L. Rybarcyk

Alpha-burning of O-14

The T=1 analog structure of O-18 and Ne-18 is the basis of the present calculations of the rates for the two alpha-capture reactions O-14(alpha, p)F-17 and O-14(alpha, gamma)Ne-18 in order to determine the influence of the resonant and nonresonant reaction contributions for the T(9) = 0.1-10 temperature range. The possibly significant role of O-14(alpha, p)F-17 as the breakout reaction for the hot CNO cycle is discussed for several H-burning scenarios. 27 references.

Total cross sections for production of7Be,22Na, and24Na inp+7Li andp+27Al reactions at 495 and 795 MeV

Activation techniques have been used to measure the total cross section for the production of {sup 7}Be, {sup 22}Na, and {sup 24}Na in proton induced reactions on {sup 7}Li and {sup 27}Al targets at bombarding energies of 495 MeV and 795 MeV. The cross section for the {sup 7}Li(p,n){sup 7}Be(g.s.+0.43-MeV) reaction at 795 MeV is about 11{endash}15{percent} larger than extrapolations based on previous data below 480 MeV. {copyright} {ital 1997} {ital The American Physical Society}

Uses of radioactive ion beams in astrophysical research

Abstract The radioactive ion beam facility presently being constructed at The Ohio State University is described. Experiments with it will utilize double scattering, the first of which produces the radioactive ion beam of interest, and the second of which produces the reaction of interest. The system is described using the 15 O(α, γ) 19 Ne reaction as an example reaction study. A situation in nuclear burning which involves nuclear isomeric states, that involving the states of 34 Cl, is described, and the considerations required for experimental study of the relevant reactions are given.

RISOAR: A Facility for Production of Beams of Radioactive Ions

A facility to produce beams of low energy radioactive ions such as 7Be, 11C, 13N, 15O and 19Ne is presently under construction at The Ohio State University. The beams, having expected intensities of order 1×106 ions/s and energies of 8 to 16 MeV, will be directed onto a hydrogen or helium gas cell, where the reaction products from proton or ¿-particle radiative capture reactions, or from particle transfer reactions, will be observed. The results of these reaction studies are of interest to fast nucleosynthesis, the mode of stellar burning which takes place in the hot dense stellar environments surrounding an accreting neutron star, or in the region of a supernovae. The present paper describes the general operation of the facility as well as some of the details associated with specific sections of it. Also discussed is a time scale for completion of the project and initiation of the first experiments on it.

Properties and effects on stellar burning of fractionally charged nuclei

The consequences of unconfined quarks which may have been left over from the big bang, especially as to how they might participate in nucleosynthesis, are examined. Possible properties of the fractionally charged nuclei (Q-nuclei) thus produced, including ..beta..-decay half-lives, binding energies, energy level densities, and thermonnuclear reaction rates, are studied. Stellar burning cycles are suggested by these considerations in which the Q-nuclei could contribute significantly to stellar nucleosynthesis, even at an extremely low abundance level, provided that they satisfy some constraints. A model is suggested which accommodates all the constraints thus imposed. Possible implications of the existence of Q-nuclei for stellar evolution are considered, adn the results of a calculation are presented which confirm that no obvious conflicts with the known parameters of the Sun are encountered. The significance of the possible existence of Q-nuclei for future searches for free fractionally charged entities is discussed. Finally, it is noted that any particle which, when added to a nucleus, increases the nucleon binding energy somewhat could perform stellar burning cycles similar to those described in this paper. Subject headings: elementary particles-neutrinos-nuclear reactions:nucleosynthesis-stars: interiors

The effects of Q‐nuclei on stellar burning

The effects of anomalous nuclei, Q‐nuclei, on stellar burning are examined. The baryon binding energies, beta‐decay properties, and thermonuclear reaction rates for the Q‐nuclei suggest they could catalyze a cycle in which four protons are combined to form a 4He nucleus. The properties required of the Q‐nuclei for them to solve the solar neutrino problem are determined. A solar modelling calculation was performed with Q‐nuclei included, and several interesting results therefrom are compared to observations. Finally the solar neutrino detection rates for 71Ga and 115In detectors, in addition to that for 37Cl, are estimated when Q‐nuclei are included in the solar burning.

Total cross sections for production of {sup 7}Be, {sup 22}Na, and {sup 24}Na in p+{sup 7}Li and p+{sup 27}Al reactions at 495 and 795 MeV

Activation techniques have been used to measure the total cross section for the production of {sup 7}Be, {sup 22}Na, and {sup 24}Na in proton induced reactions on {sup 7}Li and {sup 27}Al targets at bombarding energies of 495 MeV and 795 MeV. The cross section for the {sup 7}Li(p,n){sup 7}Be(g.s.+0.43-MeV) reaction at 795 MeV is about 11{endash}15{percent} larger than extrapolations based on previous data below 480 MeV. {copyright} {ital 1997} {ital The American Physical Society}

Total cross sections for production of Be-7, Na-22, and Na-24 in p+ Li-7 and p+ Al-27 reactions at 495 and 795 MeV

Activation techniques have been used to measure the total cross section for the production of {sup 7}Be, {sup 22}Na, and {sup 24}Na in proton induced reactions on {sup 7}Li and {sup 27}Al targets at bombarding energies of 495 MeV and 795 MeV. The cross section for the {sup 7}Li(p,n){sup 7}Be(g.s.+0.43-MeV) reaction at 795 MeV is about 11{endash}15{percent} larger than extrapolations based on previous data below 480 MeV. {copyright} {ital 1997} {ital The American Physical Society}