A new band in the odd proton nucleus ^123I is identified via in-beam γ-ray spectroscopy using the ^14N＋^116Cd reaction. This band shows up as doublets with the previously assigned π97/2 （vh11/2）^2 band. Possible...A new band in the odd proton nucleus ^123I is identified via in-beam γ-ray spectroscopy using the ^14N＋^116Cd reaction. This band shows up as doublets with the previously assigned π97/2 （vh11/2）^2 band. Possible configurations of the new band are discussed in the framework of the cranked shell model and the geometrical model It is argued that the new band might be a chiral partner of the previously known πg9/2 （vh11/2）2 band.展开更多
High-spin states in ^129Cs are populated via the ^122Sn （^11B, 4n） reaction at beam energies of 55 and 60MeV. Two additional bands are placed in the level scheme and the previously known bands are extended to higher...High-spin states in ^129Cs are populated via the ^122Sn （^11B, 4n） reaction at beam energies of 55 and 60MeV. Two additional bands are placed in the level scheme and the previously known bands are extended to higher spins. The results are compared to the cranked shell model calculations and to the systematics of the adjacent Cs isotpoes. One of the new bands is interpreted as the 7-vibrational band built on the πh11/2 orbital. The possible configuration for another new band is discussed. Upbend caused by （Vh11/2）^2 alignment is observed both in the favored and unfavored sequences of the πh11/2 configuration. The band based on the πgτ/2 configuration at low spins forks around spin 17//2, and the two different S-bands are attributed to （Vh11/2）^2 and （πh11/2）^2 rotational alignments, respectively.展开更多
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 evap- oration reaction 124Sn（11B; 5n）130C...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 evap- oration 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.展开更多
High spin states of the odd-odd nucleus 122^Ⅰ have been investigated via the fusion- evaporation reaction 116^Cd（11^B, 5n） at a beam energy of 68 MeV. The yrast band is extended up to Ⅰ^π= （29＋）. The band term...High spin states of the odd-odd nucleus 122^Ⅰ have been investigated via the fusion- evaporation reaction 116^Cd（11^B, 5n） at a beam energy of 68 MeV. The yrast band is extended up to Ⅰ^π= （29＋）. The band termination at Ⅰ^π= （22^＋） reported in previous studies is confirmed and interpreted as arising from a shape change from collective prolate to noncollective oblate according to Total-Routhian-Surface （TRS） calculations. In addition, the Ⅰ^π=（29^＋） state is assigned to the [πh^11/2 （πg7/2）^2]23/2- [（vhll/2）^3 （vd5/2）^2]35/2- configuration corresponding to the full alignment of all valance nucleons outside the semi-closed shell.展开更多
t The excited states of the doubly-odd 120^Ⅰ have been investigated via the 110^Pd（14^N, 4n） and the 114^Cd（10^B, 4n） reactions at beam energies of 64 MeV and 48 MeV, re-spectively. The previously known bands are...t The excited states of the doubly-odd 120^Ⅰ have been investigated via the 110^Pd（14^N, 4n） and the 114^Cd（10^B, 4n） reactions at beam energies of 64 MeV and 48 MeV, re-spectively. The previously known bands are extended, and a new band structure is established. The yrast band is assigned to the πrh11/2 vh11/2 configuration instead of the previously as- signed πg7/2 vh11/2 configuration. Possible configurations of the other observed bands are also discussed.展开更多
High-spin states of ^160Tm are studied by the ^146 Nd（^19F, 5n） reaction at a beam energy of 102 MeV. The previously known πh11/2 ＋ vi13/2 yrast band and πh11/2 ＋ vh9/2 side band are confirmed. The level scheme ...High-spin states of ^160Tm are studied by the ^146 Nd（^19F, 5n） reaction at a beam energy of 102 MeV. The previously known πh11/2 ＋ vi13/2 yrast band and πh11/2 ＋ vh9/2 side band are confirmed. The level scheme is enriched and more low-lying levels are observed. A new side band is observed and assigned as the favoured signature partner of πd3/2 ＋ vi13/2. The spin of this band is assigned with the energy level systematics. It is pointed out that the B （M1）/B （E2） ratios increase rapidly at the high frequency approaching the second crossing in the π h11/2 ＋ vi13/2 braid, which is closely related to the alignment gain of the aligned i13/2 quasineutron.展开更多
Lifetimes of high spin states in 129Cs axe measured using the Doppler shift attenuation method. The high spin states of 129 Cs axe populated following the fusion evaporation reaction 124 Sn（UB, 6n）129 Cs at a beam e...Lifetimes of high spin states in 129Cs axe measured using the Doppler shift attenuation method. The high spin states of 129 Cs axe populated following the fusion evaporation reaction 124 Sn（UB, 6n）129 Cs at a beam energy of 65 MeV. The reduced transition probabilities B（E2） and the transition quadrupole moments Qt in the negativeand positive-paxity 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 γ-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 πh11/2 and πg7/2 bands shows the opposite changing trend after backbending due to the h11~2 neutron and h11/2 proton alignments, respectively.展开更多
Low-lying and high-spin states of ^124 Cs 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 y...Low-lying and high-spin states of ^124 Cs 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 vd3/2 bands and two transitions between the yrast and πh11/2 v（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 finking transitions between the yrast and πh11/2 v（d5/2, 97/2） bands observed before. These E1 linking transitions infer the oetupole correlation in ^124Cs. 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 vd3/2 configuration.展开更多
基金Supported by the National Natural Science Foundation of China under Grant 10675053, the National Basic Research Program of China under Grant No 2007CB815005） and the Specialized Research Fund for the Doctoral Programme of Higher Education of China under Grant No 20060183048.
