title: Parity measurements of nuclear levels using a free-electron-laser generated gamma-ray beam.
abstract: The quality and intensity of gamma rays at the High Intensity gamma-ray Source are shown to make nuclear resonance fluorescence studies possible at a new level of precision and efficiency. First experiments have been carried out using an intense (10(7) gamma/s) beam of 100% linearly polarized, nearly monoenergetic, gamma rays on the semimagic nucleus (138)Ba. Negative parity quantum numbers have been assigned to 18 dipole excitations of (138)Ba between 5.5 MeV and 6.5 MeV from azimuthal gamma-intensity asymmetries.
authors.affiliation: A.W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520, USA.
authors.forename: N
authors.initials: N
authors.lastname: Pietralla
authors.forename: Z
authors.initials: Z
authors.lastname: Berant
authors.forename: V N
authors.initials: VN
authors.lastname: Litvinenko
authors.forename: S
authors.initials: S
authors.lastname: Hartman
authors.forename: F F
authors.initials: FF
authors.lastname: Mikhailov
authors.forename: I V
authors.initials: IV
authors.lastname: Pinayev
authors.forename: G
authors.initials: G
authors.lastname: Swift
authors.forename: M W
authors.initials: MW
authors.lastname: Ahmed
authors.forename: J H
authors.initials: JH
authors.lastname: Kelley
authors.forename: S O
authors.initials: SO
authors.lastname: Nelson
authors.forename: R
authors.initials: R
authors.lastname: Prior
authors.forename: K
authors.initials: K
authors.lastname: Sabourov
authors.forename: A P
authors.initials: AP
authors.lastname: Tonchev
authors.forename: H R
authors.initials: HR
authors.lastname: Weller