Calvin R. Howell
Professor of Physics
Professor Howell’s research is in the area of experimental nuclear physics with emphasis on the quantum chromodynamics (QCD) description of low-energy nuclear phenomena, including structure properties of nucleons and nuclei and reaction dynamics in few-nucleon systems. The macroscopic properties of nucleon structure and the residual strong nuclear force between neutrons and protons in nuclei emerge from QCD at distances where the color interactions between quarks and gluons are strong. However, the details of the mechanisms that generate the strong nuclear force are not well understood. Effective field theories (EFT) and Lattice QCD calculations provide theoretical frames that connect low-energy nuclear phenomena to QCD. Professor Howell and collaborators are conducting experiments on few-nucleon systems that test predictions of ab-initio theory calculations for the purpose of providing insight about the QCD descriptions of low-energy nucleon interactions and structure. His current projects include measurements of the electromagnetic and spin-dependent structure properties of nucleons via Compton scattering on the proton and few-nucleon systems and studies of two- and three-nucleon interactions using few-nucleon reactions induced by photons and neutrons. In the coming years, a focus will be on investigating the neutron-neutron interaction in reactions and inside nuclei. In addition, his work includes applications of nuclear physics to national nuclear security, medical isotope production, and plant biology. Most of his research is carried out at the High Intensity Gamma-ray Source and the tandem laboratory at TUNL.
Howell, C. R., et al. “Scattering of polarized and unpolarized nucleons from 28Si.” Physical Review. C, Nuclear Physics, vol. 38, no. 4, Oct. 1988, pp. 1552–70. Epmc, doi:10.1103/physrevc.38.1552. Full Text
Tornow, W., et al. “Low-energy neutron-proton analyzing power and the new Bonn potential and Paris potential predictions.” Physical Review. C, Nuclear Physics, vol. 37, no. 6, June 1988, pp. 2326–31. Epmc, doi:10.1103/physrevc.37.2326. Full Text
Tornow, W., et al. “Search for a purported resonance in 13C at 20 MeV via analyzing power measurements of 12C(n,n).” Physical Review. C, Nuclear Physics, vol. 35, no. 4, Apr. 1987, pp. 1578–80. Epmc, doi:10.1103/physrevc.35.1578. Full Text
Howell, C. R., et al. “Comparisons of vector analyzing-power data and calculations for neutron-deuteron elastic scattering from 10 to 14 MeV.” Few Body Systems, vol. 2, no. 1, Mar. 1987, pp. 19–32. Scopus, doi:10.1007/BF01078989. Full Text
Honoré, G. M., et al. “Differential cross sections and analyzing powers for neutron elastic scattering from 89Y between 8 and 17 MeV.” Physical Review. C, Nuclear Physics, vol. 34, no. 3, Sept. 1986, pp. 825–34. Epmc, doi:10.1103/physrevc.34.825. Full Text
Honoré, G. M., et al. “Coupled-channel analysis of nucleon scattering from sup40Ca up to 80 MeV.” Physical Review. C, Nuclear Physics, vol. 33, no. 4, Apr. 1986, pp. 1129–40. Epmc, doi:10.1103/physrevc.33.1129. Full Text
Guss, P. P., et al. “Cross sections and analyzing powers for fast-neutron scattering to the ground and first excited states of 58Ni and 60Ni.” Nuclear Physics, Section A, vol. 438, no. 1, May 1985, pp. 187–211. Scopus, doi:10.1016/0375-9474(85)90124-1. Full Text
DELAROCHE, J. P., et al. “ENERGY-DEPENDENCE OF THE LOCAL OPTICAL-POTENTIAL FOR NEUTRON-NUCLEUS SCATTERING.” Aip Conference Proceedings, no. 124, AMER INST PHYSICS, Jan. 1985, pp. 310–11.
HOWELL, C. R. “SCATTERING OF POLARIZED AND UNPOLARIZED NEUTRONS FROM SI-28 AND S-32.” Aip Conference Proceedings, no. 124, AMER INST PHYSICS, Jan. 1985, pp. 72–89.
Howell, C. R. “Simultaneous measurements of analyzing powers and differential cross sections for N+28Si.” Ieee Transactions on Nuclear Science, vol. 30, no. 2, Jan. 1983, pp. 1132–35. Scopus, doi:10.1109/TNS.1983.4332471. Full Text