Stark broadening of H/sup -/ resonances in large electric fields

Technical Report · Fri Jun 01 04:00:00 EDT 1984

OSTI ID:6529861

Butterfield, K B

Resonances in the H/sup -/ ion near the n=2 energy of H/sup 0/ were studied in very large electric fields. The experiments used the 800 MeV H/sup -/ ion beam at the Clinton P. Anderson Meson Physics Facility (LAMPF) at Los Alamos, New Mexico. Third harmonic photons (3.5 eV) from a Nd:YAG laser were Doppler tuned to produce the 11 eV photons required to excite the resonances. A magnetic field perpendicular to the H/sup -/ velocity appeared via the Lorentz transformation as a very large electric field in the center of mass frame of reference. The magnetic fields were produced by a pulsed power supply driving a Helmholtz coil. The maximum field used (3 MV/cm) was sufficient to field ionize enough of the H/sup -/ beam, within the 1.5 cm high field region, to saturate the detectors. The onset of field ionization was observed to be at 2.5 MV/cm. Surprisingly, the /sup 1/P/sup 0/ shape resonance and /sup 1/D/sup e/ resonance were not quenched by the largest fields used. Cross sections for these resonances were measured at several lesser fields, and widths, centroid energies, and strengths for each resonance were determined. The cross section for producing H/sup 0/ (n=2) was measured for the first time and the Fano function was shown to be inadequate to describe the shape resonance. 108 references, 33 figures, 3 tables.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6529861
• Report Number(s): LA-10149-T; ON: DE84016974
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ANIONS
BEAMS
CHARGED PARTICLES
CROSS SECTIONS
DATA
ELECTRIC FIELDS
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
ENERGY RANGE
EXPERIMENTAL DATA
GROUND STATES
HYDROGEN IONS
HYDROGEN IONS 1 MINUS
INFORMATION
IONS
LASER RADIATION
MEV RANGE
MEV RANGE 100-1000
NUMERICAL DATA
POLARIZED BEAMS
RADIATIONS
RESONANCE
STARK EFFECT