PERFORMANCE OF A SOLENOID-DRIVEN PULSED MOLECULAR-BEAM SOURCE

The characteristics of a commonly used pulsed valve for the production of free jets and molecular beams are analyzed in detail. Special attention is paid to the formation of gas pulses providing a quasisteady flow during a certain time interval within the pulse duration, and to the estimation of a scaling parameter (effective diameter) for the description of the flow field. The adequacy of this effective diameter is checked by performing time-of-flight measurements on molecular beams of Ne, N-2, and CH4, and stimulated Raman spectra on free jets of N-2 and CH4. (C) 1995 American Institute of Physics.