We present here first results on the coincident detection of 0° electrons with Balmer α photons produced in H-/rare gas (Ar and Ne) collisions at 5 keV. One of the goals was to observe possible excitation and decay of H- shape resonances lying above the H(n = 3) threshold that have been predicted recently. It is still not possible to confirm the presence or not of such resonances, however the obtained electron spectrum has a pronounced cusp shape. A cusp in these collisions can only be produced by dipolar interaction between the detached electron and the H(n = 3) atom due to the permanent electric dipole momentum induced by linear Stark effect in the excited hydrogen atom by the field of the slow outgoing electron. In a previous experiment for H(n = 2) we have observed the dipolar cusp, but in this case it is strongly affected by the presence of the 1P° shape resonance lying above the H(n = 2) threshold by 20 meV. At the H(n = 3) threshold the resonant channel seems to have negligible contribution to the electron spectrum, therefore the dipolar cusp appears clearly.
|Number of pages||6|
|Journal||Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms|
|Publication status||Published - Jun 3 1999|
|Event||Proceedings of the 1998 7th Workshop on Fast Ion-Atom Collisions - Debrecen, Hung|
Duration: Sep 9 1998 → Sep 11 1998
ASJC Scopus subject areas
- Nuclear and High Energy Physics