CryoTiger

The FIES CryoTiger that cools the detector was not giving us the expected performance, the cold-head was only reaching -160C where we would expect closer to -200C. It was believed the problem was due to contamination in the system. The people at the Liverpool Telescope were consulted, since they have several CryoTiger systems and more experience in using them. They provide use with a manual and advice for cleaning the whole system, which we carried out. After filling with new gas we now achieving the expected -200C at the cold-head and a stable CCD temperature.