Wide Band, Wide Temperature Operating Range Acousto-optical Spectrometer (A.O.S) For The Balloon Borne Pronaos Submillimetre Heterodyne Experiment.

In order to fulfill the scientific objectives of the Pronaos balloon borne SubMill imetre heterodyne experiment, we developed a wide band A.O.S. (bandwidth > 700 MHz) having very good stability over a large operating temperature range (loo to 40"). The optimization of the frequency resolution of the spectrometer (B*T > 1000) was obtained in designing and building, in collaboration with Thomson-Sin tra, a new kind of Bragg cell in L i m o 3 (Y+123" orientation) centered at 2 GHz. We described the new solutions that we have implemented for minimizing the size, weight and power of the device and for improving its reliability. All these improvements lead to a very simple and reliable device as well adapted for space experiments as for low cost, ground based applications.