Status of the ITS Alignment Monitoring System First results By Bjørn S. Nilsen The Ohio State University

Outline ITS and ITSAMS Geometry Camera Sport measurements Camera Calibration ITSAMS raw measurements ITS geometry effects?

Camera spot analysis Camera exposure… set for best image. 25 images taken in series Image smoothing to remove intensity anomalies –Ring centers found for a series of intensity thresholds. –Remove clearly anomalies centers Return Mean center and RMS. Means & errors computed from all 25 images

Camera Resolution Pixels Camera 0, RMSx=7.39±0.18, RMSy=7.48±0.18. Camera 1, RMSx=1.91±0.04, RMSy=1.76±0.04. Camera 3, RMSx=7.52±0.24, RMSy=5.96±0.19.

Image Centers

Calibration Data taken from Test-bench setup Image centers used old algorithm Still some problems with test-bench setup

Image location Data with L3 on in solid markers Camera center at 0,0.

1/29/2008W. Riegler TB Presentation In order to explain the vertical movement of the front absorber nose by 2.4mm, the top fixation point of the FASS would have to move by d=3.7mm. It seemed very improbable that the heavy magnet crown, that the FASS is attached to, is moving at all. L3 Magnet Tests, Frontabsorber Movement 8

1/29/2008W. Riegler TB Presentation Beampipe on ITS rail Lift beampipe (ITS) before TPC movement Beampipe (ITS) hanging on TPC +1 TRD, +8 TOF  1.5*9= 14T  2.3mm expected mm B-Field tests 0.17 T 0 T 0.17 T 0.5 T 0 T 0.5 T0.5 T + dipole 0 T +1 TOF Central Beampipe vs. FA 9 ITSAMS Installed/aligned ITSAMS Realigned March

Spot position By day Clearly spot position shifted when L3 field is on. Timing correlation not 100%. images (file dates), Magnet (dcs data base).

Top View Side View Many Cables ITSAMS Mirrors

IT’S A-Side View from Mirror 0 View of Mirror 0 mounting

ITS C-side

Stress free Mounting

ITS mounting - 3 point mount - Stress Free

Status Low Voltage on USB hub improved –Better reliability of camera communications Low Voltage IP address conflict fixed ITSAMS control system still improving –Automation of image taking and analysis to come –Computation of ITS movement being debugged. Wednesday L3 magnet on, run ITSAMS

Spot Missing Camera 2 Camera 0 Camera 1 Camera 3