Abstract

The total cross section for excitation of ground state mercury atoms to the 6³P₁ state by 50 eV electrons was experimentally determined to be 0.434 ± 0.04 × 10⁻¹⁶ cm². The apparatus used a pair of single-photon detectors to observe correlated optical photons in the 7 ¹S₀ → 6 ³P₁ → 6 ¹S₀ and 7 ³S₁ → 6 ³P₁ → 6 ¹S₀ cascades. The product of the number of singles counts in the two detectors divided by the number of time-correlated cascade events was used along with angular distribution and correlation factors to determine N, the total number of atoms excited to the 6 ³P₁ state in the interaction region. The correct number N was arrived at in this way without making a separate determination of the overall photon detection efficiency. No standard lamp was needed for calibration nor was reference made to another standard cross section. The apparatus was self-calibrating. The absolute excitation cross section was determined from N and other parameters of the bombardment apparatus.

© 1979 Optical Society of America

Lifetime measurements for excited states of rare-earth atoms using pulse modulation of a cw dye-laser beam

M. Gustavsson, H. Lundberg, L. Nilsson, and S. Svanberg
J. Opt. Soc. Am. 69(7) 984-992 (1979)

Bound, odd-parity J = 1 spectra of the alkaline earths: Ca, Sr, and Ba

J. A. Armstrong, J. J. Wynne, and P. Esherick
J. Opt. Soc. Am. 69(2) 211-230 (1979)

Near-resonance electronic Raman-scattering measurements of Hg(6 ³P₁) in a low-pressure Hg–Ar discharge

Laurence Bigio and David Johnson
J. Opt. Soc. Am. B 8(3) 525-530 (1991)

6 ¹S₀–6 ³P₀ transition in ¹⁹⁹Hg: Determination of the A coefficient and self–pressure broadening

B. L. Wexler, B. E. Wilcomb, and N. Djeu
J. Opt. Soc. Am. 70(7) 863-865 (1980)

Two-photon fluorescence cross-section measurements calibrated with hyper-Rayleigh scattering

Philip Kaatz and David P. Shelton
J. Opt. Soc. Am. B 16(6) 998-1006 (1999)