Spectroscopy of the low lying states of neutron rich 134 I T. Bhattacharjee 1 , S.K. Das 2 , D. Banerjee 2 , A. Saha 1 , P. Das 1 , S. R. Banerjee 1 , M. Saha Sarkar 3 , S. Sarkar 4 , Karl Johnston 5 , J. G. Correia 5 , Jan Pawel Kurcewicz 5 , Magdalena Kowalska 5 , Jean-Marc Regis 6 1 Physics Group, Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064, India 2 Accelerator Chemistry Section (Bhabha Atomic Research Centre), Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064, India 3 Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India 4 Department of Physics, Bengal Engineering and Science University, Shibpur, Howrah, 711103, India 5 ISOLDE, CERN, CH-1211 Geneve 23, Switzerland 6 Institute of Nuclear Physics, University of Cologne,Zulpicher Str. 77, 50937 Koln, Germany T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
Introduction 132 Sn Nuclei are less studied due to the difficulty in their population, as are away from the line of stability on the neutron rich side of nuclear landscape. Evolution of nuclear structure can be studied with the increase in N/Z ratio – Provides the testing ground for the single particle energy and two body matrix elements near double shell closure of 132 Sn Odd-Odd nuclei allows to verify the p-n interaction matrix elements T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
Motivation Odd-A Iodine ( N ≤ 82): Odd-Odd Iodine (N ≥ 82): Extrapolated Decrease in excitation energy of the 6 - state value of quadrupole moment for 5/2 + st te at shell closure state in odd-odd 136 I(N = 83) and 138 I(N = 85) compared to that of 7/2 + Manifestation of the p d 5/2 anomaly Experiment: |Q| 5/2+ > |Q| 7/2+ ---- Lowering of excitation energy of 5/2 + state of 135 51 Sb 84 Theory : |Q| 7/2+ > |Q| 5/2+ Modified two-body interaction as one Explained as lowering of spe of p d 5/2 orbital moves away towards more neutron in case of 136,138 I rich nuclei Lowering of single particle energy of p d 5/2 D. W. Hafemeister, G. Dzpasquali and D H. Dzwaardf, Phys. Rev.135, B1089(1964). orbital & Change in the n-p interaction Motivating Points: Study of nuclei both in the particle and hole space of neutron compared to N=82 Lifetime and transition moment measurements provide very important information along with conventional g spectroscopy 6/25/2014 T. Bhattacharjee, INTC Meeting, ISOLDE CERN
Why 134 I ? 134 53 I 8 1 121 Sn 122 Sn 123 Sn 124 Sn 125 Sn 126 Sn 127 Sn 128 Sn 129 Sn 130 Sn 131 Sn 132 Sn 122 Sb 123 Sb 124 Sb 125 Sb 126 Sb 127 Sb 128 Sb 129 Sb 130 Sb 131 Sb 132 Sb 133 Sb 131 Te 123 Te 124 Te 125 Te 126 Te 127 Te 128 Te 129 Te 130 Te 132 Te 133 Te 134 Te 124 I 125 I 126 I 127 I 128 I 129 I 130 I 131 I 132 I 133 I 134 I 135 I Three extra proton and single neutron hole Only p-p and p-n interaction is effective as n-n interction can be ignored for low lying states p-p interaction is comparatively better known Unique testing ground for the evolution of p-n interaction with the increase in neutron to proton ratio T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
Why 134 I ? Shell model calculation with 1107 OXBASH code considering 100 Sn as core (present work) 923 Matches with the results from 846 132 Sn core : L. Coraggio et al., Phys. Rev. C80, With 5 + of 79 keV With 3 + of 79 keV 061303(R) (2009). state state 645 Shows important results t = 0.06 ns t = 2 ns Q = 0.3 eb Q = 0.02 eb Position of calculated 3 + and 316 5 + states reversed compared to that of present status of 210 < 0.15 ns expt. < 0.1ns 180 79 1.62 ns Important to confirm the spin 44 < 10ns 0 of 79 keV level, whether it is really inversed or prediction of 5 + is different Incomplete experimental information Previous experiments done with Ge(Li) and e- g coincidence setup T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
Experimental Plan T. Bhattacharjee, INTC Meeting, 6/25/2014 ISOLDE CERN
