Inner-shell Photoionization at Relativistic Energies
Abstract
At relativistic energies the cross section for the photo effect drops off as does the cross section for liberating any bound electron through Compton scattering. However, when the photon energy exceeds twice the rest mass of the electron, ionization may proceed via electron-positron pair creation. The cross section for this channel saturates at several times the threshold energy, and hence the most probable way of photoionizing an atom at high energy is to make the vacuum spark. We present estimates for the cross section for this "vacuum assisted photoionization" which proceeds either via direct pair creation on the bound electron or via pair creation on the atomic nucleus binding the inner-shell electron followed by an electron-electron or positron-electron encounter.
- Publication:
-
APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 1998
- Bibcode:
- 1998APS..DMP..E605I