Outer-shell photoionization of ions

Conference · Mon Aug 01 04:00:00 EDT 1994

OSTI ID:61762

Avdonina, N ^[1]

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1. Univ. of Pittsburgh, PA (United States)

It is well known that the photoionization cross section for a pure Coulombic potential decreases monotonically with photon energy. But for many-electron neutral atoms and ions, the photoionization cross sections display some non-monotonic features, such as Cooper minima, shape-resonances, and autoionizing resonances. It was found previously that increase of ionicity along an isoelectronic series results in the disappearance of low lying Cooper minima, which shift into the discrete spectrum. Shape-resonances also disappear because there is no potential barrier for the potentials of highly charged ions. So the photoionization cross sections calculated in one-particle approximation become monotonically decreasing functions of photon energy. The situation is different if one takes into account inter-shell correlations. The neat threshold behaviour of photoionization cross section of outer shell electrons is strongly affected by the great number of autoionizing resonances associated with the multielectron inner shells. Some of the resonances can occur near the outer shell photoionization threshold even for highly charged ions, and so can distort the otherwise monotonic behaviour of the photoionization cross sections.

• Research Organization: Argonne National Lab., IL (United States)
• OSTI ID: 61762
• Report Number(s): ANL/APS/TM--14; CONF-9404198--; ON: DE95006077; CNN: Grant PHY9005765
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ATOMS
HARTREE-FOCK METHOD
IONS
PHOTOIONIZATION
RANDOM PHASE APPROXIMATION