110 likes | 234 Views
Test on mirror support prototypes. M. Lenti. News from MARCON. Shipping at CERN of all the mirrors : end of 2010 – beginning of 2011 4 dummy segments ordered to be shaped and drilled as the mirrors ( without any optical threatment ) for our testing. Encoders.
E N D
Test on mirrorsupportprototypes M. Lenti
News from MARCON • Shipping at CERN ofall the mirrors: end of 2010 – beginningof 2011 • 4 dummysegmentsorderedtobeshaped and drilledas the mirrors (withoutanyopticalthreatment) forourtesting M.Lenti
Encoders NANOS InstrumentsGmbH EncodersdevelopedforPiezoMotor Twopiecesordered M.Lenti
Leaf Springs piezo • Full prototyperealized • “leafsprings”: mirrorhungthroughtwoholes • Mirrormovementaround x and y axis • pulled at 0 and 90 degrees • Mirrorweight: counterbalanceforverticalmovement • Leafsprings: counterbalanceforhorizontalmovement • Piezo-motor (final) used • 0.25 mm thickaluminiumribbon (directtraction, no 90 degdeviation); l=250mm piezo dowel dowel dowels Leafsprings piezo dowel M.Lenti
LeafSpringPrototype • For the horizontal plane (actuated by the leaf spring) the "zero" with the ribbon mounted was with a 12 mrad angle deviation with respect to the "free" situation(no horiz ribbon fixed). • I measured this both from the displacement at the ribbon fixation point and from the displacement of the laser spot on the photodiode. • The force to be exerted to bring all the stuff in the horiz. "zero" position is 60 g (or 0.6 N) measured with a dynamometer; the force is roughly linear with the observed displacement of the laser spot on the photodiode. • Use both an aluminum hexagon and a true glass mirror (pre-series mirror are with two holes in the back, lacking the central one) • Reduce step size by a factor 5 w.r.t. last meeting M.Lenti
LeafSpringPrototype Fromonepointto the next: 20 microstepmovementsof the Piezo (6.25 μm) Aluminumhexagon Glass mirror Spot position on the Photodiode 65 μm 65 μm 50μrad 50μrad 50μrad 50μrad Aluminumhexagon dist. Mirror-phtdiode: 700 mm Glass Mirror Dist. Mirror-phtdiode: 770 mm M.Lenti
Single DowelPrototype • Put the actuating ribbons “parallel” • “twist” the actuating ribbons (90 degree from the segment to the piezo) • Use a third ribbon for θZstabilization • Reduce stepsizeby a factor 5 M.Lenti
Single dowel piezo piezo • Full prototyperealized • “single dowel”: mirrorhung at the center • Mirrormovementaround u and v axis (insteadof x and y) • pulled at ±45 degrees (axisdecoupling) • Mirrorweight: counterbalanceforbothmovements • Piezo-motor (final) used • 0.25 mm thickaluminiumribbon (directtraction, no 90 degdeviation), 13 mm wide dowel dowel stabilizer piezo dowel M.Lenti
Ribbons are parallel Twistedribbon Twistedribbon Single Dowel The stabilizerribbonisfixed on the bottom corner of the Hexagon and at 500 mm on the right (availablealso on the left butnotused) Actuatingribbonsjoints on the Hexagonmadehorizontalusing a level fixed free fixed θZstabilizer θZstabilizer θZstabilizer M.Lenti
Single dowelprototype Fromonepointto the next: 20 microstepmovementsof the Piezo (6.25 μm) Piezoribbon joint on the hexagon: 300 mm from the dowel 6.25 μm/300 mm = 21μrad 16.11.2010 17.11.2010 Aluminumhexagon 65 μm 65 μm 50μrad 50μrad 50μrad 50μrad Spot position on the Photodiode Aluminumhexagon: dist. Mirror-phtdiode: 700 mm 40 μm on the photodiode 0.5*40 μm/700 mm = 28 μrad M.Lenti
Conclusions • Bothapproaches (leafsprings and single dowel) tested • Twoencodersordered • 4 Dummyglassmirrorsordered M.Lenti