NEW RESULTS FOR RADIATIVE P-11B CAPTURE AT LOW ENERGIES

The results of new measurements of the yields of the 11B(p,γ)12C reaction of radiative capture to the ground and first excited states of 12C are presented. By normalizing these results to the corresponding experimental literature data, differential cross sections have been extracted for the angle 0° and for incident proton energies from 482 to 1337 keV. Based on the obtained differential cross sections and using literature data on the angular distributions of the 11B(p,γ)12C reaction in this energy region, the total cross sections and astrophysical S factors of the 11B(p,γ)12C reaction for transitions to the ground and first excited states of 12C have been determined with a statistical error of less than 10%. The experimental data obtained are well described within the framework of a modified potential cluster model with the classification of orbital states according to Young's diagrams and taking into account allowed and forbidden states. Based on the measured experimental cross sections and using the above theoretical model, the rate of this reaction was calculated in the temperature range from 0 to 100 million degrees of Kelvin. Within the limits of error, the results of this work are consistent with the data of earlier works.

1. C.A. Barnes, D.D. Clayton, and D.N. Schramm. Essays in nuclear astrophysics. Presented to William A. Fowler, on the occasion of his seventieth birthday, (Cambridge University Press, Cambridge), 562 P. (1982); S.B. Dubovichenko. Thermonuclear processes in Stars and Universe. Second English Edition, revised and expanded, (Saarbrucken, Germany, Scholar’s Press), 332 P. (2015); D.D. Clayton. Principles of Stellar Evolution and Nucleo- synthesis, (University of Chicago Press, Chicago), 634 P. (1983); D.N. Schramm and R. Wagoner, Annu. Rev. Nucl. Sci. 27, 37 (1977).

2. R.E. Segel, S.S. Hanna, R.G. Allas // Phys. Rev. – Vol. 139. – P. B818–B830 (1965).

3. A.A. Arzumanov, Proceedings of the 13th particle accele- rator conference. Dubna, Russia, October 13-15, 1, 118 (1992).

4. J.W. Butler // U.S. Naval Research Laboratory, NRL Report, 5282 (1959).

5. P.B. Lyons, J.W. Toevs and D.G. Sargood // Nucl. Phys. A130, 1 (1969).

6. N. Burtebaev, S.B. Igamov, R.J. Peterson, R. Yarmukha- medov and D.M. Zazulin // Phys. Rev. C78. – P. 035802. (2008).

7. J.H. Kelley, J.E. Purcell, C.G. Sheu. Energy levels of light nuclei A = 12. Nuclear Physics A968, 71-253 (2017).

8. S.B. Dubovichenko, N. Burtebaev, D.M. Zazulin, Zh.K. Kerimkulov and A.S.A. Amar // Phys. Atom. Nucl.. – Vol. 74. – P. 984. (2011).

9. Sergey Dubovichenko, Nassurlla Burtebayev, Albert Dzhazairov-Kakhramanov, Denis Zazulin, Zhambul Kerimkulov, Marzhan Nassurlla, Chingis Omarov, Alesya Tkachenko, Tatyana Shmygaleva, Stanislaw Kliczewski, Turlan Sadykov // Chinese Physics C41. – P. 014001. (2017).

10. P.H. Barker and R.D. Connor // Nucl. Inst. And Meth. – Vol. 57. – P. 147 (1967).

11. A. Anttila, J. Keinonen, M. Hautala, I. Forsblom. Use of the 27Al(p,γ)28Si, Ep = 992 keV resonance as a gamma- ray intensity standard // Nucl. Instr. Meth. – Vol.147. – P. 501–505. (1977).

12. J.J. He et.al. Direct measurement of 11B(p,γ)12C astro- physical S-factor at low energies // Physical Review C – V. 93. 5. – P. 055804. (2016).

13. http://lise.nscl.msu.edu/lise.html

14. Y. Xu, K. Takahashi, S. Goriely, M. Arnould, M. Ohta, H. Utsunomiya. NACRE II: an update of the NACRE compi- lation of charged-particle-induced thermonuclear reaction rates for nuclei with mass number A < 16 // Nucl. Phys. A. – V. 918. – P.61–169. (2013).

15. S.B. Dubovichenko Astrophysical proton capture by 11B nucleus // Russian Physics Journal. – V. 58 1. – P. 17–25. (2015).

16. V.G. Neudatchin, V.I. Kukulin, V.N. Pomerantsev, A.A. Sakharuk Generalized potential model description of mutual scattering of the lightest p+d, d+3He nuclei and the corresponding photonuclear reactions // Physical Review C. – V. 45. – P. 1512–1527. (1992).

17. S.B. Dubovichenko, A.V. Dzhazairov-Kakhramanov, N.A. Burkova Neutron radiative capture by 2H, 6Li, 7Li, 12C and 13C at astrophysical energies // International Journal of Modern Physics E. – V. 22. – No. 5. – P. 1350028-1–1350028-52. (2013).

18. S.B. Dubovichenko, A.S. Tkachenko, R.Ya. Kezerashvili, N.A. Burkova, and A.V. Dzhazairov-Kakhramanov. 6Li(p,γ)7Be reaction rate in the light of the new data of the Laboratory for Underground Nuclear Astrophysics // Physical Review C. – V. 105. – P. 065806. (2022).

19. S.B. Dubovichenko, N.A.Burkova, A.S.Tkachenko, A.V.Dzhazairov-Kakhramanov. Influence of resonances on the 11B(n,γ)12B reaction rate. Capture at excited states of 12B // International Journal of Modern Physics E – V. 32. – No. 2. – P. 2350008-1–2350008-39. (2023).

20. J.H. Kelley, R.S. Canon, S.J. Gaff, R.M. Prior, B.J. Rice, E.C. Schreiber, M. Spraker, D.R. Tilley, E.A. Wulf, and H.R. Weller The 11B(p,γ)12C reaction below 100 keV // Physical Review C. – V. 62. – P. 025803-1–025803-1. (2000).

21. T. Huus, R.B. Day. The gamma radiation from 11B bom- barded by protons // Physical Review. – V. 91. –P. 599– 605. (1953).

22. R.G. Allas, S.S. Hanna, Luise Meyer-Schützmeister, R.E. Segel. Radiative capture of protons by 11B and the giant dipole resonance in 12C // Nuclear Physics. – V. 58. – P. 122–144. (1964).

23. S.O. Nelson, E.A. Wulf, J.H. Kelley, H.R. Weller Evalua- tions of thermonuclear proton capture reaction rates for 2H, 7Li, 9Be, and 11B // Nuclear Physics A. – V. 679. – P. 199–211. (2000).