Nuclear astrophysics from neutron cross-section measurements on radioactive samples

doi:10.1016/0168-583X(89)91029-X

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

Volumes 40–41, Part 1, 2 April 1989, Pages 494-497

https://doi.org/10.1016/0168-583X(89)91029-X Get rights and content

Abstract

Reaction rates for both big-bang and stellar nucleosynthesis calculations can be obtained from the measurement of (n, p) (n, α) and (n, γ) cross sections for radioactive nuclei. In the past, large backgrounds associated with the sample activity limited these types of measurements to radioisotopes with very long half-lives. The advent of the high-intensity neutron source at the Los Alamos Neutron Scattering CEnter (LANSCE) has greatly increased the number of nuclei which can be studied. Results of recent measurements on samples with half-lives as short as 53 days are given. Plans for future measurements are discussed.

References (32)

S.E. Woosley
Atom. Data Nucl. Data Tables
(1978)
A. Emsallem
Nucl. Phys.
(1981)
H. Weigmann
Nucl. Phys.
(1981)
Yu.M. Popov
Z. Phys.
(1985)
P.E. Koehler
Phys. Rev.
(1988)
P.E. Koehler et al.
W.M. Howard
Astrophys. J.
(1972)
P. Delbourgo-Salvador et al.
Astron. Astrophys.
(1985)
K. Brehm
Z. Phys.
(1988)
H.P. Trautvetter
Z. Phys.
(1986)
R.N. Silver
Physica
(1986)

P.E. Koehler et al.

Phys. Rev.

(1988)

P.E. Koehler et al.

J.A. Halbheb et al.

CYLTRAN, Sandia National Laboratories Report, SAND 74-0030

(1974)

H.H. Hsu

IEEE Trans. Nucl. Sci.

(1984)

K. Wisshak et al.

Nucl. Instr. and Meth.

(1984)

K. Wisshak et al.

Nucl. Instr. and Meth.

(1984)

G.J. MathewsG.J. Mathews

Cited by (12)

Energy levels of light nuclei A = 18-19
1995, Nuclear Physics, Section A
Radioactive targets for nuclear astrophysics research at LANSCE
1991, Nuclear Inst. and Methods in Physics Research, A
During the past few years we have made measurements of (n, p) and (n, α) cross sections on several radioactive nuclei of importance to nuclear astrophysics. The measurements were made at the Manuel Lujan, Jr. Neutron Scattering Center (LANSCE) from thermal neutron energy to approximately 100 keV. Successful measurements have been completed on the radioisotopes ⁷Be, ²²Na and ³⁶Cl while preliminary data have been taken on targets of ⁵⁴Mn and ⁵⁵Fe. Similar measurements have also been made on the stable isotopes ¹⁴N, ¹⁷O and ³⁵Cl. We are currently assembling a 4π barium fluoride (BaF₂) detector which will allow us to expand our program to (n, γ) measurements. The (n, γ) (and in some cases future (n, p)) measurements will require targets with higher specific activity and greater chemical purity than we have so far been able to use. We discuss the fabrication techniques used for the samples produced so far, the requirements the future (n, γ) targets must meet and our current plans for producing them, and the physics motivations for the measurements.
Energy levels of A = 21-44 nuclei (VII)
1990, Nuclear Physics, Section A
The experimentally determined properties of A = 21–44 nuclides are complied and evaluated with special emphasis on nuclear spectroscopy.
Separate tables for each of the nuclides reviewed present the available information about the following properties (in this order):
- •
  - excitation energies E_x,
- •
  - γ-ray branching ratios b(γ),
- •
  - γ-ray mixing ratios σ,
- •
  - lifetimes γ_m or widths Λ,
- •
  - neutron, proton, or α-particle resonances,
- •
  - partial widths,
- •
  - single-nucleon transfer reactions,
- •
  - beta-decay,
- •
  - arguments for spin and parity (J^π) and isospin (T) assignments.
For each nuclide a master table summarizing the “best” or adopted values for E_x, J^π; T and τ_m or Λ precedes the auxiliary tables listed above.
The review of each A-chain concludes with a discussion of isospin multiplets.
Figures are presented of the level schemes of all nuclei and, for each A-chain, an overview of the relative energies of the ground states and lowest analogue states of all nuclei in the chain.
Measurement of the LANSCE neutron flux from 0.025 eV to 100 keV
1990, Nuclear Inst. and Methods in Physics Research, A
Effect of Backing on Neutron Spectra for Low Energy Quasi-Mono-energetic p+<sup>7</sup>Li Reaction.
2023, arXiv
Neutron resonance parameters for Be-7 (Beryllium)
2015, Neutron Resonance Parameters

View all citing articles on Scopus

View full text

Section III. Nuclear physics and astrophysicsNuclear astrophysics from neutron cross-section measurements on radioactive samples

Abstract

Atom. Data Nucl. Data Tables

Nucl. Phys.

Nucl. Phys.

Z. Phys.

Phys. Rev.

Astrophys. J.

Astron. Astrophys.

Z. Phys.

Z. Phys.

Physica

Phys. Rev.

CYLTRAN, Sandia National Laboratories Report, SAND 74-0030

IEEE Trans. Nucl. Sci.

Nucl. Instr. and Meth.

Nucl. Instr. and Meth.

Section III. Nuclear physics and astrophysics
Nuclear astrophysics from neutron cross-section measurements on radioactive samples