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.
Floyd, Carey E., et al. “Neutron-stimulated emission computed tomography of a multi-element phantom.” Phys Med Biol, vol. 53, no. 9, May 2008, pp. 2313–26. Pubmed, doi:10.1088/0031-9155/53/9/008. Full Text
Braun, R. T., et al. “Neutron-proton analyzing power at 12 MeV and inconsistencies in parametrizations of nucleon-nucleon data.” Physics Letters, Section B: Nuclear, Elementary Particle and High Energy Physics, vol. 660, no. 3, Feb. 2008, pp. 161–66. Scopus, doi:10.1016/j.physletb.2007.12.039. Full Text
Kapadia, A. J., et al. “Neutron stimulated emission computed tomography for diagnosis of breast cancer.” Ieee Transactions on Nuclear Science, vol. 55, no. 1, Jan. 2008, pp. 501–09. Scopus, doi:10.1109/TNS.2007.909847. Full Text
Howell, C. R. “Extracting the neutron-neutron scattering length from neutron-deuteron breakup.” Chiral Dynamics 2006 Proceedings of the 5th International Workshop on Chiral Dynamics, Theory and Experiment, Cd 2006, Dec. 2007, pp. 344–45.
Mikhailov, S. F., et al. “Commissioning of the booster injector synchrotron for the HIGS facility at Duke University.” Proceedings of the Ieee Particle Accelerator Conference, Dec. 2007, pp. 1209–11. Scopus, doi:10.1109/PAC.2007.4441032. Full Text
Sharma, A. C., et al. “Elemental spectrum of a mouse obtained via neutron stimulation.” Progress in Biomedical Optics and Imaging Proceedings of Spie, vol. 6510, no. PART 1, Oct. 2007. Scopus, doi:10.1117/12.713731. Full Text
Olcott, Peter D., et al. “Performance Characterization of a Miniature, High Sensitivity Gamma Ray Camera.” Ieee Transactions on Nuclear Science, vol. 54, no. 5, Institute of Electrical and Electronics Engineers (IEEE), Oct. 2007, pp. 1492–97. Crossref, doi:10.1109/tns.2007.902367. Full Text
Sharma, A. C., et al. “Design and development of a high-energy gamma camera for use with NSECT imaging: Feasibility for breast imaging.” Ieee Transactions on Nuclear Science, vol. 54, no. 5, Oct. 2007, pp. 1498–505. Scopus, doi:10.1109/TNS.2007.906058. Full Text
Hutcheson, A., et al. “Pulsed and monoenergetic beams for neutron cross-section measurements using activation and scattering techniques at Triangle Universities Nuclear Laboratory.” Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions With Materials and Atoms, vol. 261, no. 1-2 SPEC. ISS., Aug. 2007, pp. 369–72. Scopus, doi:10.1016/j.nimb.2007.04.097. Full Text
Muzichka, A. Y., et al. “Background determination for the neutron-neutron scattering experiment at the reactor YAGUAR.” Nuclear Physics A, vol. 789, no. 1–4, June 2007, pp. 30–45. Scopus, doi:10.1016/j.nuclphysa.2007.03.163. Full Text