# Effect of Exciton Number on One – Component and Two – Component Partial Level Density Formulae

## Authors

• Suha Ali Najm Department of Physics, College of Science for Women, University of Baghdad, Baghdad, Iraq. https://orcid.org/0009-0002-7001-4291
• Ali Dawoud Salloum Department of Physics, College of Science for Women, University of Baghdad, Baghdad, Iraq.

## Keywords:

Level Density, Nuclear Level Density, Nuclear Reaction, Pre-Compound Nucleus, Pre-Equilibrium

## Abstract

In this paper we made a comparison between the theoretical results of one and two components of partial level density Ericson's formulae with the experimental results. In the frame work of equidistant spacing model. It is noticed that the values of one - component partial level density formula increases with increasing the exciton number. the excitons numbers is taken 3, 5, 7 and 9. The same excitons number is substituted in two-component partial level density formula, but the increase in partial level density values in case of two components with the excitons numbers is slight and this change is so small that it cannot be seen. Therefore one can say that the increase in exciton number effects on the one-component partial level density value and lead to an increase them. But in the case of two-components the partial level density value doesn't affect by the change in exciton number values because the energy distributed on particles more than in case of one- component and this makes partial level density less than in case of one-component and the effect of change in exciton number doesn't appear. In case of one-component when the exciton numbers is n=3 the theoretical partial level density curve lies below the experimental curve and when n=5 the theoretical curve become more close to the experimental curve. And at n = 7 the theoretical curve intersect with the experimental curve at E = 5 MeV, So when n=9 the theoretical curve intersect with the experimental curve at 4 MeV.

## References

Rahmatinejad A, Bezbakh AN. Level density parameters of heaviest nuclei. Acta Phys. Pol. 2021,13(3):491-498. https://doi.org/10.5506/APhysPolBSupp.13.491.

Magner AG, Sanzhur AI, Fedotkin SN, Levon AI and Shlomo S. Level density with micro-macroscopic approach. Nucl. Phys. A. 2022,1021.1-10. https://doi.org/10.1016/j.nuclphysa.2022.122423

Pahlavani MR and Dinan MM. Thermal properties of 172Yb and 162Dy isotopes in the back-shifted Fermi gas model with temperature-dependent pairing energy.J.Phys.2019,93:1-10. https://doi.org/10.1007/s12043-019-1799-y.

Mohanto G, Rout PC, Raimachandran K, Mirgule ET,Srinivasan B, Kundu A et al. Probing collective enhancement in nuclear level density with evaporation α particle spectra. Phys.Rev.2022,105(3):1-6. https://doi.org/10.1103/PhysRevC.105.034607.

Alwan T A, Hamed B S. Study the Nuclear Structure of Some Even-Even Ca Isotopes Using the Microscopic Theory. Baghdad Sci J. Feb 2023;20(1):505-508. https://doi.org//10.21123/bsj.2022.6924.

Mamun Md A. Thermal Properties of Nuclei and Their Level Densities. Ohio: Ohio university; 2015.

Bucurescu D, Egidy T. Systematic of nuclear level density parameters. Phys Rev C. Oct 2005; 72(4): 44311:1-22. https://doi.org/10.1088/0954-3899/31/10/052.

Rahmatinejad A, Bezbakh A N, Shneidman T M, Adamian G, Antonenko N V, Jachimowicz P, et al. Level-density parameters in super heavy nuclei. Phys Rev C. March 2021; 103(3): 1-10. https://doi.org/10.1103/PhysRevC.103.034309.

Roy P, Mukhopadhyay S, Aggarwal M, Pandit D, Rana T K, Kundu S, et al. Excitation energy and angular momentum dependence of the nuclear level density parameter around A=110. PhyRev.2021,103(2):24602:1-9. https://doi.org/10.1103/PhysRevC.103.024602.

Abdulla A M, Salloum A D. A Comparison Between the Theoretical Cross Section Based on the Partial Level Density Formulae Calculated by the Exciton Model with the Experimental Data for (_79^197)Au nucleus, December . Baghdad SciJ.2021;18(1):139-143. https://doi.org/10.21123/bsj.2021.18.1.0139.