Search

From detailed spectroscopy of Cd-110 and Cd-112 following the beta(+)/EC decay of In-110,In-112 and the beta(-) decay of Ag-112, the presence of very weak decay branches from nonyrast states is revealed. In Cd-112, 2(5)(+) -> 0(4)(+) and 4(6)(+) -> 2(5)(+) transitions are observed that yield B(E2; 2(5)(+) -> 0(4)(+)) = 34 +/- 15 W.u. and B(E2; 4(6)(+) -> 2(5)(+)) = 77 +/- 30 W.u., respectively, clearly indicating a collective structure. In 110Cd, a weak decay branch from the 4(6)(+) level to the 2(5)(+) level is observed, and from a lifetime measurement following the (n, n gamma' reaction, B(E2; 4(6)(+) -> 2(5)(+)) = 55 +/- 14 W.u. is determined. A new branch is also observed for the decay of the 6(4)(+) level to the 4(6)(+) state, indicating that the sequence 2(5)(+), 4(6)(+), and 6(4)(+) forms part of a collective structure. The presence of 3(3)(+) and 5(2)(+) levels spaced between the previous sequence is highly suggestive of a gamma band built on the 0(2)(+) shape-coexisting intruder state. The 0(4)(+) levels in Cd-110,Cd-112,Cd-114 have preferred decays to the lowest 2(+) members of the intruder bands, and for 114Cd a previous measurement had established an enhanced B(E2; 0(4)(+) -> 2(3)(+)). The energy systematics of the 0(2)(+), 0(3)(+), and 0(4)(+) levels all display the characteristic parabolic-shaped pattern, suggesting that they are built on multiparticle-multihole proton excitations. The results are compared with beyond-mean-field calculations that reproduce qualitatively the observed levels and their decays and suggest that the 0(1)(+), 0(2)(+), 0(3)(+), and 0(4)(+) levels and the excited states built on them possess different deformations.

From detailed spectroscopy of Cd-110 and Cd-112 following the beta(+)/EC decay of In-110,In-112 and the beta(-) decay of Ag-112, the presence of very weak decay branches from nonyrast states is revealed. In Cd-112, 2(5)(+) -> 0(4)(+) and 4(6)(+) -> 2(5)(+) transitions are observed that yield B(E2; 2(5)(+) -> 0(4)(+)) = 34 +/- 15 W.u. and B(E2; 4(6)(+) -> 2(5)(+)) = 77 +/- 30 W.u., respectively, clearly indicating a collective structure. In 110Cd, a weak decay branch from the 4(6)(+) level to the 2(5)(+) level is observed, and from a lifetime measurement following the (n, n gamma' reaction, B(E2; 4(6)(+) -> 2(5)(+)) = 55 +/- 14 W.u. is determined. A new branch is also observed for the decay of the 6(4)(+) level to the 4(6)(+) state, indicating that the sequence 2(5)(+), 4(6)(+), and 6(4)(+) forms part of a collective structure. The presence of 3(3)(+) and 5(2)(+) levels spaced between the previous sequence is highly suggestive of a gamma band built on the 0(2)(+) shape-coexisting intruder state. The 0(4)(+) levels in Cd-110,Cd-112,Cd-114 have preferred decays to the lowest 2(+) members of the intruder bands, and for 114Cd a previous measurement had established an enhanced B(E2; 0(4)(+) -> 2(3)(+)). The energy systematics of the 0(2)(+), 0(3)(+), and 0(4)(+) levels all display the characteristic parabolic-shaped pattern, suggesting that they are built on multiparticle-multihole proton excitations. The results are compared with beyond-mean-field calculations that reproduce qualitatively the observed levels and their decays and suggest that the 0(1)(+), 0(2)(+), 0(3)(+), and 0(4)(+) levels and the excited states built on them possess different deformations.

From detailed spectroscopy of Cd-110 and Cd-112 following the beta(+)/electron-capture decay of In-110,In-112 and the beta(-) decay of Ag-112, very weak decay branches from nonyrast states are observed. The transition rates determined from the measured branching ratios and level lifetimes obtained with the Doppler-shift attenuation method following inelastic neutron scattering reveal collective enhancements that are suggestive of a series of rotational bands. In Cd-110, a gamma band built on the shape-coexisting intruder configuration is suggested. For Cd-112, the 2(+) and 3(+) intruder gamma-band members are suggested, the 0(3)(+) band is extended to spin 4(+), and the 0(4)(+) band is identified. The results are interpreted using beyond-mean-field calculations employing the symmetry conserving configuration mixing method with the Gogny D1S energy density functional and with the suggestion that the Cd isotopes exhibit multiple shape coexistence.

From detailed spectroscopy of Cd-110 and Cd-112 following the beta(+)/electron-capture decay of In-110,In-112 and the beta(-) decay of Ag-112, very weak decay branches from nonyrast states are observed. The transition rates determined from the measured branching ratios and level lifetimes obtained with the Doppler-shift attenuation method following inelastic neutron scattering reveal collective enhancements that are suggestive of a series of rotational bands. In Cd-110, a gamma band built on the shape-coexisting intruder configuration is suggested. For Cd-112, the 2(+) and 3(+) intruder gamma-band members are suggested, the 0(3)(+) band is extended to spin 4(+), and the 0(4)(+) band is identified. The results are interpreted using beyond-mean-field calculations employing the symmetry conserving configuration mixing method with the Gogny D1S energy density functional and with the suggestion that the Cd isotopes exhibit multiple shape coexistence.

