Physics & Astronomy ETDs

Publication Date



This dissertation reports the observation of several series of resonances, for which both electrons are in excited states, in the photodetachment cross section of H-. These P doubly-excited states interfere with the continuum in which they are embedded, and appear as dips in the production cross section of excited neutral hydrogen. The experiment was performed by intersecting an 800 MeV H- beam with a (266 nm) laser beam at varying angles; the relativistic Doppler shift then 'tuned' the photon energy in the barycentric frame. The process was observed by using a magnet strong enough to strip the electrons from the excited hydrogen atoms in selected states n and detecting the resulting protons, which allowed the isolation of the individual n channels. Three resonances are clearly visible in each channel. The data support recent theoretical calculations for the positions of doubly excited 'P resonances, and verify a new Rydberg-like formula for the modified Coulomb potential.

Degree Name


Level of Degree


Department Name

Physics & Astronomy

First Committee Member (Chair)

Donahue, Joey

Second Committee Member

Finley, J. Daniel III

Third Committee Member

McNeil, Bob

Fourth Committee Member

Bassalleck, Bernd

Project Sponsors

This work was supported by the Division of Chemical Sciences, Office of Basic Energy Sciences, Ofice of Energy Research, U.S. Department of Energy, and was also funded in part by the U.S. Army Strategic Defense Command.




Electron nuclear double resonance, Hydrogen ions.

Document Type