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
Excited states of the odd-odd nucleus 122I are investigated via the fusion-evaporation reaction 116Cd(11B,5n)at a beam energy of 68 MeV.The two most strongly populated bands in 122I are observed up to excitation energ...Excited states of the odd-odd nucleus 122I are investigated via the fusion-evaporation reaction 116Cd(11B,5n)at a beam energy of 68 MeV.The two most strongly populated bands in 122I are observed up to excitation energies around 10.5 MeV.Their possible configurations at lower spins are assigned toπh_(11/2)■νh_(11/2) andπh_(11/2)■νd_(5/2) based on the observed population,B(M1)/B(E2)values,alignments and signature splitting.E1 transitions are observed connecting theπh_(11/2)■νd_(5/2) band to theπh_(11/2)■νh_(11/2) band,which may be evidence of octupole collectivity.Band terminations caused by the full alignment of the valence nucleons outside the 114Sn core are observed in both bands.展开更多
High spin states in the odd-odd nucleus 124Cs have been investigated through the fusion-evaporation reaction 116Sn(11B, 3n)l24 Cs with a beam energy of 45 MeV. A new rotational band is established and assigned as th...High spin states in the odd-odd nucleus 124Cs have been investigated through the fusion-evaporation reaction 116Sn(11B, 3n)l24 Cs with a beam energy of 45 MeV. A new rotational band is established and assigned as the high-k configuration of πg9/2140419/2+ ⊙vh 11/2[523]7/2-. Some structures linking to this band have also been observed. According to the results of the excitation energy systematics, the lowest level of this band is assigned as 9-, and the 8- isomer bandhead has not been observed. Another isomer with a half life of 6.3 s has also been observed with its new decay paths established, Its excitation energy is raised by 79 keV, but its Iπ is not changed.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
High spin states in the odd-A nucleus 113^In have been investigated using the re- action 110^Pd(7^Li, 4n) at a beam energy of 50 MeV. A new positive parity dipole band with the configuration of π(g9/2)^-lv(h11/2...High spin states in the odd-A nucleus 113^In have been investigated using the re- action 110^Pd(7^Li, 4n) at a beam energy of 50 MeV. A new positive parity dipole band with the configuration of π(g9/2)^-lv(h11/2)^2 v (g7/2)^2 is established. The effective interaction V(θ) values of this band have been successfully described by a semiclassical geometric model based on shear mechanism, which show that the dipole band has the characteristics of magnetic rotation. In addition the collective rotational angular momentum for this band is extracted. The results show that the core contribution increases gradually with the increase of the rotation frequency.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
Excited states in^(120)I are investigated utilizing in-beam gamma-ray spectroscopy following the^(114)Cd(^(11)B,5n)reaction at 70 MeV bombarding energy.A level scheme is constructed with states up to 9 MeV.The levels ...Excited states in^(120)I are investigated utilizing in-beam gamma-ray spectroscopy following the^(114)Cd(^(11)B,5n)reaction at 70 MeV bombarding energy.A level scheme is constructed with states up to 9 MeV.The levels are classified into several bands and their possible configurations at low spins are discussed briefly.Based on the linking transitions between different bands at higher spins,the excitation energy of the previously reported T1/2=53 min isomer is ascertained to be 72 keV.Evidence showing the existence of an isomer at an excitation energy of 6.4 MeV is presented.展开更多
High spin states of 128La have been studied through the fusion-evaporation reaction 118Sn(14N,4n) 128La at a beam energy of 69 MeV. A positive-parity side band with the same configuration as that of the yrast band h...High spin states of 128La have been studied through the fusion-evaporation reaction 118Sn(14N,4n) 128La at a beam energy of 69 MeV. A positive-parity side band with the same configuration as that of the yrast band has been identified. Moreover, it is noted that the energy separation △E(I) = E(I)side-E(I)yrast of all doublet bands reported in odd-odd nuclei in the A~130 mass region exhibit a staggering pattern systematically, and they stagger up at even-spin and stagger down at odd-spin.展开更多
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 the National Natural Science Foundation of China(10675053)the National Basic Research Programme of China(2007CB815005)RFDP(20060183048)。
文摘Excited states of the odd-odd nucleus 122I are investigated via the fusion-evaporation reaction 116Cd(11B,5n)at a beam energy of 68 MeV.The two most strongly populated bands in 122I are observed up to excitation energies around 10.5 MeV.Their possible configurations at lower spins are assigned toπh_(11/2)■νh_(11/2) andπh_(11/2)■νd_(5/2) based on the observed population,B(M1)/B(E2)values,alignments and signature splitting.E1 transitions are observed connecting theπh_(11/2)■νd_(5/2) band to theπh_(11/2)■νh_(11/2) band,which may be evidence of octupole collectivity.Band terminations caused by the full alignment of the valence nucleons outside the 114Sn core are observed in both bands.
