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. “Toward a resolution of the neutron-neutron scattering-length issue.” Physics Letters, Section B: Nuclear, Elementary Particle and High Energy Physics, vol. 444, no. 3–4, Dec. 1998, pp. 252–59. Scopus, doi:10.1016/S0370-2693(98)01386-0. Full Text
Niculescu, I., et al. “Calibration of a Neutron Polarimeter to Measure the Electric Form Factor of the Neutron.” Ieee Transactions on Nuclear Science, vol. 45, no. 1, Dec. 1998, pp. 68–74. Scopus, doi:10.1109/23.659556. Full Text
Park, S. H., et al. “OK-4/Duke monochromatic γ-ray source: Performance and prediction.” Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 407, no. 1–3, Apr. 1998, pp. 224–28. Scopus, doi:10.1016/S0168-9002(97)01400-9. Full Text
Tornow, W., et al. “Scattering length measurements from radiative pion capture and neutron-deuteron breakup.” Nuclear Physics A, vol. 631, Mar. 1998, pp. 421–25. Scopus, doi:10.1016/s0375-9474(98)00040-2. Full Text
Howell, C. R., et al. “Implications of the space-star anomaly in nd breakup.” Nuclear Physics A, vol. 631, Mar. 1998, pp. 692–96. Scopus, doi:10.1016/s0375-9474(98)00093-1. Full Text
Tornow, W., et al. “Nuclear research at Duke .” Science, vol. 279, no. 5350, Jan. 1998, pp. 462–63.
Al-Ohali, M. A., et al. “Determination of the neutron detection efficiency of an NE213 scintillator for En = 2.5 to 16 MeV using the 2H(d, n)3He reaction.” Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 396, no. 3, Sept. 1997, pp. 388–93. Scopus, doi:10.1016/S0168-9002(97)00701-8. Full Text
Felsher, P. D., et al. “Analyzing power measurements for the [Formula Presented] breakup reaction at 12 MeV.” Physical Review C Nuclear Physics, vol. 56, no. 1, Jan. 1997, pp. 38–49. Scopus, doi:10.1103/PhysRevC.56.38. Full Text
Setze, H. R., et al. “Verification of the space-star anomaly in nd breakup.” Physics Letters, Section B: Nuclear, Elementary Particle and High Energy Physics, vol. 388, no. 2, Nov. 1996, pp. 229–34. Scopus, doi:10.1016/S0370-2693(96)01069-6. Full Text