文摘A new band in the odd proton nucleus ^123I is identified via in-beam γ-ray spectroscopy using the ^14N＋^116Cd reaction. This band shows up as doublets with the previously assigned π97/2 （vh11/2）^2 band. Possible configurations of the new band are discussed in the framework of the cranked shell model and the geometrical model It is argued that the new band might be a chiral partner of the previously known πg9/2 （vh11/2）2 band.
基金Supported by the National Natural Science Foundation of China under Grant No 10675053, the National Basic Research Program of China under Grant No 2007CB815005, and the Specialized Research Fund for the Doctoral Programme of Higher Education of China under Grant No 20060183048.
文摘High-spin states in ^129Cs are populated via the ^122Sn （^11B, 4n） reaction at beam energies of 55 and 60MeV. Two additional bands are placed in the level scheme and the previously known bands are extended to higher spins. The results are compared to the cranked shell model calculations and to the systematics of the adjacent Cs isotpoes. One of the new bands is interpreted as the 7-vibrational band built on the πh11/2 orbital. The possible configuration for another new band is discussed. Upbend caused by （Vh11/2）^2 alignment is observed both in the favored and unfavored sequences of the πh11/2 configuration. The band based on the πgτ/2 configuration at low spins forks around spin 17//2, and the two different S-bands are attributed to （Vh11/2）^2 and （πh11/2）^2 rotational alignments, respectively.
基金supported by the Major State Basic Research Development Program (2007CB815000)National Natural Science Foundation of China (Nos. 10775184, 10675171, 10575133, 10575092, 10375092)
文摘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 evap- oration 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.
基金supported by National Natural Science Foundation of China (Nos.10675053,10475033)National Basic Research Program of China(No.2007CB815005)
文摘High spin states of the odd-odd nucleus 122^Ⅰ have been investigated via the fusion- evaporation reaction 116^Cd（11^B, 5n） at a beam energy of 68 MeV. The yrast band is extended up to Ⅰ^π= （29＋）. The band termination at Ⅰ^π= （22^＋） reported in previous studies is confirmed and interpreted as arising from a shape change from collective prolate to noncollective oblate according to Total-Routhian-Surface （TRS） calculations. In addition, the Ⅰ^π=（29^＋） state is assigned to the [πh^11/2 （πg7/2）^2]23/2- [（vhll/2）^3 （vd5/2）^2]35/2- configuration corresponding to the full alignment of all valance nucleons outside the semi-closed shell.
基金supported by National Natural Science Foundation of China (No.10675053)National Basic Research Program of China(No.2007CB815005)
文摘t The excited states of the doubly-odd 120^Ⅰ have been investigated via the 110^Pd（14^N, 4n） and the 114^Cd（10^B, 4n） reactions at beam energies of 64 MeV and 48 MeV, re-spectively. The previously known bands are extended, and a new band structure is established. The yrast band is assigned to the πrh11/2 vh11/2 configuration instead of the previously as- signed πg7/2 vh11/2 configuration. Possible configurations of the other observed bands are also discussed.
基金Supported by the National Natural Science Foundation of China under Grant No 10105003, the Specialized Research Fund for the Doctoral Programme of Higher Education of China under Grant No 20050183008, and the National Basic Research Programme of China under Grant No 2007CB815000.
文摘High-spin states of ^160Tm are studied by the ^146 Nd（^19F, 5n） reaction at a beam energy of 102 MeV. The previously known πh11/2 ＋ vi13/2 yrast band and πh11/2 ＋ vh9/2 side band are confirmed. The level scheme is enriched and more low-lying levels are observed. A new side band is observed and assigned as the favoured signature partner of πd3/2 ＋ vi13/2. The spin of this band is assigned with the energy level systematics. It is pointed out that the B （M1）/B （E2） ratios increase rapidly at the high frequency approaching the second crossing in the π h11/2 ＋ vi13/2 braid, which is closely related to the alignment gain of the aligned i13/2 quasineutron.
基金Partially supported by the National Basic Research Development Program of China under Grant No 2007CB815000, and the National Natural Science Foundation of China under Grant Nos 10775184, 10675171, 10575133, 10575092 and 10375092.
文摘Lifetimes of high spin states in 129Cs axe measured using the Doppler shift attenuation method. The high spin states of 129 Cs axe populated following the fusion evaporation reaction 124 Sn（UB, 6n）129 Cs at a beam energy of 65 MeV. The reduced transition probabilities B（E2） and the transition quadrupole moments Qt in the negativeand positive-paxity 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 γ-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 πh11/2 and πg7/2 bands shows the opposite changing trend after backbending due to the h11~2 neutron and h11/2 proton alignments, respectively.
基金Supported by the National Natural Science Foundation of China under Grant No 10105003, the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 20050183008, and the National Basic Research Program of China under Grant No 2007CB815000.
文摘Low-lying and high-spin states of ^124 Cs 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 vd3/2 bands and two transitions between the yrast and πh11/2 v（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 finking transitions between the yrast and πh11/2 v（d5/2, 97/2） bands observed before. These E1 linking transitions infer the oetupole correlation in ^124Cs. 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 vd3/2 configuration.
