Spectroscopy of the low lying states of neutron rich 134 I T. - - PowerPoint PPT Presentation

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Spectroscopy of the low lying states of neutron rich 134 I T. - - PowerPoint PPT Presentation

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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 ,

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SLIDE 1

Spectroscopy of the low lying states of neutron rich 134I

6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN
  • T. Bhattacharjee1, S.K. Das2, D. Banerjee2, A. Saha1, P. Das1, S. R. Banerjee1, M. Saha

Sarkar3, S. Sarkar4, Karl Johnston5, J. G. Correia5, Jan Pawel Kurcewicz5, Magdalena Kowalska5, Jean-Marc Regis6

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

3Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India 4Department of Physics, Bengal Engineering and Science University, Shibpur, Howrah, 711103,

India

5ISOLDE, CERN, CH-1211 Geneve 23, Switzerland 6Institute of Nuclear Physics, University of Cologne,Zulpicher Str. 77, 50937 Koln, Germany

slide-2
SLIDE 2

132Sn

Introduction

6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN
  • 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 132Sn

  • Odd-Odd nuclei allows to verify the p-n interaction matrix elements
  • 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.

slide-3
SLIDE 3

Motivation

Odd-A Iodine ( N ≤ 82):

  • Extrapolated

value

  • f

quadrupole moment for 5/2+ st state te at shell closure compared to that of 7/2+

  • Experiment: |Q|5/2+ > |Q|7/2+
  • Theory : |Q|7/2+ > |Q|5/2+
  • Modified two-body interaction as one

moves away towards more neutron rich nuclei

6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN

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 Odd-Odd Iodine (N ≥ 82):  Decrease in excitation energy of the 6- state in odd-odd 136I(N = 83) and 138I(N = 85) Manifestation of the pd5/2 anomaly

  • --- Lowering of excitation energy of

5/2+ state of 135

51Sb84

 Explained as lowering of spe of pd5/2 orbital in case of 136,138I  Lowering of single particle energy of pd5/2

  • rbital & Change in the n-p interaction
  • D. W. Hafemeister, G. Dzpasquali and D H.

Dzwaardf, Phys. Rev.135, B1089(1964).

slide-4
SLIDE 4

6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN

126I

127I 128I 129I 130I

125Te

126Te 127Te 128Te 129Te

124Sb

125Sb 126Sb 127Sb 128Sb

123Sn

124Sn 125Sn 126Sn 127Sn

131I

132I 133I 134I 135I 130Te 131Te 132Te 133Te 134Te

129Sb

130Sb 131Sb 132Sb 133Sb 128Sn 129Sn 130Sn 131Sn 132Sn

121Sn

122Sn

122Sb

123Sb

123Te

124Te

124I

125I

134 53I8 1

Why 134I ?

 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

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SLIDE 5

< 0.15 ns < 0.1ns 1.62 ns 44 79 210 180 < 10ns 645 846 923 1107 316 6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN
  • Shell model calculation with

OXBASH code considering 100Sn as core (present work)

  • Matches with the results from

132Sn core : L. Coraggio et al., Phys. Rev. C80,

061303(R) (2009).

  • Shows important results

Why 134I ?

  • Position of calculated 3+ and

5+ states reversed compared to that of present status of expt.

  • Important to confirm the spin
  • f 79 keV level, whether it is

really inversed or prediction

  • f 5+ is different

With 5+ of 79 keV state t = 0.06 ns Q = 0.02 eb With 3+ of 79 keV state t = 2 ns Q = 0.3 eb

 Incomplete experimental information  Previous experiments done with Ge(Li) and e-g coincidence setup

slide-6
SLIDE 6

6/25/2014

  • T. Bhattacharjee, INTC Meeting,

ISOLDE CERN

Experimental Plan

slide-7
SLIDE 7

Scope of the proposed experiment – Part I

g-g coincidence, Intensity and angular correlation measurement:

  • Three HPGe detectors
  • 134Te collected in Al foil

and will be dissolved in acid.

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN

6/25/2014

  • R. A. Meyer et al.,
  • Phys. Rev.C13,

1617(1976).

