Experimental Detection of Transition Radiation

TLDR

All four present. Purpose+Mechanism combined in first line: The transition (Lilienfeld) radiation emitted by an electron incident on a metal is studied for W, Ta, Mo, Ti, Pt, Ag, Ni, Al, Cu, and Cs. That's the purpose and mechanism? Actually purpose: study of transition radiation.

Abstract

The transition (Lilienfeld) radiation emitted by an electron incident on a metal is studied for W, Ta, Mo, Ti, Pt, Ag, Ni, Al, Cu, and Cs. The radiation is found to be independent of the target temperature and gas pressure. The radiation is almost completely plane polarized, and forms a continuum. The radiation intensity is measured as functions of the target metal, emission angle, wavelength, electron energy, and current density. (T.F.H.)