Comparison of Direct Electron and Photon Activation Measurements
                             with FLUKA Predictions

                               George Kharashvili
                                 Jefferson Lab

Abstract:
Direct electron and photon activation are closely related processes.
Electronuclear interaction cross-sections are typically orders of magnitude
lower than those of photonuclear interactions. However, direct electron
activation is of significant importance in thin targets, where electron beam
exits the target without fully developing electromagnetic shower. Such cases are
of interest for both personnel and equipment protection purposes at Jefferson
Lab. In order to evaluate the relative importance of the direct electron
activation to the activation by an electromagnetic shower, two stacks of Al, Pb,
Nb, Cu, and stainless steel foils (0.01 x 0.1 mm) were placed in 2.25 and
3.35-GeV electron beams. The two stacks were separated by 1.25-cm thick tungsten
block. Gamma spectroscopy analysis of each foil was then performed using high
purity germanium detectors. Comparison of the measured activities to the FLUKA
predictions is presented.