The levels in neutron-rich odd-A ^(107,109)Ru nuclei have been investigated by using γ -γ -and γ -γ -γ-coincidence studies of the prompt γ-rays from the spontaneous fission of 252Cf. The ground state bands and t...The levels in neutron-rich odd-A ^(107,109)Ru nuclei have been investigated by using γ -γ -and γ -γ -γ-coincidence studies of the prompt γ-rays from the spontaneous fission of 252Cf. The ground state bands and the negative parity bands are identified and expanded in both nuclei. Triaxial rotor plus particle model calculations indicate the ground state bands originate from v(d_(5/2)+g_(7/2)) quasiparticle configurations and the negative parity bands are from vh_(11/2) orbital.展开更多
The Generalized Collective Model (GCM) is applied to the even even neutron rich 104,106,108 Mo isotopes. With GCM the energy spectra, absolute B(E2) values, some B(E2) branching ratios and Potential Energy ...The Generalized Collective Model (GCM) is applied to the even even neutron rich 104,106,108 Mo isotopes. With GCM the energy spectra, absolute B(E2) values, some B(E2) branching ratios and Potential Energy Surfaces (PES) for the 104,106,108 Mo isotopes are calculated. The PES of all these isotopes show a prolate minimum which becomes more pronounced in 106 Mo. The results are in agreement with the recent experimental report but are different from the viewpoint of the triaxial rotors, or γ soft deformation. Through a systematic study of PES, it is suggested that the even even neutron rich 104,106,108 Mo isotopes have prolate deformation.展开更多
High spin states in 138Ce have been investigated following heavy-ion induced reactions carried out at the China Institute of Atomic Energy,Beijing.Two collective rotational bands were established for the first time.Th...High spin states in 138Ce have been investigated following heavy-ion induced reactions carried out at the China Institute of Atomic Energy,Beijing.Two collective rotational bands were established for the first time.These two bands show oblate deformation withγ=-60°and probably originate from the four quasiparticle configurationsπg7/2πh11/2Uvh11/2 vd3/2 andπg7/2Uπh11/2[vh11/2]2,respectively.These oblate bands exhibit strong M1 transitions,no signature splitting and different moments of inertia from those of prolate bands.展开更多
Levels in the neutron-rich ^(104)Mo nucleus have been investigated by observing promptγ-rays from the spontaneous fission of 252Cf with the Gammasphere detector array.The ground-state band,the one-phonon and the two-...Levels in the neutron-rich ^(104)Mo nucleus have been investigated by observing promptγ-rays from the spontaneous fission of 252Cf with the Gammasphere detector array.The ground-state band,the one-phonon and the two-phononγ-vibrational bands as well as a quasiparticle band have been confirmed and expanded with spin up to 14ħ.Other two side bands probably built on new quasiparticle states are identified.The possible configurations for the quasiparticle bands are discussed.Two of the quasiparticle bands show larger moments of inertia and may have pair-free characteristics.The levels of the ground-state band,the one-phononγ-band and the two-phononγ-band calculated from a general collective model are in close agreement with the experimental data.展开更多
Octupole deformation bands built onπh ll/2 orbital in neutron-rich odd-Z 145,147La nuclei have been investigated by measuring the promptγ-rays emitted from the 252Cf source.The alternating parity band structures and...Octupole deformation bands built onπh ll/2 orbital in neutron-rich odd-Z 145,147La nuclei have been investigated by measuring the promptγ-rays emitted from the 252Cf source.The alternating parity band structures and strong E1 transitions observed between negative-and positive-parity bands in both nuclei indicate the octupole deformation enhanced by the h ll/2 single proton coupling.According to observed energy displacements the octupole deformation becomes stable at the intermediate spin states.展开更多
