1 / 20

Laser positioning system

This project discusses the design and implementation of a laser positioning system for aligning a calorimeter with the beam pipe. It includes proposed solutions for online measurement of sensor planes and discusses the accuracy of various measurement methods. The future steps for improvement and stability tests are also outlined.

georgiao
Télécharger la présentation

Laser positioning system

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Laser positioning system Status 17.10.2006 Wojciech Wierba, Krzysztof Oliwa, Leszek Zawiejski, Michał Karbowiak (diploma student) Institute of Nuclear Physics PAN Cracow, Poland FCAL Workshop 17.10.2006 München

  2. Content • Laser positioning system for calorimeter with respect to the beam pipe • Proposed solutions for the online measurement of the sensor planes

  3. Present setup – dual laser beam • BW camera DX1-1394a from Kappa company 640 x 480 with Sony ICX424AL (70€) sensor 7.4 μm x 7.4 μm unit cell size • Laser module LDM635/1LT from Roithner Lasertechnik • ThorLabs ½” travel translation stage MT3 with micrometers (smallest div. 10 μm) • Neutral density filters ND2 • Half transparent mirror • New support for mirrors and filters • Renishaw RG24 optical head (0,1 µm resolution) to control movement of the camera

  4. XYZ displacement measurement with two beams Two laser beams (one perpendicular, second with 45˚ angle to the sensor plane) allows us to measure XYZ translation in one sensor

  5. Setup with two beams

  6. XY measurement Difference between points [μm] Difference between points [μm] Y position X position Camera has been translated in 50 μm ± 2 μm (estimated error) steps

  7. Z displacement measurement (3 different algorithms)

  8. Proposed setup with two beams and prism splitter

  9. Readout electronics for CCD Prototype

  10. Readout electronics for CCDanalog part

  11. Readout electronics for CCD digital part

  12. Conclusions • The XY position measurement method with single beam has the accuracy in order of ~2 micrometers • The different XY algorithm and new measurements shows similar results • The XYZ position measurement with two beams looks promising, a new algorithm has been developed, the accuracy is in order of ~2 µm in XY and ~4 µm in Z direction • Both XY & Z uncertainties are in the same order as estimated accuracy of a micrometric screws

  13. Next steps • New lasers with aspherical lenses – better spot. • Beam splitter with half transparent mirror – designed, not ordered yet (probably we will skip it because of manufacturing problems) • Setup with two lasers – better reliability • Improvement of algorithm to determine centre of two spots (in progress) • Discussion on possible errors • More compact prototype – in progress (new person involved) • Independent measurement of XYZ translations – Renishaw industrial system (0.1 μm resolution). We are waiting (will come in a few days) for the PC card to read out the signals from the Renishaw RG24 optical head. • Stability tests

  14. Online alignment of sensor planes • One laser beam lighting the transparent position sensors placed on each sensors plane • Individual laser positioning system for each (or only a few) sensor plane • Spanned wire going through the holes in sensor planes working as an antenna and pickup electrodes to measure the position

  15. Transparent position sensors • Special transparent sensors • Problems with reflections • Degradation of the beam shape for deeper planes

  16. Idyvidual positioning system for each plane • Standard CMOS or CCD sensors • Similar electronics as in position system for calorimeter • More reliable • More lasers • More space necessary

  17. Spanned wire alignment • Active during time slots between trains • Possible interferences • Accuracy up to ~0,5 µm • Quite simple electronics • Need 4 coax cables for each plane

More Related