- Access by Xinjiang University
Properties of Excited States of . II. Gamma-Ray Angular Distributions and Correlations
Phys. Rev. 131, 787 – Published 15 July, 1963
DOI: https://doi.org/10.1103/PhysRev.131.787
Abstract
Angular distributions and triple correlations of gamma rays emitted from several resonances in the range keV in the reaction have been measured using thin, highly enriched targets. The decay schemes of these resonances and of intermediate levels excited in were presented in an earlier paper (I). The angular distributions and correlations lead to the resonance level assignments , , , , , , and where the proton resonance energies are in keV. The results indicate even parity for all of the resonances if it is assumed that all gamma-ray multipolarity mixings are of the form . The mixing ratios (all of the type ) are presented for most of the observed primary transitions and of several secondary transitions. The results of this study are consistent with the assignments , , , , , and made elsewhere for the 1.27-, 2.23-, 3.13-, 3.29-, 3.51-, and 4.19-MeV levels of . The 3.41-MeV level is identified as by means of angular-distribution and correlation measurements at the 1509-keV resonance. A assignment for the 3.41-MeV level casts doubt upon the existence of a weak transition, which has been reported by earlier workers and in I, from that level to the ½+ ground state. Results of several measurements designed to determine the origin of the weak gamma-ray peak of approximately 3.4 MeV in coincidence spectra at the 1509-keV resonance were inconclusive. Angular distributions at the 1204-keV resonance lead to the assignment of to the 4.26-MeV level. Limitations are placed on the possible assignments for the 4.43- and 5.01-MeV levels. Both members of the recently discovered doublet near keV are found to decay mainly to the ground state, and each have on the basis of angular distributions. The value of has been determined for each of the resonances. Results of this study are discussed in terms of recent collective model calculations for .
References (29)
- G. I. Harris and L. W. Seagondollar, Phys. Rev. 128, 338 (1962)
- E. E. Baart, L. L. Green, and J. C. Willmott, Proc. Phys. Soc. (London) 79, 237 (1962)
- L. L. Green, G. Kaye, and J. C. Willmott, Nucl. Phys. 25, 278 (1961)
- L. L. Green (private communication)
- V. K. Thankappan and S. P. Pandya, Nucl. Phys. 19, 303 (1960)
- G. I. Harris, Bull. Am. Phys. Soc. 7, 462 (1962)
- C. Broude, L. L. Green, and J. C. Willmott, Proc. Phys. Soc. (London) 72, 1097, (1958)
- P. M. Endt (private communication)
- F. W. Prosser, Jr., and H. D. Graber (private communication)
- M. E. Rose, Phys. Rev. 91, 610 (1953)
- A. L. Stanford, Jr., and W. K. Rivers, Jr., Rev. Sci. Instr. 30, 719 (1959)
- R. E. Smith, thesis, Air Force Institute of Technology, Air University, Wright-Patterson Air Force Base, Ohio, 1961 (unpublished)
- P. B. Parks, H. W. Newson, and R. M. Williamson, Rev. Sci. Instr. 29, 834 (1958)
- A. J. Ferguson and A. R. Rutledge, "Coefficients for Triple Angular Correlation Analysis in Nuclear Bombardment Experiments" Atomic Energy of Canada, Ltd., CRP-615, AECL-420, 1957 (unpublished)
- F. W. Prosser, Jr., R. W. Krone, and J. J. Singh, Phys. Rev. 129, 1716 (1963) M. E. Rose, Oak Ridge National Laboratory Report ORNL-2516, 1958 (unpublished)
- W. T. Sharp, J. M. Kennedy, B. J. Sears, and M. G. Hoyle, "Tables of Coefficients for Angular Distribution Analysis," Atomic Energy of Canada, Ltd., CRT-556, AECL-97, 1957 (unpublished)
- [7]
- H. E. Gove, in Nuclear Reactions, edited by P. M. Endt and M. Demeur, (North-Holland Publishing Company, Amsterdam (1959) pp. 310, 311 [14] [H. E. Gove (private communication)]
- A. E. Ligherland, E. B. Paul, G. A. Bartholomew, and H. E. Gove, Can. J. Phys. 37, 53 (1959)
- G. J. McCallum, Phys. Rev. 123, 568 (1961)
- [G. I. Harris and L. W. Seagondollar, Bull. Am. Phys. Soc. 7, 301 (1962)]
- P. B. Smith and P. M. Endt, Phys. Rev. 110, 1442 (1958)
Omitted endnote
- L. Simons, Nucl. Phys. 10, 215 (1959)
- G. I. Harris (to be published)
- V. K. Thankappan, Phys. Letters 2, 122 (1962)
- P. M. Endt and C. H. Paris, Phys. Rev. 106, 764 (1957)
- P. M. Endt and C. Van der Leun, Nucl. Phys. 34, 1 (1962)
Omitted endnote