Calvin Howell, PhD

Professor of Physics
Address: 221 Dfell
Durham, NC 27708
Phone: (919) 660-2632

Research Interests

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. 


Springer, Roxanne, et al. “International Workshop on Next Generation Gamma-Ray Source.” Journal of Physics G: Nuclear and Particle Physics, vol. 49, IOP Publishing, Dec. 2021.

Finch, S. W., et al. “Measurements of Short-Lived Isomers from Photofission as a Method of Active Interrogation for Special Nuclear Materials.” Physical Review Applied, vol. 15, no. 3, Mar. 2021. Scopus, doi:10.1103/PhysRevApplied.15.034037.

Aprahamian, A., et al. “ARUNA: Advancing Science, Educating Scientists, Delivering for Society.” Nuclear Physics News, vol. 31, no. 4, Jan. 2021, pp. 4–14. Scopus, doi:10.1080/10619127.2021.1988470.

Kading, E. E., et al. “Tests and calibrations of nuclear track detectors (CR39) for operation in high neutron flux.” Physical Review Research, vol. 2, no. 2, June 2020. Scopus, doi:10.1103/PhysRevResearch.2.023279.

Li, X., et al. “Compton scattering from $^{4}\mathrm{He}$ at the TUNL $\mathrm{HI}\ensuremath{\gamma}\mathrm{S}$ facility.” Prc, vol. 101, no. 3, American Physical Society, Mar. 2020, p. 034618. Manual, doi:10.1103/PhysRevC.101.034618.

Li, X., et al. “Compton scattering from 4He at the TUNL HIγS facility.” Prc, vol. 101, no. 3, American Physical Society, Mar. 2020, pp. 034618–034618. Manual, doi:10.1103/PhysRevC.101.034618.

Friesen, F. Q. L., and C. R. Howell. “A functional form for liquid scintillator pulse shapes.” Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 955, Mar. 2020. Scopus, doi:10.1016/j.nima.2019.163302.

Malone, R. C., et al. “Neutron-neutron quasifree scattering in neutron-deuteron breakup at 10 MeV.” Physical Review C, vol. 101, no. 3, Mar. 2020. Scopus, doi:10.1103/PhysRevC.101.034002.