The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution met...The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution method and calculated by a cranking shell model.A peak structure of the g-factors has been observed for the first time.The measured g-factors confirm the mixed configuration of proton and neutron alignments.展开更多
High spin states of the odd-proton nucleus ^(167)Lu have been studied via ^(152)Sm(^(19)F,4n)^(167)Lu reaction at 87MeV beam energy.A weakly populated new rotationa1 band has been observed and assigned as i13/2 proton...High spin states of the odd-proton nucleus ^(167)Lu have been studied via ^(152)Sm(^(19)F,4n)^(167)Lu reaction at 87MeV beam energy.A weakly populated new rotationa1 band has been observed and assigned as i13/2 proton 1/2^(+)[660] band.This new band and the 1/2^(+)[660] band in ^(171)Ta from the early work are classified as superdeformed bands with triaxiality.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^(84)Rb have been studied by using the^(70)Zn(^(18)O,p3n)^(84)Rb reaction at a beam energy of 75 MeV.Theγ-γcoincidence,excitation function and ratios for directional correlation of oriented states...High-spin states in^(84)Rb have been studied by using the^(70)Zn(^(18)O,p3n)^(84)Rb reaction at a beam energy of 75 MeV.Theγ-γcoincidence,excitation function and ratios for directional correlation of oriented states were performed.A new level scheme was established in which the positive and negative parity bands have been extended up to 17^(+)and 17^(-)with excitation energy about 7MeV.The signature splitting and signature inversion of the positive parity yrast bands were observed and are discussed.展开更多
Structure of high spin states in ^(87)Zr was studied through the reaction ^(59)Co(^(32)S,3pn)^(87)Zr at a beam energy of 118 MeV using in-beam γ-ray spectroscopic method.Measurement of γ-γ coincidence was performed...Structure of high spin states in ^(87)Zr was studied through the reaction ^(59)Co(^(32)S,3pn)^(87)Zr at a beam energy of 118 MeV using in-beam γ-ray spectroscopic method.Measurement of γ-γ coincidence was performed,and directional correlation orientation ratios of someγrays were determined.The level scheme of ^(87)Zr was established up to spin(37/2^(+))and(43/2^(-)).Many previously unknown states have been observed.Comparison with neighboring isotones indicates that the effect of neutron on nuclear structure property is predominant compared to proton,and there is a tendency of reduction in band crossing frequency with increasing proton number.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
High-spin states in the odd-proton nucleus^(135)pm have been investigated using the^(107)Ag(^(32)S,2p2n)^(135)pm reaction.Seven rotational bands have been observed in^(135)pm.The yrast band based on a decoupled h_(11/...High-spin states in the odd-proton nucleus^(135)pm have been investigated using the^(107)Ag(^(32)S,2p2n)^(135)pm reaction.Seven rotational bands have been observed in^(135)pm.The yrast band based on a decoupled h_(11/2)proton is found to have a band crossing in ω_(c)~0.43 MeV/h.Two positive-parity bands based on the two signature components of the πg_(7/2)5/2^(+)[413]Nilsson orbital have been observed in the main sidebands.The favoured band with(π,α)=(+,1/2)has been shown to populate below the first pair of proton alignment.Both bands have shown upbend at ω_(1)~0.26 MeV/h and ω_(2)~0.43 MeV/h.These crossing frequencies can be attributed to the decoupling of the first pair of h_(11/2) quasi-proton and h_(11/2) quasi-neutron,respectively.Four weaker bands have been observed in sidebands too.Among them,two states are possibly built on aπd_(5)/23/2^(+)[411]configuration.展开更多
Mean lifetimes of the h_(11/2) quasineutron band in 129Ce were measured by using the Doppler shift attenuation method in connection with the reaction ^(116)Sn(^(l6)O,3n)^(129)Ce at a bombarding energy of 73MeV.The dat...Mean lifetimes of the h_(11/2) quasineutron band in 129Ce were measured by using the Doppler shift attenuation method in connection with the reaction ^(116)Sn(^(l6)O,3n)^(129)Ce at a bombarding energy of 73MeV.The data indicate that transition quadrupole moment of ^(129)Ce is smaller than that of 128Ce.This reduction in collectivity caused by the addition of an h_(11/2) neutron can be interpreted as due to triaxiality induced byγdriving effect.展开更多
Lifetimes of the high spin states in the negative parity band of ^(126)Ba were measured by using the Doppler shift attenuation method in conjunction with the reaction ^(116)Sn(^(16)O,2p4n)^(126) Ba at a beam energy of...Lifetimes of the high spin states in the negative parity band of ^(126)Ba were measured by using the Doppler shift attenuation method in conjunction with the reaction ^(116)Sn(^(16)O,2p4n)^(126) Ba at a beam energy of 73 MeV.This band shows a typically collective behavior and possesses a near-axial prolate shape with a deformation parameter β_(2)=0.27±0.01 and triaxiality γ~-5°.展开更多
High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was est...High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was established up to I^(π)-(23^(-))for the first time.This band shows the signature inversion in energy before backbending generally appeared in this mass region.It is stressed that the signature splitting in 162Lu is larger than that in 160 Tm nucleus.展开更多
High spin states in neutron-deficient ^(117)Xe have been studied by using in-beamγspectroscopy method.A new positive-parity rotational band has been identified.It decays into the yrast vh_(11/2 )band via five electri...High spin states in neutron-deficient ^(117)Xe have been studied by using in-beamγspectroscopy method.A new positive-parity rotational band has been identified.It decays into the yrast vh_(11/2 )band via five electric dipole transitions.The magnitudes of these E1 transitions are extracted and they are much enhanced compared to the normal E1 transitions.This is taken as an evidence for octupole correlations in ^(117)Xe.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.19775070.
