The Pressure Modulators, Closed Cycle Coolers And Detector Cooling System In ISAMS

Earlier pressure modulator designs have been developed to produce a new mechanism having opposed and balanced pistons. The mechanism operates as a coupled resonant system, with new control electronics providing better amplitude and frequency stability. Careful choice of materials used in construction of the modulators, together with the use of a silicalite molecular sieve, is expected to lead to improved stored gas stability. Stirling cycle coolers developed for ISAMS are to be installed as servo controlled balanced pairs, the effectiveness of this compensating technique has been demonstrated during testing. Connection of the coolers to the widely spaced detectors is effected by a co-axial thermal connection system. Detector mounts which minimise heat leaks whilst providing mechanical rigidity and adjustment of the optics within them have been designed employing tubular metal legs in a stool arrangement.