Design and Construction of a Vacuum-Grating Spectrograph for the Infrared

The Problem: At the time the work was begun, it was proposed that the system be designed to be as automatic as possible without restricting the versatility and resolving power of the instruments. The plan was to construct parts for both single and double pass instruments in so far as the parts were alike, and then to complete the single pass instrument and determine its characteristics before completing the double pass unit.

With the gratings now available the theoretical resolution limit of the single pass instrument should range from 0.075 cm^-1 to 0.030 cm^-1 depending on the angle at which the grating is used. The gratings, however, are not perfect and will probably produce only 80 per cent of their theoretical resolving power. Thus it was expected that the single pass instrument would have a resolution limit of 0.095 to 0.037 cm^-1.

It was the aim of this work to carry out the above program, completing only the single pass instrument, with the hope of attaining the resolution limit stated above.