[en] This report gives a brief summary of accomplishments made on this project. Approximately 22 refereed papers were published with support from this grant; reprints are attached with this report. Topics studied include amplitude distributions in proton resonance reactions, chaos in nuclei, and tests of detailed balance and of parity violation with resonance reactions. Appendix 1 lists personnel and collaborators associated with this work, including the undergraduate students hired with grant funds, while Appendix 2 provides a list of talks, abstracts, dissertations and theses, etc. associated with the work supported by this grant

[en] This report discusses the following topics: Complete Level Scheme for ³⁰P; A Search for Resonances Suitable for Tests of Detailed-Balance Violation; The Fourier Transform as a Tool for Detecting Chaos; Entrance Channel Correlations in p + ²⁷Al; The Parity Dependence of Level Densities in ⁴⁹V; and A Computer Program for the Calculation of Angular Momentum Coupling

[en] Preparations for studying ³⁰P via ²⁹Si(p,γ) have continued. We are exploring both the use of the Fourier transform and the statistical behavior of electromagnetic transition strengths within the shell model as alternate approaches to identifying quantum chaos in nuclei. Analysis of interfering resonances in (p,α) resonances suggests that improvements in the limits on detailed balance in nuclear reactions are possible, but several issues still must be considered before a definitive conclusion can be reached. Plans for a new control system for the High Resolution Laboratory's electrostatic analyzer are being implemented

[en] This report summarizes the progress on Grant No. FG05-87ER40353 during the period February 1, 1990 to November 30, 1990. The primary focus of the research during this period has been on fluctuations of nuclear levels and possible connections with fundamental symmetries. In this paper the analysis of low-lying nuclear levels for a large collection of nuclides is discussed, and the analysis of just the levels in ¹¹⁶Sn is presented. The current status experiments to study fluctuation properties in ³⁰P is summarized, while the development of hardware and software for the next phase of these measurements in outlined. We discuss the early stages of a project to search for a particular type of detailed-balance violation

[en] Resonances in nuclei have provided the major testing ground for random-matrix theory. With the recent demonstration that certain quantum chaotic systems also appear to be described by random-matrix theory, the possibility that the nucleus is itself a quantum chaotic system has been suggested. Although showing no direct relation to quantum chaos, some of the work described herein has examined more closely the role of a random-matrix description of nuclei. We have shown that the body of resonance amplitude data shows overall agreement with the key prediction of random-matrix theory that the amplitudes should obey a Gaussian distribution. We also have new data which for the first time show correlations between entrance channels. The role of energy level fluctuations in ²⁶Al is being examined to see if random-matrix theory can provide a good description at energies near the ground state. We also hope to learn something about the role of isospin symmetry in this nucleus by analyzing fluctuations of the T = 0 and T = 1 levels separately. The role of spectroscopy of individual levels in studying symmetries has also been investigated. An attempt to populate the lowest isospin 2 state in ⁴⁰Ca via the isospin-forbidden p + ³⁹K reaction has been made. Finally, detailed calculations on the role of nuclear spectroscopy in experiments to measure parity mixing in slow neutron resonances have been performed; these calculations reveal the necessity of a thorough understanding of the spectroscopy of the states involved in order to extract the parity-nonconserving matrix element. 29 refs

[en] Work on chaos in the low-lying levels of nuclei has continued on several fronts. The major effort has been study of the ²⁹Si(p,γ) reaction with the goal of establishing a complete level scheme for ³⁰P and analyzing the eigenvalue fluctuations for evidence of chaos. These measurements are in progress, and the current status is described. A related topic is the search for different signatures of chaos which do not require the extremely high degree of completeness and purity necessary for eigenvalue analyses; those efforts are discussed in Sections 2 and 3. The possibility of studying both parity violation and time-reversal invariance violation with charged particle resonances has been explored by performing calculations using experimentally measured resonance parameters. Large enhancements are indeed available; the results are discussed in Sections 4 and 5. Preparations for an experimental study of parity violation using these techniques are ongoing. An undergraduate project searching for experimental evidence of a parity dependence of level density is discussed in Section 6. A number of improvements to the operation of the TUNL KN accelerator have been implemented in the past three years. These are described in Section 7

[en] This paper discusses the following topics: fluctuation properties of energy levels in ²⁶Al; fluctuation properties of low-lying nuclear states; energy levels in ³⁰P; entrance channel correlations in ⁴⁰Ca; and entrance channel correlations in ²⁸Si

[en] Work on chaos in low-energy nuclear systems has continued on several fronts. The authors have completed the preparatory stage for their experiments to establish a complete level scheme in ³⁰P, and the first data were taken in December. As an alternative approach to chaos, they are studying suggestions that the transition strengths can be used as an appropriate signature. The first studies are using shell-model calculations for ²²Na; a sufficient number of B(E1) and B(M2) values have been calculated that the statistical errors are not the primary limiting factor. They will refine their analysis techniques on this set and then analyze experimental data from ²⁶Al. Details are given in Sects. 1 and 4. They have also continued to study the possibilities of studying both detailed-balance violation and parity violation with charged-particle resonances. They have calculated expected enhancements for a large number of potentially interfering resonances; the results are described in Sects. 2 and 3. They have replaced several control systems in the TUNL High Resolution Laboratory in the past year. Both the electrostatic analyzer and the analyzing magnet are now controlled via a 80486 PC running the software package LABVIEW. General operating procedures are outlined in Sect. 5

[en] In light of the recent TRIPLE results showing large parity-nonconserving (PNC) effects in epithermal neutron resonances in heavy nuclei, we have examined the possibility of studying parity violation via (p,α) resonance reactions in s-d shell nuclei, Such measurements could complement the neutron studies by providing the first determination of V_rms, (the rms PNC matrix element) in lighter nuclei. We have used experimental resonance parameters to estimate the magnitude of expected effects. We find that a segmented detector with large solid-angle could yield a sufficient count rate without significantly reducing the large angular effects which are often present. We shall also discuss the issue of data analysis; an analysis similar to that of the neutron work is appropriate, but some of the approximations used in the neutron analysis often are not suitable for proton resonances

[en] The effect of isospin symmetry breaking on level statistics has been examined with the nuclear shell model. The eigenvalues and electromagnetic transitions were calculated with the program OXBASH for the nuclide ²⁶Al for conserved isospin and for broken isospin. The long-range correlations of the eigenvalues, as measured by Δ₃, show good agreement between the experimental results and the calculations. However, there are discrepancies between data and calculations for the short-range correlations of the eigenvalues