FIES building

The outside of the building and the surrounding area were painted white. It was found that there was a strong gradient in the temperature in the front room, being highest close to the door to the FIES room. This was thought to be due to the CryoTiger which is close to the door, and the CryoTiger was moved across from the outside entrance door. Also, the cooling water which is used to regulate the temperature in the front room is set higher in the summer to avoid problems with the telescope tracking, which limits the cooling capacity and might indirectly affect the temperature in the FIES room. This should be improved with the changes to the cooling system (see above).

It was also decided to increase the nominal temperature at which the FIES room is kept by one degree. For this, two temperature loops will have to be adjusted and tweaked, but due to schedule constraints this was not done in time for summer 2013. If the cooling water problem can be solved, possibly there is no need for this rise of the nominal temperature of the FIES room and spectrograph.

A long standing issue has been that if the FIES dewar needs to be pumped, a lot of heat is generated in the room itself, affecting the temperature stability. To allow pumping the FIES dewar without heating the FIES room a system was designed where the dewar (through an extended tube) is connected to a pump in the front room. For this a hole from the front room to the FIES room was made. As the wall is made of armed-concrete a company had to be contracted with a proper drilling machine.

Thomas Augusteijn 2013-12-02