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Study of the Shell Evolution Effect on the Nuclei around the 78Ni Core Structure

Yıl 2019, , 109 - 113, 27.12.2019
https://doi.org/10.17678/beuscitech.633561

Öz











 



              Bitlis
Eren Universıty  Journal of scıence and
technology
00 (2013) 000–000                               



 





 



 


 


 


 


 



Available online at www.dergipark.ulakbim.gov.tr/beuscitech/


 


Journal of
Science and Technology


 


                                                                E-ISSN 2146-7706                                                                                                



 




 





Study of the shell evolution effect on the nuclei structure around the 78Ni core 





 



Nadjet Laouet * , Fatima Benrachi, Habiba Guerraiche, Karima Benhizia



LPMPS Laboratory, Frères Mentouri Constantine-1, 25107,Constantine Algeria




A
R T I C L E  I N F O



Article history:


Received 00 December 0000


Received in revised form 00 January 0000


Accepted 00 February 0000



 



Keywords:


Nuclear shell model

Doubly magic core 78Ni

Monopole interaction

Nuclear structure properties

NuShellX@MSU code




 



A
B S T R A C T







 1. Introduction



Nuclei close to doubly magic cores that are in the
limit of the nuclear chart are good candidate to test new theoretical
predictions in order to explain the experimental observations in such systems.
Experimental studies and spectroscopic calculations, in these regions, can
prove and expect new phenomena as the disappearance of some habitual magic
numbers and the appearance of new ones (Dobaczewski et al., 1994; Otsuka et
al., 2005). These observations may result from the so-called shell evolution.
78Ni
is one of the best exotic doubly magic cores, which is considered as the
closest core to the neutron drip-line. This region offers best opportunity to
develop a comprehensive understanding of shell evolution.



In this context, we have studied N=52 isotones, which
cover a large range from the neutron drip line to the neutron one near 78Ni
core. Indeed, there are few experimental data in the considered mass region.
78Ni is an exotic nucleus that situated in the limit of nuclear chart and it is
very difficult to study experimentally. The two neutrons in N=52 isotones are
situated on
d5/2 shell for low excitation
energies. For high ones, one or two neutron can move to other orbits. These
isotones have been studied by (Czerwinski et al., 2013). In their work, the
86Se
and
88Kr nuclei have been investigated following,
respectively, spontaneous fissions of
248Cm and 252Cf
by means of prompt-
g
-ray-spectroscopy methods using the Gamma sphere Ge array (Czerwinski et al.,
2013). In addition, they have predicted the Energies of the first 2
+
and 4
+ levels in the 82Zn nucleus using
systematics shown in Figure 1, that presents the calculated excitation
systematics in comparison with the available experimental data (see (Czerwinski
et al., 2013) for more details).


                                                                                                                


Figure 1. Calculated
excitation systematic in comparison with the available experimental data
(Czerwinski et al., 2013).

2. Theoretical framework









One of the most
important phenomena used to study such nuclear systems is the monopole effect; which
has been focused on after the discovering of new nuclei more and more exotic
and the appearance of unexpected observation as the appearance of new magic
numbers, as a result of shell evolution (Cortes and Zuker, 1979; Sorlin and
Porquet, 2008).



This effect comes
from the interactions between the core and the valence nucleons (Otsuka et al.,
2010; Smirnova et al., 2010). In this approximation, a nuclear system can be
presented in terms of a monopole and a multipole Hamiltonians. 

                                                         
(1) 



The monopole part is expressed as a function of single
particle energies
e
s,
occupation
nst, isospin Tst operators, and Vj
which presents an energy average over the spin J (Poves and Zuker,
1981; Otsuka et al.,2010):



                                                              (2)  

The TBMEs of the using interaction are modified taking
in consideration the proton-proton, neutron-neutron and proton-neutron monopole
effects for even-even nuclei in the
78Ni region and a new
interaction is introduced.









3. Results and discussions







For our
calculations, we have used
jj45pn as a single particle state (SPS).
The single particle energies (
SPE) were taken from the experimental data
and from Grawe et al., for some shells (Grawe et al., 2007; nndc.bnl.gov, 2019).
The used interaction is obtained starting from
jj45apn original one,
based on the G matrix for
132Sn region (Jensen et al., 1995;
Rejmund et al., 2016), considering
the monopole effect.



One of the well-known codes, the NuShellX@MSU
is used to carry out the spectroscopic calculations achieved in this work. It
presents a development of
NuShellX code; which contains a set of
computed codes written by Rae (Brown and Rae, 2014). The calculation results in
comparison with the experimental data are reported in Figure 2.




Figure 2. Calculated energetic spectra using jj45apn and jj45am
interactions in comparison with the available experimental data (nndc.bnl.gov,
2019).



