Observation of doubly excited resonances in theH−ion

Abstract

Laser photodetachment on a relativistic H beam has revealed several series of resonances in which both electrons are excited. These "bound states in the continuum" appear as dips in the partial production cross sections of various excited states of neutral hydrogen. We present here a detailed account of the experimental observation of the resonances and the results of fits of the measured yields to sets of Fano profiles. A simple analytic formula for the energy-level spacing in this quantum-mechanical three-body system is verified.In this paper we report the observation of several series of high-lying 'P resonances in the photodetachment cross section of H . The energy levels of these doubly excited states are shown to obey a simple and elegant analytic formula. We discuss here in greater depth the results presented earlier. '

Multipole structure in asymmetrical double Rydberg states

“…Electronic correlation studies in highly doubly excited atoms in the different situations schematically described above have been reported previously. These range from the pure three-body Coulomb systems He [4,5] and H [6] to non-Coulombic ones involving electronic collision excitation in He [7,8] and sequential laser excitation of both electrons in alkaline-earth-metal atoms [9 -15]. To overcome the autoionization broadening of the lines, dou- presence of weak I =k+1 components on both sides of the main I =k line, which corresponds to the selected 6snk state.…”

Photodetachment using atom and ion detection

“…Both were members of an A ¼ þ1 series of Feshbach resonances. Later, Harris et al (1990) showed that many A ¼ þ1 resonances of 1 P o symmetry lie below each of the H(n=5-8) thresholds. For example, the window resonances shown in Fig.…”

Reexamination of theHe−1s2p2Walter1, Seifert2, Peterson3 1994Phys. Rev. A510110View full textAdd to dashboardCite

“…If the attraction is not quite strong enough to form a Feshbach resonance, a "shape" resonance can exist above the level of the parent state if the additional electron's orbital angular momentum I is greater than or equal to 1 shape resonances exist. Their technique was further applied at even higher energies to explore several resonance phenomena including doubly excited states [8,9].…”