High-spin states in ^(122)Ba have been investigated in the ^(107)Ag(^(19)F,4n)reaction by in-beamγ-ray spectroscopic methods.The ground-state band has been observed with spin up to 20ħand a negative-parity band is id...High-spin states in ^(122)Ba have been investigated in the ^(107)Ag(^(19)F,4n)reaction by in-beamγ-ray spectroscopic methods.The ground-state band has been observed with spin up to 20ħand a negative-parity band is identified with spin state up to 19ħ.A band-crossing in the yrast band is observed at a rotational frequency of ħω≈0.36 MeV and,in accordance with cranked shell model calculations,is interpreted as arising from the alignment of two h_(11/2) protons.Strong E1 transitions between the negative-parity and the yrast bands have been observed,which are proposed as possible evidence for octupole correlations.展开更多
High spin states in ^(137) Ce have been studied by using the heavy-ion induced reaction ^(124)Sn(^(18) O, 5n) carried out at China Institute of Atomic Energy. Partial level scheme with spin up to (43/2^(-)), including...High spin states in ^(137) Ce have been studied by using the heavy-ion induced reaction ^(124)Sn(^(18) O, 5n) carried out at China Institute of Atomic Energy. Partial level scheme with spin up to (43/2^(-)), including a high spin collective rotational band observed for the first time, has been established. The collective band shows the properties similar to those oblate bands with γ ~-60° in neighboring nuclei and probably originates from the five quasi-particle configuration νs_(1/2)■ [vh_(11/2)]^(2)π9_(7/2)■ πh_(11/2). The characteristics of this oblate band have been discussed.展开更多
High spin states in neutron-rich odd-N ^(145)Ba nucleus have been investigated from study of promptγ-rays in spontaneous fission of^(252)Cf.The alternating parity bands are identified indicating octupole deformation ...High spin states in neutron-rich odd-N ^(145)Ba nucleus have been investigated from study of promptγ-rays in spontaneous fission of^(252)Cf.The alternating parity bands are identified indicating octupole deformation with simplex quantum number s=-i.The ground state band shows signature splitting and inversion at low spin.These collective band structures exhibit the competition and co-existence between symmetric and asymmetric shapes.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.19775026the Science Foundation for Nuclear Industry of China under Grant No.Y7197AY509the U.S.Department of Energy under Grant Nos.DE-FG05-88ER40407 and DE-FG03-87ER40323.
文摘The levels in neutron-rich odd-A ^(107,109)Ru nuclei have been investigated by using γ -γ -and γ -γ -γ-coincidence studies of the prompt γ-rays from the spontaneous fission of 252Cf. The ground state bands and the negative parity bands are identified and expanded in both nuclei. Triaxial rotor plus particle model calculations indicate the ground state bands originate from v(d_(5/2)+g_(7/2)) quasiparticle configurations and the negative parity bands are from vh_(11/2) orbital.
文摘The Generalized Collective Model (GCM) is applied to the even even neutron rich 104,106,108 Mo isotopes. With GCM the energy spectra, absolute B(E2) values, some B(E2) branching ratios and Potential Energy Surfaces (PES) for the 104,106,108 Mo isotopes are calculated. The PES of all these isotopes show a prolate minimum which becomes more pronounced in 106 Mo. The results are in agreement with the recent experimental report but are different from the viewpoint of the triaxial rotors, or γ soft deformation. Through a systematic study of PES, it is suggested that the even even neutron rich 104,106,108 Mo isotopes have prolate deformation.
基金the National Natural Science Foundation of China under Grant No.19775026the Science Foundation for the Nuclear Industry of China under Grant No.Y7192AY509.
文摘High spin states in 138Ce have been investigated following heavy-ion induced reactions carried out at the China Institute of Atomic Energy,Beijing.Two collective rotational bands were established for the first time.These two bands show oblate deformation withγ=-60°and probably originate from the four quasiparticle configurationsπg7/2πh11/2Uvh11/2 vd3/2 andπg7/2Uπh11/2[vh11/2]2,respectively.These oblate bands exhibit strong M1 transitions,no signature splitting and different moments of inertia from those of prolate bands.
