O. C. Kistner

The g-factors of isomeric states in127, 128Xe

AbstractExcited states in127, 128Xe were populated in the reaction9Be+122Sn atElab=38 MeV. The de-excitation of the isomeric states 7/2+ in127Xe and 8− in128Xe was studied using angular distribution and TDPAD methods on molten122Sn targets. The results are

FIRST MEASUREMENT OF THE REACTION 3HE(GAMMA ,P)X WITH POLARIZED PHOTONS

\begin{gathered} T_{1/2} (7/2^ + ) = 37 \pm 1 ns, g(7/2^ + ) = + 0.241 \pm 0.009 \hfill \\ T_{1/2} (8^ - ) = 83 \pm 2 ns, g(8^ - ) = - 0.036 \pm 0.009. \hfill \\ \end{gathered}

Quadrupole moments of the 12+ isomers in 188Hg and 190Hg

The experimentalg-factors suggest the main configurationsvg7/2 andvh11/2g7/2 for the isomeric states. Detailed analysis of the combined information fromg-factors and transition rates set stringent limits on the admixtures of the wave functions. The quasirotational bands built on the two-quasiparticle 6− and 10+ states are extended to higher spins, (14−) and (16+), respectively, and their structures are analyzed within the framework of the Interacting Boson Model.

Paramagnetic relaxation of Er in an Er single crystal

Abstract The 142Nd(18O, 4n)156Er reaction at 90–95 MeV was used to study 156Er high-spin states to spin 24. In addition to the background ground-state band, two well developed odd-spin side bands, one of each parity, were observed.

First beam-target double-polarization measurements using polarized HD at legs

The first measurement of the reaction He-3(gamma over arrow pointing right, p)X using linearly polarized photons is reported. Cross sections and beam-polarization asymmetries for theta(p)lab = 60-degrees - 100-degrees and E(gamma) - 195-304 MeV are compared with a microscopic calculation which includes one-, two-, and three-nucleon absorption mechanisms. One- and two-nucleon absorption alone fails to describe the data at low proton momenta. The inclusion of three-nucleon absorption significantly improves the comparison with the measured cross sections. However, some features of the asymmetry distributions are not explained.

Polarized Compton scattering from He-4 in the Delta region

The method of perturbed angular distributions was used to measure the temperature dependence of the electric field gradient in Er single crystal for 98 K≤T≤156 K. The Iπ=11− isomer in Er154) was used as a probe. ω0 increases monotonically for 98 K≤T≤259 K and then decreases. A possible cause for this effect may be short range interactions between the f electrons above the Neel point.

Recent Polarization Experiments and the GDH Sum Rule

Abstract The electric quadrupole interaction of the 12+ isomers in 188Hg and 190Hg has been measured in solid Hg. The quadrupole moments deduced, |Q{ 188 Hg (12 + )}| = 91(11) e fm 2 and |Q{ 190 Hg (12 + )}| = 117(14) e fm 2 suggest a possible change in γ-deformation due to the rotation alignment of the i 13 2 quasi-neutrons. The temperature dependence of the electric field gradient tensor in Hg was also determined.

First pion photoproduction double-polarization results with polarized (H)over-right-arrow(D)over-right-arrow at LEGS

The paramagnetic relaxation of Er in an Er single crystal was measured atT≫TN and compared to the relaxation of Er ions in a polycrystalline Pb host. The results indicate an enhancement of at most 50% of the f-conduction electron exchange interaction in Er, as expected for highly ionic f-orbitals. The ratio of the quadrupole moments of the154Er(Iπ=11−) and the155Er(Iπ=13/2+) isomers was measured to be 1.18(3) indicating onset of nuclear deformation at N=87.