Response of the /sup 1/P/sup o/ resonance near n = 3 in the H/sup -/ continuum to external electric fields

Journal Article · Sun Nov 15 04:00:00 EST 1987 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.36.4728· OSTI ID:6062420

Cohen, S; Bryant, H C; Harvey, C J; Stewart, J E; Butterfield, K B; Clark, D A; Donahue, J B; MacArthur, D W; Comtet, G; Smith, W W; others, and

The response to external electric fields of the /sup 1/P/sup o/ resonance ''dip'' in the H/sup -/ photodetachment continuum cross section below the n = 3 hydrogenic excitation threshold is investigated. Using the relativistic (..beta.. = 0.806) 650-MeV H/sup -/ beam at the Clinton P. Anderson Meson Physics Facility (LAMPF) in Los Alamos, the fourth harmonic (266 nm) of a Nd:YAG laser (where YAG denotes yttrium aluminum garnet) is Doppler shifted to provide a continuously tunable photon beam in the rest frame of the ions. The magnetic field from pulsed Helmholtz coils, surrounding the photon-H/sup -/ interaction point provides a Lorentz-transformed barycentric electric field. As the magnitude of the external field is increased, there is no observed shift in the photon energy to excite the resonance E/sub o/, 12.650 +- 0.001 eV, until quenching occurs at a field strength of 2.36 MV/cm. The effective strength of the resonant state is consistent with a linear decrease with increasing field. The line shape index q is constant within statistical uncertainty, until the resonance disappears. There is evidence that the width of the resonance remains constant at fields below 1.25 MV/cm. It then broadens at higher fields before the resonance quenches.

• Research Organization: Drexel University, Philadelphia, Pennsylvania 19104
• OSTI ID: 6062420
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 36:10; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ANIONS
CHARGED PARTICLES
COLLISIONS
ELECTRIC FIELDS
ELECTRON DETACHMENT
ENERGY
ENERGY LEVELS
ENERGY RANGE
HYDROGEN IONS
HYDROGEN IONS 1 MINUS
IONS
LEVEL WIDTHS
PHOTON COLLISIONS
RELATIVISTIC RANGE
RESONANCE
THRESHOLD ENERGY