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Structure of 14C via Elastic and Inelastic Neutron Scattering from 13C: Measurement, R-matrix Analysis, and Shell Model Calculations

Resler, David Alan

Abstract Details

1987, Doctor of Philosophy (PhD), Ohio University, Physics and Astronomy (Arts and Sciences).
The specific purpose of this work is to provide a better understanding of the 14C level structure; the general purpose is to provide the details for using shell model calculations in R-matrix analyses. Using the TOF facilities of the Ohio University Accelerator Laboratory, the elastic and first 3 inelastic differential scattering cross sections for 13C+n were measured at 69 energies for 4.5 ≤ En ≤ 11 MeV. A multiple scattering code was developed which provided a simulation of the experimental scattering process allowing accurate corrections to the small inelastic data. The integrated 13C(n,α)10Be cross section is estimated. The sequential 2n-decay of 14C states populated by 13C+n was observed. A shell model code was developed. Normal and non-normal parity calculations were made for the lithium isotopes using a new two-body interaction. The results for 5Li predict the 2s1/2 and 1d5/2 single-particle states to be located below the 3/2+ (Ex = 16.66 MeV) state. Similar calculations were made for 13C,13N, and 14C. Results for 13C and 13N show for Ex < 10 MeV the Thomas-Ehrman shifts are related to the 2s1/2 single-particle energies. For 7Li and 14C, 2ℏω calculations were done. Shell model calculations generated the R-matrix parameters for the elastic and first 3 inelastic channels of 13C+n. After adjusting some energies, the predicted structure generally agrees with experiment for En < 4 MeV. Previous elastic 13C+n data were refit to replace Ro background terms by more realistic broad states and to get better agreement with model calculations. R-matrix fitting of the full data set produced new 14C level information. For En > 4 MeV (Ex > 12 MeV), 5 states are given defining Jπ assignments; 3, tentative assignments. The procedure for using shell model calculations in R-matrix analyses is given. New and more consistent 14C level information is obtained.
Raymond Lane (Advisor)
491 p.

Recommended Citations

Citations

  • Resler, D. A. (1987). Structure of 14C via Elastic and Inelastic Neutron Scattering from 13C: Measurement, R-matrix Analysis, and Shell Model Calculations [Doctoral dissertation, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1472558171

    APA Style (7th edition)

  • Resler, David. Structure of 14C via Elastic and Inelastic Neutron Scattering from 13C: Measurement, R-matrix Analysis, and Shell Model Calculations. 1987. Ohio University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1472558171.

    MLA Style (8th edition)

  • Resler, David. "Structure of 14C via Elastic and Inelastic Neutron Scattering from 13C: Measurement, R-matrix Analysis, and Shell Model Calculations." Doctoral dissertation, Ohio University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1472558171

    Chicago Manual of Style (17th edition)