基金supported by National Natural Science Foundation of China(Nos.10105003,11075064,11075214 and 10927507)the Specialized Research Fund for the Doctoral Programme of Higher Education of China(No.20050183008)the National Basic Research Programme of China(No.2007CB815005)
文摘High spin states in the odd-odd nucleus 124Cs have been investigated through the fusion-evaporation reaction 116Sn(11B, 3n)l24 Cs with a beam energy of 45 MeV. A new rotational band is established and assigned as the high-k configuration of πg9/2140419/2+ ⊙vh 11/2[523]7/2-. Some structures linking to this band have also been observed. According to the results of the excitation energy systematics, the lowest level of this band is assigned as 9-, and the 8- isomer bandhead has not been observed. Another isomer with a half life of 6.3 s has also been observed with its new decay paths established, Its excitation energy is raised by 79 keV, but its Iπ is not changed.
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 National Natural Science Foundation of China (Nos.10105003,11075064,11075214,10927507)the Specialized Research Fund for the Doctoral Programme of Higher Education of China (No.20050183008)National Basic Research Programme of China (No.2007CB815005)
文摘High spin states in the odd-A nucleus 113^In have been investigated using the re- action 110^Pd(7^Li, 4n) at a beam energy of 50 MeV. A new positive parity dipole band with the configuration of π(g9/2)^-lv(h11/2)^2 v (g7/2)^2 is established. The effective interaction V(θ) values of this band have been successfully described by a semiclassical geometric model based on shear mechanism, which show that the dipole band has the characteristics of magnetic rotation. In addition the collective rotational angular momentum for this band is extracted. The results show that the core contribution increases gradually with the increase of the rotation frequency.
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 10675053the National Basic Research Program of China under Grant No 2007CB815005the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20120061110008.
文摘Excited states in^(120)I are investigated utilizing in-beam gamma-ray spectroscopy following the^(114)Cd(^(11)B,5n)reaction at 70 MeV bombarding energy.A level scheme is constructed with states up to 9 MeV.The levels are classified into several bands and their possible configurations at low spins are discussed briefly.Based on the linking transitions between different bands at higher spins,the excitation energy of the previously reported T1/2=53 min isomer is ascertained to be 72 keV.Evidence showing the existence of an isomer at an excitation energy of 6.4 MeV is presented.
基金Supported by National Basic Research Programme of China (2007CB815005)National Natural Science Foundation of China(11075064)Specialized Research Fund for the Doctoral Programme of Higher Education of China (20050183008)
文摘High spin states of 128La have been studied through the fusion-evaporation reaction 118Sn(14N,4n) 128La at a beam energy of 69 MeV. A positive-parity side band with the same configuration as that of the yrast band has been identified. Moreover, it is noted that the energy separation △E(I) = E(I)side-E(I)yrast of all doublet bands reported in odd-odd nuclei in the A~130 mass region exhibit a staggering pattern systematically, and they stagger up at even-spin and stagger down at odd-spin.