518 Allen Hall

### Research

Interactions of electrons and photons in the field of an atom, atomic photoelectric effect, direct radiative recombination, bremsstrahlung, pair production, Rayleigh and Compton scattering, anomalous dispersion, analytic description of interior atomic radiation processes, atomic processes in high temperature and/or high density plasmas (astrophysics and fusion), transition in atomic processes from classical to quantum behavior, polarization correlations.

### Selected Publications

- "Sum rules for the polarization correlations in photoionization and bremssstrahlung," R. H. Pratt, R. A. Miller, and A. Surzhykov, Phys. Rev. A 93, 053421 (2016).
- "Photon absorption and photon scattering - What we don't know and why it matters," R. H. Pratt, Rad. Phys. Chem 95, 4-13 (2014).
- "Two-photon decay of inner-shell vacancies in heavy atoms," A. Surzhykov, R. H. Pratt, and S. Fritzsche, Phys. Rev A 88, 042512 (2013).
- "Cooper minima: A window on nondipole photoionization at low energy," G. B. Pradhan, J. Jose, P. C. Deshmukh, L. A. LaJohn, R. H. Pratt, and S. T. Manson, J. Phys. B 44, 21002 (2011).
- "Compton scattering from positronium and validity of impulse approximation," Z. Kalliman, K. Pisk, and R. H. Pratt, Phys. Rev. A 83, 053405 (2011).
- "Quadrupole matrix element zeros and their effects on photoelectron angular distributions," L. A. LaJohn, S. T. Manson, and R. H. Pratt, NIM A 619, 7-9 (2010).
- "K-shell scattering at high photon energies," V. Florescu and R. H. Pratt, Phys. Rev. A 80,033421 (2009).
- "Partial cancelations of correlations in nonrelativistic high energy asymptotics of photoeffect," E. G. Drukarev and R. H. Pratt, Phys. Rev. A 80, 013406 (2009).