Vacuum ultraviolet plasma arc radiation source for the 300-1000-a wavelength region.
A plasma arc radiation source is described which can produce continuum radiation in the 300-1000-A range from discharges in the gases He, Ne, Ar, Kr, Xe, H(2), and their mixtures. The radiation is emitted from a dc self-stabilized plasma arc column having a core temperature of about 18,000 K. The spectra of major interest are due to ion-electron recombination to the ground state of the neutral atom. These continua extend to wavelengths shorter than the first ionization threshold. For helium, the useful continuum extends from 504 A to approximately 350 A. The arc column is observed along its cylindrical axis of symmetry through a small opening in the anode. The radiation source was developed for use in the measurement of cross sections in the vacuum uv using continuously scanning photoelectric spectrometers. The application of the source to measurements in krypton near 500 A is described.
Levy
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Huffman
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