FCAL Collaboration Meeting

1
LumiCal displacement measurement present status

• Wojciech Wierba INP PAN
• Jerzy Zachorowski UJ
• Wojciech Slominski UJ
• Leszek Zawiejski INP PAN
• Krzysztof Oliwa INP PAN
• Michal Karbowiak

2
Present setup single 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

3
Single beam setup layout
4
Single beam measurement results I
Y position
Difference beetween points µm
X position
X position
Camera has been translated in 50 µm 2 µm
(estimated error) steps
5
Single beam measurement results II
Y position
Difference between points µm
Difference between points µm
X position
X position
Camera has been translated in 50 µm 2 µm
(estimated error) steps
6
XYZ displacement measurement with two beams
Two laser beams (one not perpendicular to the
sensor) allows us to measure XYZ translation in
one sensor
7
Setup with two beams
8
Z translation of the camera
X and Y position are constant The angle between
two beams is 30
Z 0 µm
Z 250 µm
Z 500 µm
Z 750 µm
Z 1000 µm
Z 1250 µm
Z 1500 µm
9
Proposed setup with two beams and prism splitter
10
Readout electronics for CCD Prototype
11
Readout electronics for CCDanalog part
12
Readout electronics for CCD digital part
13
Conclusions

• The XY position measurement method with single
  beam has the accuracy better than a few
  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,
  results soon

14
Next steps

• New lasers with aspherical lenses better spot
• Beam splitter with half transparent mirror
  designed, not ordered yet
• Setup with two lasers better reliability
• Improvement of algorithm to determine centre of
  two spots
• Discussion on possible errors
• More compact prototype in progress
• Independent measurement of XYZ translations
  Renishaw industrial system (0.1 µm resolution)
• Stability tests