Measurement of the velocity of low-temperature plasma jets

Design data are given for an experimental apparatus to record brightness inhomogeneities in a plasma jet over a narrow spectral region at two cross sections separated along the length of the jet. The isolation of a narrow segment from the jet radiation spectrum increases the depth of brightness fluctuations, and the use of a photomultiplier increases the sensitivity of the apparatus so that a weakly glowing jet can be investigated. A process is recorded by high-speed filming of the screen of an electron oscilloscope.