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Some Calculated (p,α) Cross-Sections Using the Alpha Particle Knock-On and Triton Pick-Up Reaction Mechanisms: An Optimisation of the Single-Step Feshbache-Kermane-Koonin (FKK) Theory

  • Olise, Felix S. (Department of Physics and Engineering Physics, Obafemi Awolowo University) ;
  • Ajala, Afis (Department of Physics and Engineering Physics, Obafemi Awolowo University) ;
  • Olaniyi, Hezekiah B. (Department of Physics and Engineering Physics, Obafemi Awolowo University)
  • Received : 2015.09.22
  • Accepted : 2015.11.17
  • Published : 2016.04.25

Abstract

The Feshbache-Kermane-Koonin (FKK) multi-step direct (MSD) theory of pre-equilibrium reactions has been used to compute the single-step cross-sections for some (p,${\alpha}$) reactions using the knock-on and pick-up reaction mechanisms at two incident proton energies. For the knock-on mechanism, the reaction was assumed to have taken place by the direct ejection of a preformed alpha cluster in a shell-model state of the target. But the reaction was assumed to have taken place by the pick-up of a preformed triton cluster (also bound in a shell-model state of the target core) by the incident proton for the pick-up mechanism. The Yukawa forms of potential were used for the proton-alpha (for the knock-on process) and proton-triton (for the pick-up process) interaction and several parameter sets for the proton and alpha-particle optical potentials. The calculated cross-sections for both mechanisms gave satisfactory fits to the experimental data. Furthermore, it has been shown that some combinations of the calculated distorted wave Born approximation cross-sections for the two reaction mechanisms in the FKK MSD theory are able to give better fits to the experimental data, especially in terms of range of agreement. In addition, the theory has been observed to be valid over a wider range of energy.

