HARPS... North HARPS-N PDR Harvard CfA, 06/ Thermal enclosure

3-level concept Spectrograph room: K Isolation Box: K Spectrograph: K 15°C 17°C T-sensor

Spectrograph room Model : YORK YEB 3S Serial Nr. : DN003

Room thermal control

Isolation Box

Temperature control ✓ Lakeshore 331S T-controller + diode sensors + heaters ✓ 60 mm polyurethane panels with 1 mm Al skin ✓ Floor isolated by 100-mm foam ‘carpet’ ✓ Thermal load on external room: about 10 W/K

Performances, but...

Lessons learned Concept works well and is simple Changing thermal load through feet produces gradient and seasonal effects ➡ Thermal isolation of feet ➡ Heater below feet, Tref = vacuum vessel e.g. using Lakeshore controller