HARPS ... North

HARPS-N PDR Harvard CfA, 06/07-12-2007

Thermal enclosure

3-level concept

Spectrograph room: +- 0.2 K

Isolation Box: +- 0.01 K

Spectrograph: +- 0.001 K

15°C

17°C

T-sensor

Spectrograph room

Model : YORK YEB 3S

Serial Nr. : 135.157.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