A study of the beta(+)-electron capture decay of In-110 into levels of Cd-110 is combined with a reanalysis of data from a previous study of Cd-110 with the (n, n'gamma) reaction with monoenergetic neutrons. The gamma gamma coincidences from the In-110 decay leads to many new assignments of gamma rays observed in the (n, n'gamma) reaction, permitting the observation of weak low-energy transitions, and setting stringent upper limits on unobserved decay branches. The uncertainties on many of the lifetimes from the (n, n'gamma) reaction are significantly reduced, and limits are established for the lifetimes of levels too long for a direct measurement. The absence of enhanced transitions between the previously assigned phonon states and the deformed intruder states strongly suggests that mixing between the configurations is generally weak, refuting the strong-mixing scenario as an explanation of the decay pattern of the excited 0(+) states in Cd-110. The decay pattern of the nonintruder states is suggestive of a gamma-soft rotor, or O(6) nucleus, rather than a vibrational, or U(5), pattern. The existence of a four-particle-six-hole proton excitation in Cd-110 is also suggested.

A study of the beta(+)-electron capture decay of In-110 into levels of Cd-110 is combined with a reanalysis of data from a previous study of Cd-110 with the (n, n'gamma) reaction with monoenergetic neutrons. The gamma gamma coincidences from the In-110 decay leads to many new assignments of gamma rays observed in the (n, n'gamma) reaction, permitting the observation of weak low-energy transitions, and setting stringent upper limits on unobserved decay branches. The uncertainties on many of the lifetimes from the (n, n'gamma) reaction are significantly reduced, and limits are established for the lifetimes of levels too long for a direct measurement. The absence of enhanced transitions between the previously assigned phonon states and the deformed intruder states strongly suggests that mixing between the configurations is generally weak, refuting the strong-mixing scenario as an explanation of the decay pattern of the excited 0(+) states in Cd-110. The decay pattern of the nonintruder states is suggestive of a gamma-soft rotor, or O(6) nucleus, rather than a vibrational, or U(5), pattern. The existence of a four-particle-six-hole proton excitation in Cd-110 is also suggested.

The (He-3, d) single-proton stripping reaction has been performed on targets of Re-185,Re-187 to investigate the structures of the 4(3)(+) states in Os-186,Os-188. The experiment employed 30 MeV He-3 beams, and the reaction products were analyzed with a Q3D spectrograph. Absolute cross sections were determined at nine angles between 5 degrees and 50 degrees for states up to approximately 3 MeV in excitation energy. Large 5/2(+)[402](pi) + 3/2(+)[402](pi) two-quasiparticle components are deduced for the 4(3)(+) levels of both isotopes. Their magnitudes are in agreement with calculations performed using the quasiparticle phonon model, which predicts a coexistence of a large hexadecapole with a smaller, but sizable, gamma-gamma component in the 4(3)(+).

The (He-3, d) single-proton stripping reaction has been performed on targets of Re-185,Re-187 to investigate the structures of the 4(3)(+) states in Os-186,Os-188. The experiment employed 30 MeV He-3 beams, and the reaction products were analyzed with a Q3D spectrograph. Absolute cross sections were determined at nine angles between 5 degrees and 50 degrees for states up to approximately 3 MeV in excitation energy. Large 5/2(+)[402](pi) + 3/2(+)[402](pi) two-quasiparticle components are deduced for the 4(3)(+) levels of both isotopes. Their magnitudes are in agreement with calculations performed using the quasiparticle phonon model, which predicts a coexistence of a large hexadecapole with a smaller, but sizable, gamma-gamma component in the 4(3)(+).

Military Operations in Urban Terrain present challenges that differ from those of conventional warfare. Often these arise because only limited force can be applied. To compensate, precise information about an opponent's location and condition is desired. This experiment demonstrates the value of such information when an occupied building is approached by coordinated Blue force, but calls into question its utility once inside., Original contains color plates: All DTIC reproductions will be in black and white.

Lifetimes of levels below 4 MeV in ¹¹²Cd have been measured using the Doppler shift attenuation technique following inelastic scattering of monoenergetic neutrons. Reduced transition rates are determined using the results of previous studies and the current lifetimes. The electromagnetic properties of ¹¹²Cd are outlined, and together with results from previous nucleon-transfer studies and inelastic scattering, the levels in ¹¹²Cd are interpreted in terms of single-particle configurations and collective excitations, assuming a vibrational model with intruder states. The collective states and their Γ-ray decays are compared with IBM-2 model calculations that allow for the mixing between the normal phonon states and intruder configurations. Levels below 1.5 MeV are reproduced reasonably well, whereas at higher excitation energy the calculations fail to reproduce the data in detail.