Density effect in relativistic K-shell ionization

Research paper by D. W. Spooner, W. E. Meyerhof, J. J. Kuffner, E. C. Montenegro, K. Ishii, S. E. Kuhn, D. M. Kawall, D. G. Jensen, Z. E. Meziani

Indexed on: 01 Dec '94Published on: 01 Dec '94Published in: Zeitschrift für Physik D Atoms, Molecules and Clusters


Using a grazing emission method, we have made measurements of 22.6-GeV electron impact ionization cross sections at the front and back faces of ∼ 70-µm thick Al and Cu foils. These give, respectively, the cross sections without and with a density effect predicted by Fermi. For Cu, the back cross section ratio at 22.6 and 5.1 GeV (previously measured) is 1.00±0.04, confirming the predicted energy independence of this cross section. The absolute cross sections agree overall with theoretical calculations.