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Status of laser system. 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 Niels Bohr Institute. Laser system principle. Micromirror production.
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Status of laser system • 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 Niels Bohr Institute Børge Svane Nielsen, NBI
Laser system principle Børge Svane Nielsen, NBI
Micromirror 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 mechanical reference surface brass cup reflecting surfaces Micromirror bundle Børge Svane Nielsen, NBI
Mirror surfaces (1) Looked at all mirrors in microscope. Example: bundle 18+19 Børge Svane Nielsen, NBI
Mirror surfaces (2) Looked at all mirror reflections after 2.5 m. Example: bundle 18+19 Børge Svane Nielsen, NBI
Mirror surfaces (3) Analysed all mirror reflection profiles after 2.5 m. Example: bundle 18+19 Rejected bad reflections Børge Svane Nielsen, NBI
Mirror reflectances Amplitudes of profiles on previous slide: Acceptance level: 150 (arbitrary units) Preliminary accepted bundles (based on reflectance and image quality): 46 bundles out of 61 received Børge Svane Nielsen, NBI
Angles measurement (1) and angles of all micromirror faces measured by goniometer in Moscow 0.0014 (5 arc sec) Børge Svane Nielsen, NBI
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 been turned off in NBI workshop to provide good surface Børge Svane Nielsen, NBI
Angle 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 Børge Svane Nielsen, NBI
Angles measurement @ NBI All mirror angles have been re-measured at NBI, using laser beam setup-up. Check measurement in progress Estimated precision: 0.5 mrad (2 arc min) 0.5 mrad (2 arc min) Børge Svane Nielsen, NBI
Angles measurements Mean = -0.08 Sigma = 0.51 Mean = -0.29 Sigma = 0.94 Børge Svane Nielsen, NBI
Linear measurements Mean = -0.23 mm Sigma = 0.57 mm L Børge Svane Nielsen, NBI
Mirror support rings NBI workshop: 50 mirror support rings ready All rings produced at NBI Børge Svane Nielsen, NBI
Micromirror positions Micromirror positions as seen by laser beam: Near end-plates Near central electrode Børge Svane Nielsen, NBI
Micromirror z positions Børge Svane Nielsen, NBI
Rod gluing • Drill holes in short rods • Mount mirror bundles in support rings. • 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 • Measurements on final rod possible before installation. • Foreseen in February-March. • Details to be discussed next week. Børge Svane Nielsen, NBI
Optics and mechanics on end-plates and laser hut Market survey on optical components for end-plates ongoing Piezo-electric adjustment system from New Focus on order Design in progress on opto-mechanical supports on end-plates: Prism holder: Laser beam Prototypes to be constructed in NBI workshop Børge Svane Nielsen, NBI