Status of Test Beam

May 21, 2003 P. Nilsson, SPD General Meeting 1

Paul Nilsson, SPD General Meeting , May 21, 2003

Test Beam 2002 Analysis

Status of Test Beam

Report on the status of the offline analysis. Results from threshold, delay and bias scans.

Analysis

May 21, 2003 P. Nilsson, SPD General Meeting 2

Offline Analysis – Low Efficiency Problem?

The data desynchronization causing event shifts has been corrected for in software, yielding close to perfect results. The period of the apparent event shifts matched EXACTLY the scaler setting in the trigger card. The trigger card will be investigated as soon as possible.

May 21, 2003 P. Nilsson, SPD General Meeting 3

Offline Analysis – Current Status

• All necessary software/utilities developed

analyzeanalyze2htmlanalysis database

raw data to analyzed root treeroot tree to web pageprovides easy web access via test beam homepage

• Analyzed files include threshold, delay, bias and angle scans• Known problem with angle scans due to current alignment algorithm and big run sets (~2M events)• Only minor changes required for next test beam

http://alice1.web.cern.ch/alice1/testbeam2002/index.asp

May 21, 2003 P. Nilsson, SPD General Meeting 4

Offline Analysis – TB Analysis Webpage

Test Beam webcontains a subset of the analyzed files (more will be added as soon as they are processed)

May 21, 2003 P. Nilsson, SPD General Meeting 5

Offline Analysis – Sample Analysis Webpage

Efficiency vs. analysis parameter (e.g. delay)

X-Resolution vs. analysis parameter

Y-Resolution vs. analysis parameter

Residuals vs. event number

Average cluster size vs. analysis parameter

Cluster size distributions

Beam spots

Noisy pixel reports

File information

May 21, 2003 P. Nilsson, SPD General Meeting 6

Offline Analysis – Threshold ScansLadder chip (14/7, chip 1): Efficiency vs. PRE_VTH

May 21, 2003 P. Nilsson, SPD General Meeting 7

Offline Analysis – Threshold ScansLadder chip (14/7, chip 1): Resolutions vs. PRE_VTH

X-Resolution (long direction)Average resolution: 0.124973 ± 0.000470 mmResolution at max efficiency (98.766518%): 0.120588 ± 0.001438 mm (expected < 0.123 mm)

Y-Resolution (short direction)Average resolution = 0.014799 ± 0.000028 mm

Resolution at max efficiency (98.766518%): 0.013221 ± 0.000106 mm (expected < 0.0144 mm)

May 21, 2003 P. Nilsson, SPD General Meeting 8

Offline Analysis – Threshold Scans

Ladder chip (14/7, chip 1):Average cluster size vs. PRE_VTH

Ladder chip (14/7, chip 3):Average cluster size vs. PRE_VTH

May 21, 2003 P. Nilsson, SPD General Meeting 9

Offline Analysis – Delay ScansLadder chip (14/7): Efficiency vs. delay

~45 ns

May 21, 2003 P. Nilsson, SPD General Meeting 10

Offline Analysis – Delay ScansLadder chip (14/7): Resolutions vs. delay

X-Resolution (long direction)Average resolution: 0.108570 ± 0.000346Resolution at max efficiency (98.712952%): 0.107169 ± 0.001360 (expected < 0.123 mm)

Y-Resolution (short direction)Average resolution = 0.015157 ± 0.000036

Resolution at max efficiency (98.712952%): 0.014538 ± 0.000116 (expected < 0.0144 mm)

May 21, 2003 P. Nilsson, SPD General Meeting 11

Offline Analysis – Delay Scans

Ladder chip (14/7):Average cluster sizevs. delay

(Compare with efficiency vs. delay plot)

May 21, 2003 P. Nilsson, SPD General Meeting 12

Offline Analysis – Bias ScansLadder chip 3 (14/7): Efficiency vs. bias voltage

PRE_VTH = 185

PRE_VTH = 200

PRE_VTH = 220

May 21, 2003 P. Nilsson, SPD General Meeting 13

Offline Analysis – Bias ScansLadder chip (14/7, PRE_VTH = 220): Resolutions vs. bias

X-Resolution (long direction)Average resolution: 0.108831 ± 0.000473Resolution at max efficiency (98.998047%): 0.105374 ± 0.001371 (expected < 0.123 mm)

Y-Resolution (short direction)Average resolution = 0.014098 ± 0.000039

Resolution at max efficiency (98.998047%): 0.012712 ± 0.000094 (expected < 0.0144 mm)

May 21, 2003 P. Nilsson, SPD General Meeting 14

Offline Analysis – Bias Scans

PRE_VTH = 185

Ladder chip 3 (14/7): Average cluster size vs. bias voltage

PRE_VTH = 200

PRE_VTH = 220