A Microwave-Powered Hydrogen Lamp for Vacuum Ultraviolet Photochemical Research

Abstract

An intense hydrogen light source for use in photochemistry is described, which yields intensities of up to 10¹⁶ quanta/sec in the 1100–1850 Å spectral region. Intensity measurements were made employing the photochemical formation of ozone in a flow of oxygen and the photoelectric volume effect in a nickel cathode. The intensity distribution was obtained mainly from spectrometric work. Typical observed intensities were 3 × 10¹⁵ quanta/sec in the 1400–1650 Å region and 3 × 10¹⁵ quanta/sec for Lyman-alpha at 1216 Å. Under the influence of the discharge the transmittance of LiF windows gradually decreases; however, the percentage decrease is a well-reproducible function of time.