Observation of Two-Electron Photoionization of the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi mathvariant="normal">H</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math></span> Ion near Threshold

J. B. Donahue; P. A. M. Gram; M. V. Hynes; R. W. Hamm; C. A. Frost; H. C. Bryant; K. B. Butterfield; David A. Clark; W. W. Smith

doi:10.1103/PhysRevLett.48.1538

Observation of Two-Electron Photoionization of the $H^{-}$ Ion near Threshold

J. B. Donahue, P. A. M. Gram, M. V. Hynes, R. W. Hamm, C. A. Frost, H. C. Bryant, K. B. Butterfield, David A. Clark, and W. W. Smith

Phys. Rev. Lett. 48, 1538 – Published 31 May 1982; Erratum Phys. Rev. Lett. 52, 164 (1984)

Abstract

Photoejection of both electrons from the $H^{-}$ ion by a single incident photon has been observed with use of a crossed-relativistic-beam technique. The dipole selection rules for a single photon pick out the ${}^{1}P^{\circ}$ final state. The relative cross section was measured over a 0.30-eV range of photon energies near threshold in steps of 0.007 eV with a resolution of 0.007 eV full width at half maximum. The energy dependence of the cross section in this region was consistent with a Wannier threshold law.