Keywords

References

  1. H. Feshbach, A. Kerman, S. Koonin, The statistical theory of multi-step compound and direct reactions, Ann. Phys. 125 (1980) 429-476. https://doi.org/10.1016/0003-4916(80)90140-2
  2. R. Bonetti, M.B. Chadwick, P.E. Hodgson, B.V. Carlson, M.S. Hussein, The Feshback-Kerman-Koonin multistep compound reaction theory, Phys. Rep. 202 (1991) 171-231. https://doi.org/10.1016/0370-1573(91)90105-U
  3. R. Bonetti, A.J. Koning, J.M. Akkermans, P.E. Hodgson, The Feshback-Kerman-Koonin multistep compound reaction theory, Phys. Rep. 247 (1994) 1-58. https://doi.org/10.1016/0370-1573(94)90153-8
  4. E. Gadioli, P.E. Hodson, Pre-Equilibrium Nuclear Reactions, Oxford University Press, 1992, ISBN 0-19-851734-3.
  5. O. Dragun, A.M. Ferrero,A. Pacheco, Pickupmechanismin (p, ${\alpha}$) pre-equilibrium reactions, Nucl. Phys. A 369 (1981) 149-165. https://doi.org/10.1016/0375-9474(81)90012-9
  6. H.B. Olaniyi, P. Demetriou, P.E. Hodgson, Analysis of the (p, ${\alpha}$) reaction using the pre-equilibrium multi-step direct Feshback-Kerman-Koonin theory, J. Phys. G: Nucl. Part. Phys. 21 (1995) 361-375. https://doi.org/10.1088/0954-3899/21/3/011
  7. A.A. Cowley, G.J. Arendse, J.W. Koen, W.A. Richter, J.A. Stander, Inclusive (p, ${\alpha}$) reactions on $^{27}$Al, $^{59}$Co, and $^{197}$Au at incident energies of 120, 160 and 200 MeV, Phys. Rev. C 54(1996) 778-783. https://doi.org/10.1103/PhysRevC.54.778
  8. P. Demetriou, P.E. Hodgson, A. Marcinkowski, Y. Watanabe, The energy dependence of the proton-alpha reaction to continuum states, J. Phys. G: Nucl. Part. Phys. 22 (1996) 629-640. https://doi.org/10.1088/0954-3899/22/5/010
  9. A.A. Cowley, G.F. Steyn, S.S. Dimitrova, P.E. Hodgson, G.J. Arendse, S.V. Fortsch, G.C. Hillhouse, J.J. Lawrie, R. Noveling, W.A. Richter, J.A. Stander, S.M. Wyngaardt, Multistep direct mechanism in the (p${\rightarrow}$, $^3$He) inclusive reaction on $^{59}$Co and $^{93}$Nb at an incident energy of 100 MeV, Phys. Rev. C 62 (2000) 460-465.
  10. A. Ajala, Unpublished (PREX: A Single-step Knock-out and Pick-up MSD Code), 2012 [Internet]. Available from: http://www.oauife.edu.ng/library.
  11. A.M. Ferrero, E. Gadioli, E. Gadioli-Erba, I. Iori, N. Molho, L. Zetta, ${\alpha}$ emission in proton induced reactions, Z. Phys. A 293 (1979) 123-134. https://doi.org/10.1007/BF01559754
  12. P.E. Hodgson, Pre-equilibrium processes in nuclear reactions, Lect. Notes Phys. 168 (1982) 220-247.
  13. T. Ericson, The statistical model and nuclear level densities, Adv. Phys. 9 (1960) 425-511. https://doi.org/10.1080/00018736000101239
  14. A. Marcinkowski, P. Demetriou, P.E. Hodgson, Are pre-quilibrium reactions mainly direct? J. Phys. G: Nucl. Part. Phys. 21 (1995) 1089-1099. https://doi.org/10.1088/0954-3899/21/8/007
  15. H. Gruppelaar, 'IAEA Advisory Group Meeting on Basic and Applied Problems on Nuclear Level Densities', 1983.
  16. P.D. Kunz, DWBA Code DWUCK4, 1973 [Internet]. [2012 Mar 8]. Available from: http://spot.colorado.edu/-kunz/DWBA.html.
  17. M. Ichimura, A. Arima, E.C. Halbert, T. Terasawa, Alpha particle spectroscopic amplitudes and the su(3) model, Nucl. Phys. A 204 (1973) 225-278. https://doi.org/10.1016/0375-9474(73)90272-8
  18. P.D. Kunz, Documention for the Use of DWUCK4, 1997 [Internet]. [2012 Mar 8]. Available from: http://spot.colorado.edu/-kunz/DWBA.html.
  19. L. Milazzo-Colli, G.M. Braga-Marcazzan, Pre-equilibrium emission in (n, p) and (n, ${\alpha}$) reactions on CsI, Phys. Lett. B 36 (1971) 447-450.
  20. L. Milazzo-Colli, G.M. Braga-Marcazzan, The preformation of ${\alpha}$ particles in heavy nuclei by the analysis of (n, ${\alpha}$) reactions, Phys. Lett. B 38 (1972) 155-158.
  21. G.M. Braga-Marcazzan, L. Milazzo-Colli, C. Signorini, Pre-equilibrium ${\alpha}$-particle emission in the $^{115}$In(p, ${\alpha}$)$^{112}$Cd, Lett. Nuovo Cimento Ser. 2 6 (1973) 357-361.
  22. M. Hillman, J.R. Grover, Shell-model combinatorial calculations of nuclear level densities, Nucl. Phys. A 185 (1969) 1303-1319.
  23. F.D. Bechetti, G.W. Greenlees, Nucleon-nucleous optical potentials for emitted alpha particles, Phys. Rev. 182 (1969) 1190-1209. https://doi.org/10.1103/PhysRev.182.1190
  24. V. Avrigeanu, M. Avrigeanu, P.E. Hodgson, Global optical potentials for emitted alpha particles, Phys. Rev. C 49 (1994) 2136-2141. https://doi.org/10.1103/PhysRevC.49.2136
  25. P. Demetriou, P. Kanjanarat, P.E. Hodgson, Analysis of the multistep direct component of 14 MeV neutron inelastic scattering, J. Phys. G 19 (1993) 193-198. https://doi.org/10.1088/0954-3899/19/12/003
  26. T. Tamura, T. Udagawa, Multi-step-direct reaction analysis of continuum spectra of (p, ${\alpha}$) reaction, Phys. Lett. B 82 (1977) 273-275.
  27. T. Tamura, T. Udagawa, H. Lenske, Multistep direct reactionanalysis of continuum spectra induced by light ions, Phys. Rev. C 26 (1982) 379-404.
  28. F.E. Bertrand, R.W. Peelle, Technical Report Report ORNL-4460 Oak Ridge, 1970.
  29. F.E. Bertrand, R.W. Peelle, Technical Report Report ORNL-4471 Oak Ridge, 1970.
  30. H.B. Olaniyi, P. Kanjanarat, P.E. Hodgson, Multistep compound reaction calculations using the Feshback-Kerman-Koonin Theory, J. Phys. G: Nucl. Part. Phys. 19 (1993) 1029-1036. https://doi.org/10.1088/0954-3899/19/7/013
  31. P. Demetriou, P. Kanjanarat, P.E. Hodgson, FKK analysis of 14 MeV neutron-induced reactions, J. Phys. G: Nucl. Part. Phys. 20 (1994) 1779-1788. https://doi.org/10.1088/0954-3899/20/11/007
  32. A.J. Koning, J.M. Akkermans, Randomness in multi-step direct reactions, Ann. Phys. 208 (1991) 216-250. https://doi.org/10.1016/0003-4916(91)90345-9
  33. R. Bonetti, F. Crespi, K.I. Kubo, The 58Ni(p, ${\alpha}$) reaction mechanism through a study of the analyzing power, Nucl. Phys. A 499 (1989) 381-391. https://doi.org/10.1016/0375-9474(89)90053-5