tpc meeting, cern, 17-18 january 2003børge svane nielsen, nbi1 status of laser system tpc meeting,...
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TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 1
Status of laser systemStatus of laser system
TPC meeting, CERN, 17-18 January 2003Børge Svane Nielsen
Niels Bohr Institute
Work since September 2002 Micro-mirror status Mirror support rings status Assembly of laser rods Optics and mechanics on end-plates
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 2
Laser system principleLaser system principle
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 3
Micromirror productionMicromirror production
All 60 bundles produced and delivered in September 2002, but problems with mirror surface quality and mechanical precision preliminary: 46 accepted based on surface quality most of these will be accepted after being
mechanically improved at NBI
additional 20 bundles in production in Moscow
reflecting surfaces
brass cup
mechanical reference surface
Micromirror bundle
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 4
Mirror surfaces (1)Mirror surfaces (1)
Looked at allmirrors inmicroscope.
Example:bundle 18+19
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 5
Mirror surfaces (2)Mirror surfaces (2)Looked at allmirror reflectionsafter 2.5 m.
Example:bundle 18+19
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 6
Mirror surfaces (3)Mirror surfaces (3)Analysed allmirror reflectionprofilesafter 2.5 m.
Example:bundle 18+19
Rejectedbadreflections
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 7
Mirror reflectancesMirror reflectances
Acceptance level: 150 (arbitrary units)
Preliminary accepted bundles (based on reflectance and image quality): 46 bundles out of 61 received
Amplitudes of profiles on previous slide:
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 8
Angles measurement (1)Angles measurement (1)
and angles of all micromirror faces measured by goniometer in Moscow
0.0014 (5 arc sec)
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 9
Angles measurement (2)Angles measurement (2)
However: reference surface not good bundle not fixed to support in reproducible way
only relative angles any good from this measurement
Reference surface has beenturned off in NBI workshop toprovide good surface
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 10
Angle re-calculationAngle re-calculation
Moreover: re-calculation of angles to take into account offset centres of 7 mirrors fail to use actual geometry of each bundle individual angles not correct
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 11
Angles measurement @ NBI
Angles measurement @ NBI
All mirror angles have been re-measuredat NBI, using laser beam setup-up.
Check measurement in progress
Estimated precision: 0.5 mrad (2 arc min) 0.5 mrad (2 arc min)
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 12
Angles measurementsAngles measurements
Mean = -0.08Sigma = 0.51
Mean = -0.29Sigma = 0.94
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 13
Linear measurementsLinear measurements
L
Mean = -0.23 mmSigma = 0.57 mm
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 14
Mirror support ringsMirror support rings
NBI workshop: 50 mirror support rings ready
All rings produced at NBI
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 15
Micromirror positionsMicromirror positions
Micromirror positions as seen by laser beam:
Near end-plates Near central electrode
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 16
Micromirror z positionsMicromirror z positions
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 17
Rod gluingRod gluing
1. Drill holes in short rods2. Mount mirror bundles in support rings.
3. Glue mirror support rings onto short rods. Theta alignment guaranteed by jig + machined surface
4. Glue short rods into full length rods. Phi alignment adjusted during gluing
5. Measurements on final rod possible before installation.
Foreseen in February-March.Details to be discussed next week.
TPC meeting, CERN, 17-18 January 2003 Børge Svane Nielsen, NBI 18
Optics and mechanics on end-plates and laser hutOptics and mechanics on end-plates and laser hut
Design in progress on opto-mechanical supports on end-plates:
Prism holder:
Prototypes to be constructed in NBI workshop
Laserbeam
Market survey on optical components for end-plates ongoing
Piezo-electric adjustment system from New Focus on order