Scope of the proposed experiment – Part I Three HPGe detectors 0 + 41.8 min b - 134 52 Te 82 134 Te collected in Al foil and will be dissolved in 923.43 1+ acid. 846.68 Angular correlation analysis using ANGCORR code 1+ ( p d 5/2 n d 3/2 ) 645.47 (2,3)+ Necessary to measure lifetime and quadrupole moments R. A. Meyer et al., Phys. Rev. C13 , 1617(1976). ( p g 7/2 n s 1/2 ) <0.15 ns 210.45 (2,3)+ < 0.1 ns 180.87 ( p g 7/2 n d 3/2 ) (2,3)+ 1.62 ns 79.46 (3)+ 44.40 (5)+ 0.0 52.5 min (4)+ 134 53 I 81 BRiCC : d = 0.03 (3 + ) g-g coincidence, Intensity and angular correlation measurement: d = 0.005 (5 + ) Confirm spin of 79 keV , l80 keV level Confirm spin of 79 keV , l80 keV level Confirm spin of 79 keV , l80 keV level Confirm spin of 210 keV level Confirm spin of 210 keV level Confirm spin of 645 keV level T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
Scope of the proposed experiment – Part II Lifetime 0 + 41.8 min measurement from b - 134 52 Te 82 electron gamma coincidence 923.43 V. Berg and A. 1+ Hoglund, Nuclear 846.68 1+ Physics Al75, 495 } ( p d 5/2 n d 3/2 ) (1971). 645.47 (2,3)+ } ( p g 7/2 n s 1/2 ) } ( p g 7/2 n s 1/2 ) <0.15 ns 210.45 (2,3)+ < 0.1 ns 180.87 ( p g 7/2 n d 3/2 ) ( p g 7/2 n d 3/2 ) (2,3)+ 1.62 ns 79.46 (3)+ 44.40 (5)+ 0.0 52.5 min (4)+ Two LaBr 3 (Ce) detectors 134 53 I 81 Lifetime measurement 134 Te collected in Al foil and will Confirm lifetime of 79 keV level , measure for 180 keV Confirm lifetime of 79 keV level , measure for 180 keV Confirm lifetime of 79 keV level , measure for 180 keV be dissolved in acid level level level Lifetime of 210 keV level Lifetime of 210 keV level Slope or de-convolution technique Lifetime of 645 keV level Mirror Symmetric Centroid Difference Technique T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
Scope of the proposed experiment – Part III Qudrupole moment 0 + 41.8 min measurement of the 79 b - 134 52 Te 82 keV level 923.43 1+ 846.68 1+ 645.47 <0.15 ns 210.45 < 0.1 ns 180.87 ( p g 7/2 n d 3/2 ) (2,3)+ 1.62 ns 79.46 (3)+ 44.40 (5)+ 0.0 52.5 min (4)+ DIGIPAC facility with six LaBr 3 (Ce) 134 53 I 81 detector at ISOLDE Perturbed Angular Correlation technique 134 Te will be collected in Te metal matrix Electric field gradient (EFG) ( calculated from Wien2K and/or estimate from 132 I in XII-plan,Accelerator Chemistry 6/23/2014 45 T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014 Section,RCD,VECC Te matrix)
Beam Time Requirement vs Plan 12-15 irradiations with 134 Te beam of activity ~10 8-10 ions/sec 1 Collection = 30-60 minutes ; with suitable gap between each collection – Times may be varied depending on the available ions/sec ~9 irradiations will be in Al-foil ; Rest will be in Te metal with online annealing Contamination: Isobaric Contamination will not be a problem as the isobaric neighbors have very short half lives (~ secs) compared to 42 mins half life for 134 Te Only isobaric activity of 134 I (52 mins) will be there anyway as a part of the measurement. Contaminant g -lines (keV) (per 100 decay of 134 I ground state): 847 (96); 884(65); 1072(15); 621(10); 677(8); 405(8); 540(7); 135(5); 947(4); 766(4) T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
In a Nutshell The combined measurement of angular correlation, lifetime and quadrupole moment will be performed. Provide important information on the nuclear structure for the neutron rich 134 I nucleus around double shell closure of 132 Sn. The unique testing ground for n-p interaction in odd-odd 134 I , with a single neutron hole compared to N = 82. T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014
Details of the Experimental Techniques to be used T. Bhattacharjee et al., Phys. Rev. C88, 014313 (2013) EPJ Web of Conferences 66 , 02009(2014). MSCD technique for ps lifetime Slope OR De-convolution 131 I : technique for ns lifetime (81-102) keV TDPAC technique E x = 1899 keV 0.2 for Q-pole moment Q = 275.26 (15.07) MHz 1000 Q ~ Q* V zz No. of Events 0.1 134 Te in Te metal 200 matrix A 2 G 2 (t) (102-81) keV 0.0 Wien2K code for 1000 the determination -0.1 132 Te in Te of V zz theoretically metal matrix 200 188.0 188.5 189.0 189.5 190.0 190.5 191.0 191.5 192.0 -0.2 T. Bhattacharjee et 0 1 2 3 4 5 6 Time (ns) al., Communicated Time (ns) T. Bhattacharjee, INTC Meeting, ISOLDE CERN 6/25/2014 to HFI-NQI 2014
T. Bhattacharjee, INTC Meeting, 6/25/2014 ISOLDE CERN
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