Astrospectrometer having a Fabry-Perot multiplex

An Astrospectrometer, having a Fabry-Perot multiplex, is described. The spectrometer, mounted in the fixed focus system of the LAT telescope, has a 1:30 relative aperture, an operating spectral interval of 3600-6000 A, and a spectrometry resolution limit of 0.01 A. The dimensions of the multiplex spectrometer are smaller by a factor of two than those of a spectrometer having one etalon. The internal scheme of hybridizing the multiplex with a monochrometer results in a minimum number of optical elements, a high precision in the finishing of the operating surfaces of the multiplex plates, and a high stabilization accuracy; these advantages give a spectrometer transmission of 40 percent. The high-precision adjustment and stabilization of the gaps between the etalon plates make it possible to change the multiplex resolution without breaking the seal of the instrument, and to switch to different spectral ranges. In a spectrometer having the multiplex and multichannel receivers, a 150 A spectral interval is covered by scanning with a 0.01 A resolution in 30 channels, compared to a 12 A interval for spectrometers with only one etalon. The multiplex spectrometer can operate with a conventional single-channel receiver as well; the energy advantage is about seven times greater than for the operation of a spectrometer with one etalon, due to the large diaphragm.