Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Study of excitation transfer in a flowing helium afterglow pumped with a tuneable dye laser. III. Transfer and quenching reactions of the He$sub 2$(3p $sup 3$Pi) molecule

Journal Article · · J. Chem. Phys., v. 64, no. 6, pp. 2605-2608
OSTI ID:4020127

The collisional transfer of excitation from the He$sub 2$(3p $sup 3$Pi/ subg/) state to other electronically excited states energetically lying within a few KT is examined by optically pumping a flowing helium afterglow with a tuneable dye laser. Rate coefficients for the transfer of excitation to states conserving spin, particularly 3d $sup 3$Pi/subu/ and 3d $sup 3$$delta$/subu/, are found to be greater than 10$sup -10$ cm$sup 3$/sec, resulting in a rapid thermalization of electronic and rotational energy. Relative probabilities of spontaneous radiation for transitions in the visible wavelength range from the product states are found to be 1 and 1/3 for the 3Pi/subu/ and 3$delta$/subu/ states, respectively, relative to that from the initial $sup 3$Pi/subg/ state. The absence of significant fluorescence from singlet states tends to confirm the conservation of spin during such reactions. (AIP)

Research Organization:
University of Texas at Dallas, Richardson, Texas 75080
NSA Number:
NSA-33-031185
OSTI ID:
4020127
Journal Information:
J. Chem. Phys., v. 64, no. 6, pp. 2605-2608, Journal Name: J. Chem. Phys., v. 64, no. 6, pp. 2605-2608; ISSN JCPSA
Country of Publication:
United States
Language:
English