These spectra are used to plot the energetic
systematics for
N=52 isotones with Z=30-50. The results are shown
in Figure 3:

Figure 3. Calculated systematics by means of  jj45am
(right) in comparison with the experimental ones (left), in N=52 isotones.



For the
experimental energies (left), the spectra show a peak for Z=38 isotope. The
peak is clear for 4
+, 6+ and 8+ states. The
available data for 2
+ and 4+ states show also a peak for
Z=50. These two peaks are clear in the calculated systematics (right). The peaks
is clear for all excited states.



The explanation of
the Z=50 peak is clear as this charge number is a habitual magic number. The other
peak in Z=38 is a sign of a possible new magic number which can be a result of
shell evolution in
78Ni.



4. Conclusions



This work
is based on the energetic spectra calculations, for even-even N=52 isotones,
with two neutrons and few protons in their valence spaces. The calculations are
realized in the framework of the nuclear shell model, by means of
NuShellX@MSU
nuclear structure code. Using the
jj45apn original interaction of the
code, we carried out some modifications based on the monopole interaction to
get
jj45am one.



Most of the calculated spins and
parities of the studied nuclei are in agreement with the experimental ones. The
excited states calculated using the elaborated interaction
jj45am are
close to the available experimental data, in comparison with those calculated
using the original interaction without monopole terms, which are underestimated
in this case. The calculated results give a prove of the magic nature of the number
Z=38. This may give an important indication of the monopole interaction
consideration role on the explanation of spectroscopic properties.
 



Acknowledgements



Authors of this article thanks to the organizers
of the “XII. International Conference on Nuclear Structure Properties NSP 2019,
October 11
th-13th 2019, Bitlis-Turkey’, for the
organization and the support provided during the conference. Special thanks are
owed to B. A. Brown for his help in providing us theNuShellX@MSU code (Linux
Version).

References

     Dobaczewski, J., Hamamoto, I., Nazarewicz , W., and Sheikh, J. A. 1994. Nuclear Shell Structure at Particle Drip Lines. Physical
Review Letters 72, 981-984.
         Otsuka, T., Suzuki, T., Fujimoto, R., Grawe, H., and Akaishi, Y. 2005. Evolution of Nuclear Shells due to the Tensor Force. Physical
Review Letters 95, 232502 1-4.

    Smirnova, N. A., Bally, B., Heyde, K., Nowacki, F., and Sieja K. 2010. Shell evolution and nuclear forces. Physics Letters B 686,
109-113.

    Cortes, A., and Zuker, A. P. 1979. Self-Consistency and many
body monopole forces in shell model calculations. Physics Letters 84B, 25-30.

     Czerwinski, M. et al. 2013. Yrast excitations in the
neutron-rich N = 52 isotones. Physical Review C 88, 044314 1-13.

    Sorlin, O.,  and Porquet, M. G. 2008. Nuclear Magic numbers: New
features far from stability. Progress in Particle and Nuclear Physics 61,
602-673.

    Otsuka, T., Suzuki, T., Holt, J. D., Schwenk, and A.,
Akaishi, Y. 2010. Three-body forces and the limit of oxygen isotopes. Physical
Review Letters 105, 021501 1-5.

    Poves, A., and Zuker, A. P. 1981. Theoretical spectroscopy
and the FP shell. Physics Reports, 70, 235-314.

    https://www.nndc.bnl.gov/ensdf/endf/xundl.jsp.

    Grawe, H., Langanke, K., and Martinez-Pinedo, G. 2007.
Nuclear structure and astrophysics. Reports on Progress in Physics, 70,
1525-1585.

     Hjorth-Jensen, M., Kuo, T.T.S., Osnes, E. 1995.
Realistic effective interaction for nuclear systems. Physics Reports, 261,
125-270.

      Rejmund, M. et al., 2016. Structural changes at large
angular momentum in nuclear rich
121-123Cd. Physical Review C 93, 024312 1-6,
2016
.

    Brown, B. A., andRae, W.
D. M. 2014. The Shell-Model Code NuShellX@MSU. Nuclear Data Sheets 120,
115-118.




