Double Excitations of Helium in Weak Static Electric Fields
2006 (English)In: Physical Review Letters, ISSN 0031-9007, Vol. 96, 043002- p.Article in journal (Refereed) Published
A dramatic electric field dependence has been observed in the fluorescence yield spectrum of the doubly excited states in helium, where a rich phenomenology is encountered below the N=2 threshold. Fluorescence yields of certain states can be tuned to zero, while other dipole-forbidden states are significantly enhanced, for fields much weaker than 1 kV/cm. Using an R-matrix multichannel quantum defect theory, spherical-to-parabolic frame transformation method, we are able to reproduce the main features of the observed spectrum, and we discuss the qualitative behavior in terms of weak electric field mixing.
Place, publisher, year, edition, pages
2006. Vol. 96, 043002- p.
IdentifiersURN: urn:nbn:se:uu:diva-94517DOI: 10.1103/PhysRevLett.96.043002OAI: oai:DiVA.org:uu-94517DiVA: diva2:168390