Competition cusps in (α, γ) reactions

doi:10.1016/0375-9474(79)90308-7

Nuclear Physics A

Volume 331, Issue 1, 19 November 1979, Pages 180-192

https://doi.org/10.1016/0375-9474(79)90308-7 Get rights and content

Abstract

Absolute cross sections are presented for the reactions ³⁷Cl(α, γ)⁴¹K for 2.90 MeV ≦ E^lab_α ≦ 5.23 MeV, $^{62} Ni (α, γ)^{66} Zn for 5.07 MeV ≦ E_{α}^{−2} lab ≦ 8.64 MeV,^{62} Ni (α, n)^{65} Zn$ for energies near the (α, n₀) threshold at $E_{α}^{lab} = 6.90 MeV up to 8.76 MeV,^{64} Ni (α, γ)^{68} Zn for 4.50 ≦ E_{α}^{lab} ≦ 7.45 MeV$ , and for ⁶⁴Ni(α, n)⁶⁷N from E_α^lab = 5.30 MeV up to E_α = 7.45 MeV. Substantial competition cusps were observed in the excitation function for all three (α, γ) reactions. The data were found to be in reasonable agreement with the predictions of the current versions of global Hauser-Feshbach models used in nucleosynthesis calculations. Including width fluctuation corrections and realistic neutron strength functions generally improves the ability of the models to predict the depth of the (α, γ) competition cusps; the depths of the predicted (α,γ) cusps are insensitive to the degree of isospin mixing. Taken together with studies of competition effects in proton-induced reactions, the present data confirm the importance of width fluctuation and strength function effects, and indicate essentially complete isospin mixing between T^< and T ^> states in the compound nucleus.

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^☆: Supported in part by the National Science Foundation [PHY76-83685].

^‡: Permanent address: Physics Department, California State University, Fullerton, CA 92634.

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Competition cusps in (α, γ) reactions☆

Abstract

Phys. Lett.

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Atomic Data and Nucl. Data Tables

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Atomic Data and Nucl. Data Tables

Hanford Engineering Department Laboratory Report, HEDL-TME-76-80