A gas flow proportional counter for the Mössbauer study of surfaces between 100 K and 400 K

A gas flow proportional counter has been constructed for operation between 100K and 400K without the need for an evacuated cryostat. The detector is temperature controlled and may be used for detecting conversion electrons or X-rays. Six different gases, pure He, He/1%CH₄, He/5%CH₄, He/10%CH₄, He/5%Co, and Ar/5%CH₄ have been investigated in order to obtain maximum efficiency and reliability of operation. At room temperature and above, all gases are suitable. At low temperatures, He/5%Co is the most suitable for electron detection, For X-ray detection, Ar/5%CH₄ is suitable over the entire temperature range.