Lu Jing-Bin

Structure of the Semi-decoupled 1/2[411] Band in Odd Proton Nucleus169Ta

High spin states of the odd proton-nucleus 169Ta have been populated in the reaction 155Gd(19F,5n) with beam energies of 97 MeV. Rotational band based on d3/2 proton 1/2[411] Nilsson state has been pushed up to 39/2+ in the α = 1/2 decay sequence. Its signature partner, the α = -1/2 decay sequence with four link transitions has been established and 1/2[411] band in 169Ta was reassigned to be a semi-decoupled band. The systematics of the signature splitting in the K = 1/2 bands in the rear-earth region and the accidental degeneracy conclusion given by the angular projection shell model were discussed.

Search for the Chiral Band in the N =71 Odd-Odd Nucleus 126Cs

High-spin states in 126Cs are studied via the 116Cd(14N, 4n) reaction at a beam energy of 65 MeV. The sideband of the πh11/2⊗νh11/2 yrast band, a ΔI = 2 band known from previous study, is developed into a ΔI = 1 coupled structure at low spins. This sideband is assigned to be built on the same configuration as the yrast band according to the measured ratios of directional correlation of orientation and observed alignment properties. On the basis of comparisons with the previously proposed chiral doublet bands for 128,130Cs, the observed two πh11/2⊗νh11/2 bands are proposed to be candidates for chiral doublet bands in 126Cs.

Designing of the 14 MeV neutron moderator for BNCT

In boron neutron capture therapy (BNCT), the ratio of the fast neutron flux to the neutron flux in the tumor (RFNT) must be less than 3%. If a D-T neutron generator is used in BNCT, the 14 MeV neutron moderator must be optimized to reduce the RFNT. Based on the neutron moderation theory and the simulation results, tungsten, lead and diamond were used to moderate the 14 MeV neutrons. Satisfying RFNT of less than 3%, the maximum neutron flux in the tumor was achieved with a three-layer moderator comprised of a 3 cm thick tungsten layer, a 14 cm thick lead layer and a 21 cm thick diamond layer.

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).

Band crossings and signature splitting in 159Ho

High spin states in 159 Ho were populated in the reaction 152 Sm(11 B,4n) at 60 MeV. The rotational band based on the 7/2+ [404] Nilsson configuration has been established and the rotational bands based on the 7/2- [523], 1/2+ [411] and 1/2- [541] Nilsson configurations have been extended. The neutron band crossings of the various bands and the energy signature splitting of the 7/2- [523] bands are analysed in terms of the cranked shell model.

Lifetimes of Excited Levels in131Ce

The fusion–evaporation reaction 116Sn (19F, p3n) 131Ce at projectile energy of 95 MeV is used to populate high spin states in 131Ce. The de-exciting γ-rays are detected in γ–γ coincidence measurement with Compton-suppressed BGO-HPGe detectors. Level lifetimes of 131Ce were determined by using the Doppler shift attenuation method. The experimental results indicate that collectivity of 131Ce is reduced relative to that of 130Ce and it follows that deformation decreases with increase of the neutron number on the basis of systematic comparison of transition quadrupole moments for the light cerium isotopes.

Lifetimes of High Spin Yrast States in Odd-Proton Nucleus131Pr

Lifetimes of the high spin yrast states in the odd-proton-nucleus 131Pr have been determined by analysing the Doppler broadened line shapes for the de-exciting ?-rays following the 116Sn (19F,4n) 131Pr reaction at a bombarding energy of 95?MeV. The transition quadrupole moments extracted from the measured lifetimes exhibit a considerable reduction near the rotational frequency of 0.42?MeV, at which the J(1) and J(2) moments of inertia indicate a band crossing. The experimental result demonstrates occurrence of the nuclear shape change induced by band crossing associated with the alignment of a pair of h11/2 protons.

Robustness of Entanglement During Decoherence

Finding the most robust entangled states during the whole process of decoherence is a particularly fundamental problem for quantum physics and quantum information processing. In this paper, the decoherence process of two-qubit system under two individual identical decoherence channels is investigated systematically. We find that although the robustness of two-qubit states with same initial entanglement is usually different, the Bell-like states are always the most robust entangled states during decoherence. That is to say, affected by the same amount of noise, the remain entanglement of an arbitrary two-qubit state is not more than that of a Bell-like state with the same initial entanglement.

High-Spin States in the Odd-Odd Nucleus 92Nb

High spin states of the odd-odd nucleus 92Nb are investigated using the 82Se (14N, 4n)92Nb reaction at a beam energy of 54 MeV. The level scheme of the 92Nb was extended up to Jπ =(16+) at about 7.3 MeV and Jπ=(21−) at about 9.7 MeV. According to systematic analyses and a comparison with the neighboring nucleus, the higher spin states could be interpreted by the multi-particle excitations in the π(f5/2,p3/2,p1/2,g9/2)⊗ν(p1/2,g9/2,d5/2, g7/2) configuration space.

New high spin level scheme of 87Sr

High spin states of the odd-A 87Sr were populated by the fusion-evaporation reaction 82Se(9Be,4n) 87Sr at a beam energy of 46 MeV. Excited levels of 87Sr have been extended up to an excitation energy of 7.4 MeV at spin 31/2ħ. The coupling of a g9/2 neutron hole to the yrast states of the 88Sr core can account for the low-lying states in 87Sr. The structure of the higher spin states is discussed by analogy with those of the neighboring odd-A N = 49 isotones and possible configurations are proposed.