparatus is separated into three parts and is differentially evacuated by five turbo-molecular pumps with moderate pumping speeds. The flow-through detector, which has a high senistivity and a sufficient time resolution, was used in time-of-flight (TOF) measurements of molecular velocities. For the TOF measurements of the pulsed beams we developed a data acquisition system using two personal computers. The maximum speed ratios and absolute beam intensities of the pulsed beams of He, Ne, Ar, D2, N2, CO2 and C2H2 prepared in the present apparatus are satisfactorily high compared with the values so far published. (author)