title: Photoassociation spectroscopy of cold he(2 ^{3}s) atoms.
abstract: We observe vibrational states by photoassociation spectroscopy of cold He(2 ^{3}S) atoms. Photoassociation resonances are detected as peaks in the Penning ionization rate over a frequency range of 20 GHz below the atomic 2 ^{3}S_{1}-2 ^{3}P_{2} transition frequency. We have observed three vibrational series, of which two can be identified. A possible mechanism to explain the observed increase of the Penning ionization rate is discussed.
authors.affiliation: Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Herschbach
authors.forename: P J
authors.initials: PJ
authors.lastname: Tol
authors.forename: W
authors.initials: W
authors.lastname: Vassen
authors.forename: W
authors.initials: W
authors.lastname: Hogervorst
authors.forename: G
authors.initials: G
authors.lastname: Woestenenk
authors.forename: J W
authors.initials: JW
authors.lastname: Thomsen
authors.forename: P
authors.initials: P
authors.lastname: van der Straten
authors.forename: A
authors.initials: A
authors.lastname: Niehaus