Pulsed Proton-beam Absorption Spectrum of Helium Gas at 4.2 K and Liquid at 2.6 K

Session FP - Poster Session III.
POSTER session, Friday afternoon, May 17
Atrium, Chemistry Building

[FP.39] Pulsed Proton-beam Absorption Spectrum of Helium Gas at 4.2 K and Liquid at 2.6 K

Rosario G. Lamonica, Robert L. Brooks, James L. Hunt (\mbox<\!GWP\!>^2 and Department of Physics, University of Guelph)

Pulsed proton-beam absorption spectroscopy, previously restricted to the infrared spectral region, has been extended to the visible and near infrared by the use of a silicon-avalanche photodiode (Si-APD) detector. The strongest absorption has been the c\,^3\Sigma _g^+\leftarrow a\,^3 \Sigma _u^+ with a number of different vibrational levels taking part in the liquid. Not nearly so many vibrational levels are observed for the gas transitions but rotational structure for the (0-0) transition has been well resolved. The signal-to-noise of the absorption spectrum in the liquid is markedly improved over that of previous workers, and a re-examination of the transition assignments will be presented.

Part F of program listing