ELECTRON-GUN AND COLLECTOR FOR THE FERMILAB HIGH-ENERGY ELECTRON COOLING

In this paper, we discuss results of 25-50 kV electron gun and collect or bench tests performed as part of the R&D program to develop MeV-ran ge electron cooling at Fermilab. We found that by controlling the cath ode emitting area using a negatively biased electrode one can form an electron beam with an extremely small halo. We also present results of the tests for the electron collector with a transverse magnetic field . One can show that for this type of collector the flux of secondary e lectrons is about 100 times smaller than the flux in a traditional axi ally symmetric scheme with a potential barrier. (C) 1998 Elsevier Scie nce B.V. All rights reserved.