A compact vacuum UV excilamp on argon dimers

Abstract

The energy and spectral characteristics of the argon dimer emission with the maximum at a wave-length of ∼126 nm under excitation by a pulse-periodic discharge in a gas flow with pressures higher than the atmospheric pressure are studied. A compact excilamp has been designed for obtaining radiation in the vacuum ultraviolet spectrum region. The minimal argon flow velocities are determined, at which cooling is effected by convective gas ejection from the discharge region. This allows one to form a diffusion discharge with a stable radiation power density. It is shown that, when the flow velocity is 0.5 m³/h, the radiation power density of an Ar₂* molecule is >100 μW/cm² behind a LiF window with ∼10% transmission at a wavelength of 126 nm. It is shown that the use of a windowless design and an increase in the gas flow velocity allows an increase in the radiation power density up to 10 mW/cm².