文摘The g-factors of the rotational states along the positive parity yrast band in even-even nuclei ^(84)Zr were measured up to a spin I=16^(+)by a transient magnetic field-ion implanted perturbed angular distribution method and calculated by a cranking shell model.A peak structure of the g-factors has been observed for the first time.The measured g-factors confirm the mixed configuration of proton and neutron alignments.
基金Supported by the National Natural Science Foundation of Chinathe Science Foundation of Nuclear Industry of China.
文摘High spin states of the odd-proton nucleus ^(167)Lu have been studied via ^(152)Sm(^(19)F,4n)^(167)Lu reaction at 87MeV beam energy.A weakly populated new rotationa1 band has been observed and assigned as i13/2 proton 1/2^(+)[660] band.This new band and the 1/2^(+)[660] band in ^(171)Ta from the early work are classified as superdeformed bands with triaxiality.
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.19635030the Science Foundation of the Nuclear Industry of China.
文摘High-spin states in^(84)Rb have been studied by using the^(70)Zn(^(18)O,p3n)^(84)Rb reaction at a beam energy of 75 MeV.Theγ-γcoincidence,excitation function and ratios for directional correlation of oriented states were performed.A new level scheme was established in which the positive and negative parity bands have been extended up to 17^(+)and 17^(-)with excitation energy about 7MeV.The signature splitting and signature inversion of the positive parity yrast bands were observed and are discussed.
基金Supported by the National Natural Science Foundation of China under Grant No.19675067.
文摘Structure of high spin states in ^(87)Zr was studied through the reaction ^(59)Co(^(32)S,3pn)^(87)Zr at a beam energy of 118 MeV using in-beam γ-ray spectroscopic method.Measurement of γ-γ coincidence was performed,and directional correlation orientation ratios of someγrays were determined.The level scheme of ^(87)Zr was established up to spin(37/2^(+))and(43/2^(-)).Many previously unknown states have been observed.Comparison with neighboring isotones indicates that the effect of neutron on nuclear structure property is predominant compared to proton,and there is a tendency of reduction in band crossing frequency with increasing proton number.
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.19635030the Science Foundation of the Nuclear Industry of China。
文摘High-spin states in the odd-proton nucleus^(135)pm have been investigated using the^(107)Ag(^(32)S,2p2n)^(135)pm reaction.Seven rotational bands have been observed in^(135)pm.The yrast band based on a decoupled h_(11/2)proton is found to have a band crossing in ω_(c)~0.43 MeV/h.Two positive-parity bands based on the two signature components of the πg_(7/2)5/2^(+)[413]Nilsson orbital have been observed in the main sidebands.The favoured band with(π,α)=(+,1/2)has been shown to populate below the first pair of proton alignment.Both bands have shown upbend at ω_(1)~0.26 MeV/h and ω_(2)~0.43 MeV/h.These crossing frequencies can be attributed to the decoupling of the first pair of h_(11/2) quasi-proton and h_(11/2) quasi-neutron,respectively.Four weaker bands have been observed in sidebands too.Among them,two states are possibly built on aπd_(5)/23/2^(+)[411]configuration.
基金Supported by the National Natural Science Foundation of China under Grant No.19675067the Science Foundation'of Nuclear Industry of China under Grant No.H7196A0115。
文摘Mean lifetimes of the h_(11/2) quasineutron band in 129Ce were measured by using the Doppler shift attenuation method in connection with the reaction ^(116)Sn(^(l6)O,3n)^(129)Ce at a bombarding energy of 73MeV.The data indicate that transition quadrupole moment of ^(129)Ce is smaller than that of 128Ce.This reduction in collectivity caused by the addition of an h_(11/2) neutron can be interpreted as due to triaxiality induced byγdriving effect.
基金Supported by the National Natural Science Foundation of China under Grant No.19675067the Science Foundation of Nuclear Industry of China under Grant No.H7196A0115.
文摘Lifetimes of the high spin states in the negative parity band of ^(126)Ba were measured by using the Doppler shift attenuation method in conjunction with the reaction ^(116)Sn(^(16)O,2p4n)^(126) Ba at a beam energy of 73 MeV.This band shows a typically collective behavior and possesses a near-axial prolate shape with a deformation parameter β_(2)=0.27±0.01 and triaxiality γ~-5°.
基金Supported by the Research Fund of National Post-Doctor Committeethe China National Education Committeethe Chinese Academy of Sciences.
文摘High spin states of the odd-odd ^(162)Lu nucleus have been studied via ^(147)Sm(^(19)F,4nγ)reaction at 95MeV beam energy.Level scheme for yrast band based on π[h_(11/2)]v[i_(13/2)]quasiparticle configuration was established up to I^(π)-(23^(-))for the first time.This band shows the signature inversion in energy before backbending generally appeared in this mass region.It is stressed that the signature splitting in 162Lu is larger than that in 160 Tm nucleus.
基金Supported by the National Natural Science Foundation of China。
文摘High spin states in neutron-deficient ^(117)Xe have been studied by using in-beamγspectroscopy method.A new positive-parity rotational band has been identified.It decays into the yrast vh_(11/2 )band via five electric dipole transitions.The magnitudes of these E1 transitions are extracted and they are much enhanced compared to the normal E1 transitions.This is taken as an evidence for octupole correlations in ^(117)Xe.
