People » Hari Saha


Dr. Saha received his PhD in Physics from Calcutta University in 1978. He joined , Max-Planck-Institute for Physics and Astrophysics, Munich, Germany as a Max-Planck Post-doctoral fellow 1979-1981. He was a Research Specialist in University of Minnesota, Minneapolis for one year (1981-1982), and a Research Associate in Vanderbilt University, Nashville, 1982-1985. He worked as a Research Scientist for three years in Supercomputer Computations Research Institute, Florida State
University, Tallahassee before joining UCF in 1987 where he is a full Professor.

My research is directed towards understanding the fundamental details of the structure and dynamics of electrons within the atoms and molecules through theoretical analysis of the interaction of photons, electrons and positrons with individual atoms and molecules in the gas phase. Over the past twenty years some of the most productive activities in atomic physics research have been in the area of photoionization and collision processes which sample the dynamics associated with continuum wave functions (unbound states) of electrons. Experimental results have stimulated development of a number of new calculational techniques for describing these systems, with a particular view toward accounting for the electron correlation and core polarization associated with the motion of an electron in the field of other electrons. To date, none of these new methods have allowed for exploitation of the most accurate technique of description of bound state systems, the Multiconfiguration Hartree-Fock (MCHF) scheme, beyond its use as a starting point for “closed” portions of the wave function. As the MCHF technique incorporates electron configuration interaction in a way superior to other techniques, the extension of this scheme to include continuum wave functions is a problem of cardinal importance in atomic theory. The primary aim of my research is devoted to just this activity.

1. Proton-hydrogen collisions by the Faddeev approach

Haripada Saha, J. Chowdhuri and N.C. Sil,  Phys  Rev  A14 (1976) 2372-2378

 

2. Asymptotic cross section for the excitation of atomic hydrogen by proton and alpha particle impact

H.P. Saha and B.C. Saha,  Physics Letters, 69A (1978) 180-184

 

3. Evaluation of exchange matrix elements with momentum transfer for ion-atom collisions

H.P. Saha and N.C. Sil,  J. Phys. B12 (1979) 585-594

4. Rearrangement collisions in highly excited states of atomic hydrogen

– N.C. Sil, B.C. Saha, H.P. Saha and P. Mandal, Phys. Rev.  A19 (1979) 655-674

 

5. Electron-impact excitation of atomic hydrogen into highly excited states

– B.C. Saha, H.P. Saha and N.C. Sil,  J. Phys. Soc. Japan 47 (1979) 1634-1642

6. Electron capture in 3s level by proton and alpha-particle from atomic hydrogen

H.P. Saha, N. Maiti and N.C. Sil, J. Phys B13 (1980) 327-342

7. Asymptotic behavior of cross sections for the electron impact excitation of  hydrogen atom into highly excited states

– B.C. Saha, H.P. Saha and N.C. Sil,  Ind. J. Phys.  55B (1981) 16-29

 

8. Electron impact excitation of Si X

H.P. Saha and E. Trefftz , J. Phys. B15 (1982) 1089-1104

 

9. Electron Collisional excitation of S XII

H.P. Saha and E. Trefftz,  Zeitscrift fur Naturforsch 37a (1982) 744-751

 

10. Coronal line intensities for ions with Fine structured ground states: Si X

H.P. Saha and E. Trefftz, Astron. and Astrophys. 116 (1982) 224-231

11. A theory of Laser induced Chemiionization  I. Quantal formulation

H.P. Saha, John S. Dahler and S.E. Nelson, Phys. Rev. A28 (1983) 1487-1502

 

12. Calculations of coronal line intensities for Boron-like ions

H.P. Saha and E. Trefftz, Solar Phys.  87 (1983) 233-242

13. A theory of Laser induced Chemiionization   II. A semiclassical limit

H.P. Saha and John S. Dahler,  Phys. Rev. A82 (1983) 2859-2867

14. Excitation of C II lines by Photoionization of neutral Carbon

– H. Hofmann, H.P. Saha and E. Trefftz, Astron. and Astrophys. 126 (1983) 415-426

15. Multiconfiguration Hartree-Fock results with Breit-Pauli corrections for  forbidden transitions in the 2p4

configuration

– C. Froese Fischer and H.P. Saha,  Phys. Rev. A28 (1983) 3169-3178

16. MCHF + BP results for electric dipole transitions in the Oxygen sequence

– C. Froese Fischer and H.P. Saha, J. Phys. B17 (1983) 943-952

 

17. A theory of laser induced excitation transfer and atomic association

H.P. Saha, John S. Dahler and Dumont M. Jones, Phys. Rev.  A30 (1984) 1345-1352

18. A theory of excitation transfer between Rydberg atoms

H.P. Saha and T.F. George, Mol. Phys.  55 (1985) 173-186

 

19. Recent advances in the theory of Chemiionization

H.P. Saha, Kai-shue-Lam and Thomas F. George,  ‘ Gas-Phase Chemiluminiscence and Chemiionization’,

edited by A. Fontijn (North-Holland, Amsterdam ) 1985

20. Multiconfiguration Hartree-Fock results with Breit-Pauli corrections for  transitions in the 2p2 configuration

– C. Froese Fischer and H.P. Saha,  Physica  Scripta  32 (1985) 181-194

21. An extension of the multiconfiguration Hartree-Fock program for continuum functions

– C. Froese Fischer and H. P. Saha,  Technical Report, 1983, DOE-ER-1061811, Vanderbilt University,

Nashville, Tennessee 37235

 

22. MCHF calculation of the Oscillator strength for the 2s2p 1Po –> 2p2, 2snd 1D  (n=3-6) transitions in Beryllium

H.P. Saha and C. Froese Fischer,  Phys. Rev.  A35 (1987) 5240-5243

 

23. Photoionization of Magnesium

– C. Froese Fischer and H. P. Saha, Can. J. Phys.  65 (1987) 772-776

 

24. Multiconfiguration Hartree-Fock calculation of the photoionization of the excited Na 4d state

H.P. Saha, M.S. Pindzola and R.N. Compton,  Phys. Rev. A38 (1988) 128-134

 

25. Numerical multiconfigurational Hartree-Fock studies of Atomic photoionization cross sections: Dynamical

Core-Polarization effects in Atomic Sodium

H.P. Saha, C. F. Fischer and P.W. Langhoff ,  Phys. Rev. A38 (1988) 1279-1285

26. Multiconfiguration Hartree-Fock calculation for the Bound-Free Photodetachment  Cross section of H-

H.P. Saha,  Phys. Rev. A38 (1988) 4546-4551

27. Numerical multiconfiguration self-consistent field studies of Atomic photoionization  Cross section:

Dynamical core polarization effects in Atomic Potassium

H.P. Saha,  Phys. Rev. A39 (1989) 628-633

28. Threshold behavior of the M-shell photoionization of Argon

H.P. Saha,  Phys. Rev. A 39 (1989) 2456-2460

29. Low energy elastic scattering of electrons from neon atoms

H.P. Saha,  Phys. Rev. A 39 (1989) 5048-5061

30. Accurate ab-initio calculation on low-energy elastic scattering of electrons from helium

H.P. Saha,  Phys. Rev. A 40 (1989) 2976-2990

 

31. K-shell photoionization of Beryllium

H.P. Saha  and  C. D. Caldwell, Phys. Rev. A 40 (1989) 7020-7025

 

32. Multiconfiguration Hartree-Fock calculation of the photoionization cross section  of the  Cs 7d excited state

H.P. Saha,  Phys. Rev. A 41 (1990) 174-180

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