Airborne Particle Counter

Airborne Particle Counter

The small fibre (1.6 arcsec diameter) module was successfully commissioned on July 2001. The Small Fibre module contain 150 fibres with 1.6 arcsec diameter (90 micron), which run without connectors from AF2 to WYFFOS. The fibres are high-content OH fused silica made by Polymicro. Compared to the Large Fibre module, small fibres have the following main two advantages: 1) no light loss is due to fibre connectors, providing a more homogeneous distribution of fibre relative throughput; 2) the sky/background contribution in observations with the small fibres is 0.35 times smaller than with the large fibres. This means that, with the small fibres, the noise level in sky-limited observations is down by a factor of 0.6.

Instrument type