The 8Be Ground State Formation in 6O(γ,4α) - Reaction

Keywords: diffusion chamber, photodisintegration, excitation energy, quasiberyllium


The reaction 16O(γ,4α) was studied with the aid of a diffusion chamber placed in a magnetic field in the energy range Еγ < 40 MeV. The ground of the 8Be nucleus manifested in the distribution of events with respect to the excitation energy of two alpha particles. A particle was identified as α3 and α4. The partial cross section for the channel formation ground state 8Be was measured versus the photon energy. Fourth resonances have been observed in the cross section. The energy corresponding to the ith maximum of the partial cross section and the excitation energy of the ith level of the 8Be nucleus have been found to be correlated as Еγi(16О) = E0i(8Be) + ε(16О), where ε(16О) is the reaction 16О(γ,4α) threshold. Qualitatively, the results have been explained on the basis of the model of photon absorption by a quasiberyllium. At the analysis of distributions on kinetic energy of a‑particles it is certain, that a1‑particle escapes from the 12C nucleus, while the remaining α2‑particles with α3‑ and α4‑particles form an excited nucleus 12C.


Download data is not yet available.


Funaki Y., Yamada T., Horiuchi H., et al. -particles condensation in 16O studied with a full four-body orthogonality comdition model calculation // Phys. Rev. Lett. – 2008. – Vol. 101. – 082502 [4 pages].

Coc A., Angulo C., Vangioni-Flam E., et al. Big Bang nucleosynthesis, microwave anisotropy, and the light element abundances // Nucl. Phys. A. – 2005. – Vol. 752. – P. 522-531.

Thielemann F.-K., Brachwitz F., Freiburghaus C., et al. Element synthesis in stars // Prog. Part. Nucl. Phys. – 2001. – Vol. 46. – P. 5-22.

Goward F.K. Multiple resonance in photodisintegration cross sections // Proc. Phys. Soc. A. – 1952. – Vol. 65. – P. 671-672.

Millar C.H. Photo-alpha reactions in nuclear emulsions // Can. J. Phys. – 1953. – Vol. 31. – P. 723—757.

Toms M.E. Photoalpha reactions below 21.5 MeV with 14N and 16O // Nucl. Phys. – 1964. – Vol. 54. – P. 625-640.

Голубев Р.А., Кириченко В.В., Лапин Н.И. и др. Методика обработки экспериментальных данных по реакциям многочастичного фоторасщепления легчайших ядер 12С и 16О // Препринт ННЦ ХФТИ. – 1992. – №92-36. – С. 1-14.

Аркатов Ю.М., Вацет П.И., Волощук В.И. и др. Установка для изучения фотоядерных реакций // ПТЭ. – 1969. – №3. – C. 205.

Аркатов Ю.М., Вацет П.И., Волощук В.И. и др. Метод обработки стереофотографий с диффузионной камеры // Харьков: Препринт ХФТИ АН УССР. – № 70-37. – 1970. – 24 С.

Балдин А.М., Гольданский В.И., Максименко В.М., Розенталь И.Л. Кинематика ядерных реакций // М.: Атомиздат. – 1968. – 456 c.

Tilley D.R., Kelley J.H., Godwin J.L., et al. Energy levels of light nuclei A = 8, 9, 10 // Nucl. Phys. A. – 2004. – Vol. 745. – P. 155—362.

Афанасьев С.Н., Ходячих А.Ф. О механизме образования возбужденных состояний ядра 8Ве в реакции 12С(γ,3α) // Ядерная Физика. – 2008. – Т. 71, №11. – С. 1859—1869.

Ajzenberg-Selove F. Energy levels of light nuclei A=11-12 // Nucl. Phys. A. – 1990. – Vol. 506. – P. 1-158.

How to Cite
Afanas’ev, S. (2012). The 8Be Ground State Formation in 6O(γ,4α) - Reaction. East European Journal of Physics, (1025(4), 4-9. Retrieved from