1. Magdalena Kowalska ( Contact person)
Experimental investigation of decay properties of neutron deficient Ba isotopes and test of Ba beam counts
Ushasi Datta Pramanik (Spokesperson)
Saha Institute of Nuclear Physics, Kolkata
Olof Tengblad (Co-spokesperson)
Inst. de Estructura de la Materia, CSIC, Madrid, Spain
Magdalena Kowalska ( Contact person)
ISOLDE, CERN)
2nd Feb., 2012

2. many interesting structure arise
Decoupling of proton and neutron
many interesting structure arise
PIGMY resonance / Low –lying dipole strength observed both proton and neutron-rich nuclei
Clustrization
Can study through decay
Exotic decay mode
-delayed three proton decay
Two-proton radio activity
 Alpha decay
Decay of Intermediate Mass Fragments
Schematic Diagram of nuclear potential

3. Physics Interest
Systematic study of decay properties of nuclei near proton-drip line
Mass region A~ near proton drip line are enriched with a large variety of structural information
Predicted as “a new island of cluster”
Exotic decay modes
beta delayed proton, beta delayed alpha
heavier exotic clusters
First , 14C clusters, H. Rose et al, Nature 307
BARDWICK, et al PRC 34, (Rap. Comm)1986
ISOLDE, 3rd November 2011

4. AIM: Systematic study of decay properties of 114-118Ba
Study of detailed delayed proton and alpha decay
What we can learn!!!!!
> Resonance states, Quasi bound proton, alpha states
>Coupling to continuum
ISOLDE, 3rd November 2011

5. For Ba isotopes , what we can expect!!!!!!
Systematic reduction of alpha decay width, experimentally observe (Te-Xe) Cluster structure
For Ba isotopes , what we can expect!!!!!!
Test of theoretical model near drip line, residual interaction,
Z.Janas et al ,EPJ PN-QRPA cannot explain 117Ba decay data was not explained by pn-QRPS, residual interaction!!!!!
Decay from even-even to odd-odd isotope may give important information
regarding , pairing and n-p interaction near drip line
I. Hamamoto, PRC 48; 1993

6. Test of 112-115Ba beam counts for future measurement
Motivation for future measurement
112Ba (N=Z) , not known (half life, etc.)
 Search for super allowed alpha decay
112Ba Xe Te Sn
Delayed proton, alpha, exotic cluster decay mode
Systematic reduction of alpha width in medium heavy nuclei Cluster structure
Neutron-proton pairing

7. Mainly explored by Fusion Evaporation Will measure using exotic beam
AZBa
Delayed Proton/alpha decay b+
Decay properties in this region
AZ-1Cs
Mainly explored by Fusion Evaporation
Will measure using exotic beam p
A-1Z-2Xe
Properties of proton orbital
Single particle structure
Nuclear shapes
Nuclear life-times
of the daughter (Cs)
Properties of proton orbital
Single particle structure
Nuclear shapes
Nuclear life-times
of the Parent (Ba)

8. Exclusive decay mode in this mass region 110I ,
Schardt et al, NPA 368, 153, (1981)
Only 117Ba, delayed proton decay studied , Z. Janas et al EPJ 2005

9. 118Ba, 117Ba, 116Ba 115Ba Identification of b-delayed
Proton, but no prior
Information About
b-delayed a
Z. Janas et al [1]
115Ba
b-delyed proton identified
by Janas et al [1]
half life by
Guglielmetti et al [2]
114Ba
Cluster decay studied by
Oganessian et al[3],
Guglielmetti et al[4,5] with contradiction ;
a-decay studied by
Mazzocchi et al [6]
[1] Z. Janas; NPA 627
[2] Guglielmetti; NPA 583
[3] Oganessian; ZPA 349
[4] Guglielmetti; PRC 52
[5] Guglielmetti; PRC 56
[6] Mazzocchi; PLB 532
[7] Hecht ; AIP Conf.Proc. 819
113Ba
Only 1 experimental study by
Hecht et al [7], but no
information about decay
112Ba
No experimental
study

10. Experiment Aim: To measure the exotic decay mode of 116-118Ba
To measure life time of the nuclear level isotopes (proton unbound state)
Beam development/statistics of Ba
Shifts required:
(real measurement)
118Ba ( t1/2 ~5.5 sec) (105/sec) 6 shifts (p~ 4x10-4/sec, ~ 4x10-5/sec
117Ba ( t1/2 ~1.75 sec) ----(104/sec ) 6 shifts (p~ 0.13/sec, ~ 4x10-4/sec
116Ba ( t1/2 ~1.35 sec) (104/sec ) 6 shifts ((p~ 0.03/sec, ~ 4x10-4/sec
Ba ( t1/2 < 1 sec) ---(beam count 4 shifts for future studies)
Total …….22 shifts.
ISOLDE, 3rd November 2011
ISOLDE, 3rd November 2011