Kaynakça

  • Dobaczewski, J., Hamamoto, I., Nazarewicz , W., Sheikh, J. A., 1994. Nuclear Shell Structure at Particle Drip Lines. Physical Review Letters 72, 981-984.
  • Otsuka, T., Suzuki, T., Fujimoto, R., Grawe, H., Akaishi, Y., 2005. Evolution of Nuclear Shells due to the Tensor Force. Physical Review Letters 95, 232502 1-4.
  • Smirnova, N. A., Bally, B., Heyde, K., Nowacki, F., Sieja K., 2010. Shell evolution and nuclear forces. Physics Letters B 686, 109-113.
  • Cortes, A., Zuker, A. P., 1979. Self-Consistency and many body monopole forces in shell model calculations. Physics Letters 84B, 25-30.
  • Czerwinski, M. et al., 2013. Yrast excitations in the neutron-rich N = 52 isotones. Physical Review C 88, 044314 1-13.
  • Sorlin, O., Porquet, M. G., 2008. Nuclear Magic numbers: New features far from stability. Progress in Particle and Nuclear Physics 61, 602-673.
  • Otsuka, T., Suzuki, T., Holt, J. D., Schwenk, A., Akaishi, Y., 2010. Three-body forces and the limit of oxygen isotopes. Physical Review Letters 105, 021501 1-5.
  • Poves, A., Zuker, A. P., 1981. Theoretical spectroscopy and the FP shell. Physics Reports, 70, 235-314.
  • https://www.nndc.bnl.gov/ensdf/ensdf/xundl.jsp.
  • Grawe, H., Langanke, K., Martinez-Pinedo, G., 2007. Nuclear structure and astrophysics. Reports on Progress in Physics, 70, 1525-1585.
  • Hjorth-Jensen, M., Kuo, T.T.S., Osnes, E., 1995. Realistic effective interaction for nuclear systems. Physics Reports, 261, 125-270.
  • Rejmund, M. et al., 2016. Structural changes at large angular momentum in nuclear rich 121-123Cd. Physical Review C 93, 024312 1-6, 2016.
  • Brown, B. A., Rae, W. D. M., 2014. The Shell-Model Code NuShellX@MSU. Nuclear Data Sheets 120, 115-118.
Yıl 2019, , 109 - 113, 27.12.2019
https://doi.org/10.17678/beuscitech.633561

Öz

Kaynakça

  • Dobaczewski, J., Hamamoto, I., Nazarewicz , W., Sheikh, J. A., 1994. Nuclear Shell Structure at Particle Drip Lines. Physical Review Letters 72, 981-984.
  • Otsuka, T., Suzuki, T., Fujimoto, R., Grawe, H., Akaishi, Y., 2005. Evolution of Nuclear Shells due to the Tensor Force. Physical Review Letters 95, 232502 1-4.
  • Smirnova, N. A., Bally, B., Heyde, K., Nowacki, F., Sieja K., 2010. Shell evolution and nuclear forces. Physics Letters B 686, 109-113.
  • Cortes, A., Zuker, A. P., 1979. Self-Consistency and many body monopole forces in shell model calculations. Physics Letters 84B, 25-30.
  • Czerwinski, M. et al., 2013. Yrast excitations in the neutron-rich N = 52 isotones. Physical Review C 88, 044314 1-13.
  • Sorlin, O., Porquet, M. G., 2008. Nuclear Magic numbers: New features far from stability. Progress in Particle and Nuclear Physics 61, 602-673.
  • Otsuka, T., Suzuki, T., Holt, J. D., Schwenk, A., Akaishi, Y., 2010. Three-body forces and the limit of oxygen isotopes. Physical Review Letters 105, 021501 1-5.
  • Poves, A., Zuker, A. P., 1981. Theoretical spectroscopy and the FP shell. Physics Reports, 70, 235-314.
  • https://www.nndc.bnl.gov/ensdf/ensdf/xundl.jsp.
  • Grawe, H., Langanke, K., Martinez-Pinedo, G., 2007. Nuclear structure and astrophysics. Reports on Progress in Physics, 70, 1525-1585.
  • Hjorth-Jensen, M., Kuo, T.T.S., Osnes, E., 1995. Realistic effective interaction for nuclear systems. Physics Reports, 261, 125-270.
  • Rejmund, M. et al., 2016. Structural changes at large angular momentum in nuclear rich 121-123Cd. Physical Review C 93, 024312 1-6, 2016.
  • Brown, B. A., Rae, W. D. M., 2014. The Shell-Model Code NuShellX@MSU. Nuclear Data Sheets 120, 115-118.
Toplam 13 adet kaynakça vardır.

Ayrıntılar

Birincil Dil İngilizce
Bölüm Makaleler
Yazarlar

Nadjet Laouet

Fatima Benrachı Bu kişi benim

Habiba Guerraıche Bu kişi benim

Karima Benhızıa Bu kişi benim

Yayımlanma Tarihi 27 Aralık 2019
Gönderilme Tarihi 15 Ekim 2019
Yayımlandığı Sayı Yıl 2019

Kaynak Göster

IEEE N. Laouet, F. Benrachı, H. Guerraıche, ve K. Benhızıa, “Study of the Shell Evolution Effect on the Nuclei around the 78Ni Core Structure”, Bitlis Eren University Journal of Science and Technology, c. 9, sy. 2, ss. 109–113, 2019, doi: 10.17678/beuscitech.633561.