Measuring Temperature Use IR camera –Note measurements in vacuo through window introduce an offset (!) –Extra thermal sensors for recalibration –Linearity Is it maintained? Seems to be to about 1C over range –20 to +20.
Improvements Holes in kapton –a la ATLAS Non uniform thickness –Frame engineered in CF can reduce operating temperature by several degrees –Minimize(reduces) the amount of material
Mechanical Hybrid 2 nd prototype CF manufactured –Photo available if necessary –Bows <50 microns across 10cm –Precision slots manufactured in CF using spark erosion But slow and expensive 3 rd CF prototype –Reduce the bow < 25 microns –Insert the TPG Aliminium Nitride Substrates exist (correct size and thickness). –Laser cutting –Bonding to TPG
Adjustments- Translations X –6 microns/5 degrees Y –7 microns/5 degrees Z –2 microns/5 degrees (*)
Rotations Slew –0.88 degree for full scale(see Y drive) Roll –0.25 degree for 360 degree adjustments(8 microns drive/5 degree adjustments) Pitch –0.26 degree for 540 degrees adjustment(10 microns approx in y/5 degree)
Thermal Measurements Preliminary look at the alignment mechanism –Increase temperature of base by +10 degrees relative to platform –X,Z movement small but large pitch O(100)micron
Conclusions Thermal module –Real prototype being built –All components –Calibration model consistent with measurement Mechanical Alignement –2 nd prototype mechanism behaves much as expected –Need to understand problem thermal movement Module modifications –Cabling (cf. N.A. Smith next week!)