Test-beam Results for the CMS Forward Pixel Detector Carsten Rott Daniela Bortoletto, Gino Bolla, Amitava Roy Purdue University 28 April 2001
Test-beam Results for the CMS Forward Pixel Detector Carsten Rott Daniela Bortoletto Gino Bolla Amitava Roy Purdue University 28 April 2001
Pixels/blade 24 Blades/disk The CMS Detector APS 2001 C. Rott Barrel + Forward Pixel Disks FPIX-Disk
The Pixel Detector 150 m x m pixel thickness 270 m 22x30 pixel array rad. hard DMILL ROC APS 2001 C. Rott
Telescope Beam Si-Strips vertical Si-Strips horizontal Scint. Counters X/Y-Fibers 1mm Dia. few mm 2 Extrapolated track x = 2.0 m y = 3.6 m Pixel Detector and Repeater Card APS 2001 C. Rott 250GeV/c pion beam Repeater card can be rotated Can trigger on region as. small as 1mm 2
Charge sharing comparison Charge sharing between rows (rotated by 20 o ) Charge sharing between rows (not rotated) 150 m APS 2001 C. Rott PH is 12bit ADC value Charge sharing is increased by rotating the sensor Charge sharing can be used to improve the resolution
distribution Position correction curve APS 2001 C. Rott is the difference of the fraction of charge deposited in the neighboring pixel A is a normalization factor vs position ( 20 o rotation angle)
Resolution Resolution in micron between rows (rotated by 20 o ) Resolution in micron between rows (not rotated) APS 2001 C. Rott
Resolution APS 2001 C. Rott 0 0 rotation 20 0 rotation Highest resolution for large charge sharing and hits in between pixel
Signal height: Noise: Signal to noise ratio of 60 S/N and Efficiency APS 2001 C. Rott An absolute efficiency could not be measured because of a time stamp problem. A strong correlation between tracked position and pixel hit position, suggests high efficiency.
Conclusions Charge sharing can improve the resolution Resolution at 20 0 rotation m Resolution at 0 0 rotation m Resolution is position dependent S/N = 60 High efficiency APS 2001 C. Rott