Photoionization dynamics of Na 3s in the Cooper minimum region

The photoionization cross section of 3s orbital of sodium atom has a Cooper minimum (CM) near its threshold region [1]. It is known that photoionization parameters are very sensitive to the presence of CM [2, 3]. Also, in the region of CM, the effects of quadrupole transitions are important while determining the angular distribution parameters. Here we report the effect of quadrupole transition near the 3s dipole CM [4,5] on the angular distributions of Na 3s which is an open shell system. We also include the study of spin polarisation of photoelectrons in this region [6]. The required transition amplitudes for these calculations are obtained from RATIP [7]. The wavefunctions of the initial and ionised state of the system are obtained from GRASP [8]. [1] J. W. Cooper, Phys. Rev. 128, 681 (1962); [2] S. T. Manson and A. F. Starace, Rev. Mod. Phys., 54, 389 (1982); [3] M. S. Wang, et.al, Phys. Rev. A 25, 857 (1982); [4] W. R. Johnson and C. D. Lin. Phys. Rev. A 20, 964 (1979); [5] W. R. Johnson, et.al, Phys. Rev. A 59, 3609 (1999); [6] K.-N. Huang, Phys. Rev. A 22, 223 (1980); [7] S. Fritzsche, Comp. Phys. Comm. 183, 525 (2012); [8] F.A. Parpia, C. Froese Fischer, I P. Grant, Comp. Phys. Comm. 94, 249 (1996),