INSTRUMENTATION FOR TIME-RESOLVED ELECTRON-DIFFRACTION SPANNING THE TIME-DOMAIN FROM MICROSECONDS TO PICOSECONDS

Recent instrumental improvements which successfully extend the time re solution of pulsed beam electron diffraction to the picosecond regime are described. Based on modifications of an existing nanosecond appara tus, a;new sample inlet system, electron pulse generation laser, and a mplified detector have been incorporated into the design such that sig nificant improvements in both the signal level and ultimate time resol ution are achieved; an upper estimate of the electron pulse width is s imilar to 20 ps. Enhancements are such that, for operation in the nano second time domain, an entire diffraction pattern over a useful range of scattering angles may be collected from a gas-phase sample in a sin gle electron pulse. (C) 1998 American Institute of Physics. [S0034-674 8(98)01707-9]