11. Experimental Set-up::
Measurement delayed proton, alpha,
X or g-ray in coincident with delayed p or alpha
Measurement of nuclear level lifetime of the order of sub pico-seconds or femto- seconds
( sec

12. Collaborators
J. Ray1, P. Bhattacharya1, A. Becerril2, Y. Blumenfeld3, M. J.G. Borge2, S.Chakraborty1, S. Chatterjee1, L.M.Fraile3, H.O.U. Fynbo4, A. Heinz5, B. Jonson5,
K.Kar1, U. Köster6, M. Kowalska3, S.Mandal7, B.Mukherjee8, E. Nacher2, T. Nilsson5, G. Nyman5, K. Riisager4, A. Rahaman1, P. Reiter9,
T. Stora3, P.J.Wood 10
1Saha Institute Of Nuclear Physics, Kolkata, India
2Inst. de Estructura de la Materia, CSIC, Madrid, Spain
3ISOLDE, CERN, France
4Dept. of Physics and Astronomy, Aarhus Univ., DK-8000 Aarhus C, Denmark
5Fundamental Fysik, Chalmers Tekniska Hogskola, S Goteborg, Sweden
6IIL, Grenoble, France, 7University of Delhi, India, 8University of Viswa Bharati,India
9Institut fuer Kernphysik, Universitaet zu Koeln, D-50937, Koeln
10, University of Edinburgh, EH93JZ, UK
ISOLDE, 2nd , Feb, 2012

13. ISOLDE, 3rd November 2011

14. ISOLDE, 3rd November 2011

15. ISOLDE, 3rd November 2011

16. 112Ba 108Xe 112Cs 104Te 111Xe 108I 100Sn b+ a a p a a 0.5 ms 0.81s
Qb+ = 9200 keV
Qa = 4200 keV
ba = ? b+ a
0.5 ms
108Xe
Qa = ?
ba = ?
112Cs
Qp = 814 KeV
bp = 100% a
Qa = 3930 KeV
ba = p
0.81s
104Te
Qa = ?
ba = ?
111Xe a a
36 ms
108I
100Sn

17. 114Ba 110Xe 114Cs 106Te 113Xe 110I 102Sn b+ a a p a a 0.43s 93 ms
Qb+ = 7700 keV
Qa = 1480 keV
ba = 0.9% b+ a
93 ms
0.57s
110Xe
Qa = 3870 KeV
ba = 64%
114Cs
Qp =
bp = a
Qa = 3360 KeV
ba < 0.1% p
70 ms
106Te
Qa = 1660 Kev
ba = 100%
2.74s
113Xe a a
0.65s
0.43s
110I
102Sn

18. 114-118Ba isotopes – special interest
Very close to the proton drip line and in the mass region we are interested in (A~ )
ISOLDE, 3rd November 2011

19. 114-118Ba isotopes – special interest
more than 20 theoretical predictions on cluster decay,
Experiments in contradiction with each other
Phys.Rev. C51, 594 (1995)
D. N. Poenaru predicted emission of
12C from 114Ba
Guglielmetti (1995), NPA583
12C from 114Ba
Ba decay
Z.Janas NPA 627 (1997)119
PRC56, R2912 (1997) Guglielmetti shows non-observation of 12C from 114Ba
ISOLDE, 3rd November 2011
ISOLDE, 3rd November 2011

20. Collaborators
J. Ray1, P. Bhattacharya1, A. Becerril2, Y. Blumenfeld3, M. J.G. Borge2, S.Chakraborty1, S. Chatterjee1, L.M.Fraile3, H.O.U. Fynbo4, A. Heinz5, B. Jonson5,
K.Kar1, U. Köster6, M. Kowalska3, S.Mandal7, B.Mukherjee8, E. Nacher2, T. Nilsson5, G. Nyman5, K. Riisager4, A. Rahaman1, P. Reiter9,
T. Stora3, O. Tengblad2
1Saha Institute Of Nuclear Physics, Kolkata, India
2Inst. de Estructura de la Materia, CSIC, Madrid, Spain
3ISOLDE, CERN, France
4Dept. of Physics and Astronomy, Aarhus Univ., DK-8000 Aarhus C, Denmark
5Fundamental Fysik, Chalmers Tekniska Hogskola, S Goteborg, Sweden
6IIL, Grenoble, France, 7University of Delhi, India, 8University of Viswa Bharati,India
9Institut fuer Kernphysik, Universitaet zu Koeln, D-50937, Koeln
ISOLDE, 2nd , Feb, 2012