title: One photon two electron excitations between doubly excited states of helium.
abstract: Variational calculations using Hylleraas coordinates have been performed for the first time for estimating the energies of 3dnf((1,3)D(o)) state of helium for n=4,5,6. We predict absorption peaks at 12.219, 12.647, and 12.857 eV for the (3)D(o) series converging to N=3 ionization threshold of He(+) which can be expected to be observed in the experiment of single photon double excitation of lowest (3)P(e) state of helium placed in synchrotron radiation.
authors.affiliation: Kandi Raj College, Kandi, Murshidabad, West Bengal 742 137, India.
authors.forename: S
authors.initials: S
authors.lastname: Bhattacharyya
authors.forename: A N
authors.initials: AN
authors.lastname: Sil
authors.forename: T K
authors.initials: TK
authors.lastname: Mukherjee
authors.forename: P K
authors.initials: PK
authors.lastname: Mukherjee