Wang Lie-Lin

Proposed Chiral Doublet Bands in 98Tc

High spin states in odd-odd98 Tc nuclei are studied by in-beam γ-ray spectroscopy with the 96Zr(6Li, 4n) fusion-evaporation reaction at a beam energy of 35 MeV. The previous level scheme is updated. A band based on 1090.7 keV is expanded, and another band based on 1920.6 keV is newly identified. The observed two negative parity bands in 98Tc are proposed to be a pair of chiral doublet bands with the configuration πg9/2 ⊗ νh11/2. The evidence supporting the assignment of the chiral doublet bands is discussed. Signature splitting and signature inversion are observed in the πg9/2 ⊗ νh11/2 band in 98Tc.

Lifetime measurements in chiral nucleus 130Cs

The level lifetimes in partner bands of 130Cs have been measured using the Doppler Shift Attenuation method. The high-spin states of 130Cs were populated via fusion evaporation reaction 124Sn(11B,5n)130Cs at a beam energy of 65 MeV. The absolute M1 and E2 transition probabilities have been deduced. The results indicate that the partner bands of 130Cs manifest the chiral properties.

Quest for Chirality in 107 Ag

High spin states in 107Ag have been studied via the 100Mo(11B, 4n)107Ag reaction at a beam energy of 60 MeV on the HI-13 tandem accelerator at the China Institute of Atomic Energy. By analyzing the gamma-gamma coincidence and their DCO ratios, a new level scheme of 107Ag is presented. The structures for the newly constructed bands are briefly discussed and tentatively assigned to be chiral doublet bands.

New band structures in 107Ag

High spin states in 107Ag are studied via the 100Mo(11B, 4n)107 Ag reaction at an incident beam energy of 60 MeV. Prompt γ-γ coincidence and DCO ratios are measured by the detector arrays in CIAE. The level scheme has been updated and a new negative band belonging to 107Ag is identified. The new negative side band has been constructed and its configuration is tentatively assigned to πg9/2 ⊗ νh11/2(g7/2/d5/2).

Clarification of Confusion in Level Scheme of 124Cs

Low-lying and high-spin states of 124Cs are studied through the 116 Sn(11 B,3n)124 Cs reaction at a beam energy of 45 MeV. Several new linking transitions are observed, including three transitions between the yrast and πh11/2 ⊗ νd3/2 bands and two transitions between the yrast and πh11/2 ⊗ ν(d5/2, g7/2) bands. These transitions fix the excitation energy of the yrast band and its decay path, and confirm the existence of eight E1 linking transitions between the yrast and πh11/2 ⊗ ν(d5/2, g7/2) bands observed before. These E1 linking transitions infer the octupole correlation in Cs. The decay paths of the yrast band are investigated, and discrepancies in the level scheme of 124Cs in the latest two studies are clarified. The reason for the discrepancies is discussed. A new decoupled band is established and temporarily assigned as the unfavored signature partner of πh11/2 ⊗ νd3/2 configuration.

High-spin states in 128I

The high-spin states in 128I have been studied by using in-beam γ-ray spectroscopy with the 124Sn(7Li,3n)128I reaction at beam energies of 25, 28 and 42 MeV. A new level scheme including 20 new levels and 27 new γ-transitions for 128I has been established preliminarily.

Test of Chirality in Nucleus 130Cs

The level lifetimes in partner bands of 130Cs have been measured using the Doppler Shift Attenuation method (DSAM). The high-spin states of 130Cs were populated via fusion evaporation reaction 124Sn(11B; 5n)130Cs at a beam energy of 65 MeV. The absolute M1 and E2 transition probabilities have been deduced. The results indicate that the partner bands of 130Cs indeed manifest chiral properties.

Lifetimes of High Spin States in an Odd-Proton Nucleus 129Cs

Lifetimes of high spin states in 129Cs are measured using the Doppler shift attenuation method. The high spin states of 129Cs are populated following the fusion evaporation reaction 124Sn(11B, 6n)129Cs at a beam energy of 65 MeV. The reduced transition probabilities B(E2) and the transition quadrupole moments Qt in the negative- and positive-parity bands are deduced. The experimental results indicate that the Qt values of the negative parity band are smaller than those of the positive parity bands, probably due to different ?-deformation driving effects of different proton orbitals. The Qt values exhibit a considerable increase near the band crossing region in these bands. This behavior demonstrates that nuclear shape changing results from the neutron or proton alignments. The signature splitting of the ?h11/2 and ?g7/2 bands shows the opposite changing trend after backbending due to the h11/2 neutron and h11/2 proton alignments, respectively.

Structural evolution of the intruder band in 118 Sn

Excited states of the positive-parity intruder band in 118Sn have been studied via the 116Cd(7Li, 1p4n) reaction at 7Li energy of 48 MeV using techniques of in-beam γ-ray spectroscopy. This intruder band has been observed up to 7187 keV with spin (16+). The structural evolution of this intruder band with increasing angular momentum has been discussed in terms of the aligned angular momentum and the ratio of the E-Gamma Over Spin (E-GOS) curve.

High-Spin States in 141Pm

The high-spin states of 141Pm nucleus have been studied by using in-beam γ-ray spectroscopy technology through the126Te(19F, 4n) reaction at a beam energy of 90 MeV. The previous level scheme has been extended with spin up to 49/2 ℏ. Many new levels and transitions are identified. Five collective band structures are observed. Based on systematic comparison with the neighboring nuclei, two bands with strong ΔI = 1 M1 transitions inside the bands are proposed as the oblate bands with γ~−60°, and three bands with large signature splitting have been suggested as the oblate-triaxial deformation with γ~−90°. The characteristics for these bands have been discussed.