Laser production of supersonic metal cluster beams

Magnetically compensated supersonic beams for nonlinear optics

Doppler frequently shifts for a laser field interacting with a diverging supersonic atomic beam are canceled using spatially varying Zeeman shifts. Dense atomic beams with long interaction path lengths and narrow linewidths are obtained for spectroscopic and nonlinear-optics applications.

Focal Points in Mass Spectrometry

Mass spectrometry has advanced with the renaissance of time-of-flight mass analysis, the use of ion traps as analyzers and reactors, the application of tandem mass spectrometers to problems in ionic reaction mechanisms and chemical analysis, and the development of new desorption ionization techniques. These developments have allowed determination of the molecular weight distributions for polymers through the 10,000-dalton range, as well as the molecular weight and partial sequence of biopolymers of similar size. Surfaces can be characterized by use of the mass, energy, and angle distributions of particles ejected by sputtering or by laser-induced desorption. Mass spectrometry has yielded new information on the kinetics of catalytic surface reactions and on the reactivity of metal clusters.