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.
Tonchev, A. P., et al. “Measurement of the Am241(γ,n)Am240 reaction in the giant dipole resonance region.” Physical Review C Nuclear Physics, vol. 82, no. 5, Nov. 2010. Scopus, doi:10.1103/PhysRevC.82.054620. Full Text
Brady, Samuel L., et al. “A feasibility study using radiochromic films for fast neutron 2D passive dosimetry.” Phys Med Biol, vol. 55, no. 17, Sept. 2010, pp. 4977–92. Pubmed, doi:10.1088/0031-9155/55/17/007. Full Text
Zhou, Z., et al. “Differential cross section for neutron scattering from Bi209 at 37 MeV and the weak particle-core coupling.” Physical Review C Nuclear Physics, vol. 82, no. 2, Aug. 2010. Scopus, doi:10.1103/PhysRevC.82.024601. Full Text Open Access Copy
Weisel, G. J., et al. “Neutron-deuteron analyzing power data at 19.0 MeV.” Physical Review C Nuclear Physics, vol. 81, no. 2, Feb. 2010. Scopus, doi:10.1103/PhysRevC.81.024003. Full Text Open Access Copy
Weisel, G. J., et al. “Neutron-deuteron analyzing power at 19.0 MeV.” Phys. Rev., vol. C 81, 2010.
Bowman, C. D., et al. “Basis for green energy multiplier*alternative nuclear technology (GEM*ART).” Transactions of the American Nuclear Society, vol. 100, Dec. 2009, pp. 578–79.
Weisenberger, A. G., et al. “Positron emission tomography detector development for plant biology.” Ieee Nuclear Science Symposium Conference Record, Dec. 2009, pp. 2323–28. Scopus, doi:10.1109/NSSMIC.2009.5402259. Full Text
Hutcheson, A., et al. “Cross sections for U238(n,n'γ) and U238(n,2nγ) reactions at incident neutron energies between 5 and 14 MeV.” Physical Review C Nuclear Physics, vol. 80, no. 1, Aug. 2009. Scopus, doi:10.1103/PhysRevC.80.014603. Full Text
Furman, W. I., et al. “Current status of the experiment on direct measurement of neutron-neutron scattering length at the reactor yaguar.” Aip Conference Proceedings, vol. 1109, May 2009, pp. 53–58. Scopus, doi:10.1063/1.3122261. Full Text