0.0 79.46 180.87 210.45 44.40 923.43 846.68 645.47 (4)+ (5)+ 1+ 1+ 52.5 min <0.15 ns < 0.1 ns 1.62 ns

41.8 min 0+

134 52Te82

b-

134 53I81

(2,3)+ (3)+

 Confirm spin of 79 keV , l80 keV level

(pg7/2nd3/2)

(2,3)+

 Confirm spin of 210 keV level

(pg7/2ns1/2)

 Confirm spin of 79 keV , l80 keV level

(2,3)+

 Confirm spin of 645 keV level

(pd5/2nd3/2)

 Confirm spin of 210 keV level  Confirm spin of 79 keV , l80 keV level

Angular correlation analysis using ANGCORR code Necessary to measure lifetime and quadrupole moments BRiCC : d = 0.03 (3+) d = 0.005 (5+)

slide-8
SLIDE 8

Lifetime measurement

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN

6/25/2014

0.0 79.46 180.87 210.45 44.40 923.43 846.68 645.47 (4)+ (5)+ 1+ 1+ 52.5 min <0.15 ns < 0.1 ns 1.62 ns

Scope of the proposed experiment – Part II

(2,3)+ (3)+

(pg7/2nd3/2)

 Confirm lifetime of 79 keV level , measure for 180 keV level

Lifetime measurement from electron gamma coincidence

  • V. Berg and A.

Hoglund, Nuclear Physics Al75, 495 (1971).

41.8 min 0+

134 52Te82

b-

134 53I81

(2,3)+

}(pg7/2ns1/2)

 Lifetime of 210 keV level  Confirm lifetime of 79 keV level , measure for 180 keV level

(2,3)+

}(pd5/2nd3/2)

 Lifetime of 645 keV level  Lifetime of 210 keV level  Confirm lifetime of 79 keV level , measure for 180 keV level

}(pg7/2ns1/2)

(pg7/2nd3/2)

  • Two LaBr3 (Ce) detectors
  • 134Te collected in Al foil and will

be dissolved in acid

  • Slope or de-convolution

technique

  • Mirror Symmetric Centroid

Difference Technique

slide-9
SLIDE 9
  • DIGIPAC facility with six LaBr3(Ce)

detector at ISOLDE

  • Perturbed Angular Correlation technique
  • 134Te will be collected in Te metal matrix
  • Electric field gradient (EFG) ( calculated

from Wien2K and/or estimate from 132I in Te matrix)

6/23/2014 XII-plan,Accelerator Chemistry Section,RCD,VECC 45

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN

6/25/2014

0.0 79.46 180.87 210.45 44.40 923.43 846.68 645.47 (4)+ (5)+ 1+ 1+ 52.5 min <0.15 ns < 0.1 ns 1.62 ns (2,3)+ (3)+

(pg7/2nd3/2)

Qudrupole moment measurement of the 79 keV level

Scope of the proposed experiment – Part III

41.8 min 0+

134 52Te82

b-

134 53I81

slide-10
SLIDE 10

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 134Te Only isobaric activity of 134I (52 mins) will be there anyway as a part of the measurement. Contaminant g-lines (keV) (per 100 decay of 134I ground state): 847 (96); 884(65); 1072(15); 621(10); 677(8); 405(8); 540(7); 135(5); 947(4); 766(4)

Beam Time Requirement vs Plan

6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN

12-15 irradiations with 134Te beam of activity ~108-10 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

slide-11
SLIDE 11

6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN
  • The combined measurement of angular correlation, lifetime and quadrupole

moment will be performed.

  • Provide important information on the nuclear structure for the neutron rich 134I

nucleus around double shell closure of 132Sn.

  • The unique testing ground for n-p interaction in odd-odd 134I , with a single

neutron hole compared to N = 82. In a Nutshell

slide-12
SLIDE 12

6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN
slide-13
SLIDE 13

Details of the Experimental Techniques to be used

6/25/2014

  • T. Bhattacharjee, INTC Meeting, ISOLDE CERN

1 2 3 4 5 6

  • 0.2
  • 0.1

0.0 0.1 0.2

A2G2(t) Time (ns)

Q = 275.26 (15.07) MHz Q ~ Q* Vzz

TDPAC technique for Q-pole moment

134Te in Te metal

matrix Wien2K code for the determination

  • f Vzz theoretically
  • T. Bhattacharjee et

al., Communicated to HFI-NQI 2014

132Te in Te

metal matrix

200 1000 188.0 188.5 189.0 189.5 190.0 190.5 191.0 191.5 192.0 200 1000

  • No. of Events

(81-102) keV

Time (ns)

(102-81) keV

131I :

Ex = 1899 keV

MSCD technique for ps lifetime

  • T. Bhattacharjee

et al., Phys. Rev. C88, 014313 (2013)

Slope OR De-convolution technique for ns lifetime

EPJ Web of Conferences 66, 02009(2014).

slide-14
SLIDE 14

6/25/2014

  • T. Bhattacharjee, INTC Meeting,

ISOLDE CERN