CCD diagnostics and 04122003 data

1
CCD diagnostics and 04/12/2003 data

• Talk outline
• Introduction to CCD use in PETRA laserwire
• Readout and software
• Readout problems
• Analysis of images
• Results for scans of 04/12/2003
• Summary of results
• Near term future work
• Summary

Stewart Boogert (UCL) Laserwire meeting, DESY,
26/02/2004
2
CCD Diagnostics

• System
• 2 cameras
• Pre/post IP
• Image IP laser spot
• Basler A302f
• Camera specifications
• Monochrome
• 8bit ADC
• 780-582 resolution
• 8.3 ?m pixel pitch
• 30 fps frame rate
• Shutter/Gain/Brightness control
• Triggered operation
• Firewire
• External line
• Small footprint

3
Readout software

• Firewire
• Digital
• No readout card required or grabber
• BCAM driver simple API
• Cable lengths (lt10m)
• Readout
• C library
• Simple to use
• Tied to Microsoft
• No problem now (W2000/XP)
• Multiple file formats (ascii, bmp)
• MFC based windows executable
• Fast (25-30 fps)
• See images directly as DAQ runs
• Upgrade for next run
• Triggered image acquisition
• Multiple cameras
• Analysis included

4
Readout problems

• Trigger
• Laser 30 Hz CCD 30 fps
• Empty frames
• Partial images
• Recently found
• Only occurs in 1st scan
• Cause unknown
• Laser damage
• Care must be taken not to damage devices
• Filtering
• Currently use OD 2-5 ND filters
• Reflection reduction in intensity

5
CCD image analysis

• Analysis procedure
• Delete burn marks
• Apply threshold (gt 13)
• Project x y
• Mean/rms/fit projections
• Pixel error constant in fits
• Average over all images for a scan point
• Important to remember
• Area of interest (AoI)
• Fits and mean/RMS calculation
• None implemented here
• Errors on pixel values
• Constant?
• Dependent on signal?
• Propagation through to background subtraction

6
CCD Background

• Analysis of blank images
• Pixel histograms
• Camera1 (post IP) very noisy
• Partly due to damage
• Shutter
• Ambient light noise should be reduced
• Post IP camera very noisy.
• Could be from damage
• Radiation
• Source of background
• Ambient light
• Diffuse laser reflections?
• Electronics noise
• Thermal?
• Accelerator induced electronics noise?

7
CCD analysis Low Current Scan (camera 1)

• Data taking
• 10-30 frames/camera/scan point before calorimeter
  measurement

8
CCD analysis Low Current Scan (camera 2)

• Data taking
• 10-30 frames/camera/scan point before calorimeter
  measurement

9
CCD analysis High Current Scan (camera 1)

• Data taking
• 50 frames/camera/scan point before calorimeter
  measurement
• 30 frames not enough

10
CCD analysis High Current Scan (camera 2)

• Data taking
• 50 frames/camera/scan point before calorimeter
  measurement

11
CCD calibration summary

• Summary of CCD/scanner results
• Mean mean position / scanner voltage
• Fit-? Gaussian mean position / scanner voltage
• RMS average RMS
• Fit-? average Gaussian width
• Calibration
• Fit and simple calculation consistent
• Low and high current scans are not consistent!

12
Future work

• Analysis
• Gain/Brightness tuning loop
• Online analysis fitting etc
• Trigger
• 100 filled images
• Camera from RHUL, kitted out PC _at_ UCL
• Cooling/Radiation
• Temperature monitoring
• Investigate cooling options
• Background
• Background levels with/without
• PETRA beam
• Laser
• Area of Interest
• Calibration
• CCD to chamber centre

13
CCD Calibration _at_ RHUL

• CCD Calibration
• Optical calibration
• SB, Gary Boorman, Stephen Malton, John Carter.
• Setup
• HeNe laser
• Knife edge scan at IP focus measure
• Position (if possible)
• Width
• Then measure with CCD
• Hardware on order
• CMOS A600hd camera
• Optical components
• ADC card

14
Short term developments

• Trigger
• Signal generator
• Pulse generator with delay (trigger signal)
• LED (for fake signal)
• Stephen Malton
• Software (triggered version is quite complicated)
• Testing
• Large increase in good CCD data factor 2-3
• Environment monitoring
• Damaged 2 cameras last year!
• Temperature
• Humidity
• Radiation
• Ambient light (background)
• Insert during next visit?

15
Longer term

• High speed scanning
• CMOS technology
• Basler A500
• 500 fps _at_ 1Mpixel
• 7000 fps maximum
• More radiation hard
• Even faster scanning with multiple laser pulses
  per
• Larger dynamic range
• Basler A302f
• 8 bit
• How about 12-16 bit output?
• Better signal to noise
• Basler A600hd
• Effective 16bit output _at_ VGA resolution
• 50 fps _at_ 8 bit
• 8 fps _at_ 16 bit

16
Summary

• First use of CCDs during scan
• Fit and simple calculation consistent
• Low and high current scans are not consistent!
• Much to be done
• Calibration
• Measurements soon (1 month)
• Analysis
• Implement in DAQ
• Software
• Being upgraded for
• Multiple camera grabbing
• Automatic camera parameter tuning
• Background
• Tests in PETRA with/without beam laser/electron
• Reliability
• Environment monitoring (discuss here)