A double-pass Sisam spectrometer of high resolution and sensitivity, previously described, has been modified for single-pass operation. For discrete line emission sources, this modification provides a gain of a factor of 6 in sensitivity at the expense of a loss of a factor of 2 in resolution in the near infra red region. As is demonstrated, the modified instrument is particularly suitable for the study of weak spectral sources. A coherent modulation system has also been incorporated which eliminates the periodic variations in signal strength arising from the non-coherent modulation technique previously employed.
|Journal||Royal Society of London. Proceedings A. Mathematical, Physical and Engineering Sciences|
|Publication status||Published - 25 Mar 1977|