基金Supported by the National Natural Science Foundation of China under Grant No.19975028the Science Foundation of China for Nuclear Industry under Grant No.Y7197AY509+1 种基金the Major State Basic Research Development Program of China under Contract No.G2000077400the U.S.Department of Energy under Grant No.DE-FG05-88ER40407.
文摘Levels in the neutron-rich ^(104)Mo nucleus have been investigated by observing promptγ-rays from the spontaneous fission of 252Cf with the Gammasphere detector array.The ground-state band,the one-phonon and the two-phononγ-vibrational bands as well as a quasiparticle band have been confirmed and expanded with spin up to 14ħ.Other two side bands probably built on new quasiparticle states are identified.The possible configurations for the quasiparticle bands are discussed.Two of the quasiparticle bands show larger moments of inertia and may have pair-free characteristics.The levels of the ground-state band,the one-phononγ-band and the two-phononγ-band calculated from a general collective model are in close agreement with the experimental data.
基金Supported by the National Natural Science Foundation of China under Grant No.19775026the Science Foundation for Nuclear Industry of China under Grant No.Y7197AY509the U.S.Department of Energy under Grant Nos.DE-FG05-88ER40407 and DE-FG03-87ER40323.
文摘Octupole deformation bands built onπh ll/2 orbital in neutron-rich odd-Z 145,147La nuclei have been investigated by measuring the promptγ-rays emitted from the 252Cf source.The alternating parity band structures and strong E1 transitions observed between negative-and positive-parity bands in both nuclei indicate the octupole deformation enhanced by the h ll/2 single proton coupling.According to observed energy displacements the octupole deformation becomes stable at the intermediate spin states.
基金Supported by the Major State Basic Research Development Program under Contract No.G2000077400the National Natural Science Foundation under Grant No.19975028the Science Foundation for Nuclear Indus try of China under Grant No.Y7197AY509.
文摘High-spin states in ^(122)Ba have been investigated in the ^(107)Ag(^(19)F,4n)reaction by in-beamγ-ray spectroscopic methods.The ground-state band has been observed with spin up to 20ħand a negative-parity band is identified with spin state up to 19ħ.A band-crossing in the yrast band is observed at a rotational frequency of ħω≈0.36 MeV and,in accordance with cranked shell model calculations,is interpreted as arising from the alignment of two h_(11/2) protons.Strong E1 transitions between the negative-parity and the yrast bands have been observed,which are proposed as possible evidence for octupole correlations.
基金Supported by the National Natural Science Foundation of China under Grant No.19775026the Science Foundation for the Nuclear Industry of China under Grant No.Y7192AY509.
文摘High spin states in ^(137) Ce have been studied by using the heavy-ion induced reaction ^(124)Sn(^(18) O, 5n) carried out at China Institute of Atomic Energy. Partial level scheme with spin up to (43/2^(-)), including a high spin collective rotational band observed for the first time, has been established. The collective band shows the properties similar to those oblate bands with γ ~-60° in neighboring nuclei and probably originates from the five quasi-particle configuration νs_(1/2)■ [vh_(11/2)]^(2)π9_(7/2)■ πh_(11/2). The characteristics of this oblate band have been discussed.
基金Supported by the National Natural Science Foundation of China under Grant No.19775026the Science Foundation for Nuclear Industry of China under Grant No.Y7197AY509the U.S.Department of Energy under Grant Nos.DE-FG05-88ER0407 and DE-FG03-87ER40323.
文摘High spin states in neutron-rich odd-N ^(145)Ba nucleus have been investigated from study of promptγ-rays in spontaneous fission of^(252)Cf.The alternating parity bands are identified indicating octupole deformation with simplex quantum number s=-i.The ground state band shows signature splitting and inversion at low spin.These collective band structures exhibit the competition and co-existence between symmetric and asymmetric shapes.
