1. Radiation damage effects CCD detectors
Marcel Dobber (KNMI)
Quintus Kleipool (KNMI)

2. Radiation damage effects CCD detectors
OMI on NASA’s EOS-Aura (launched 15 July 2004)
2 CCD detectors
CCD EEV 55
576 rows and 780 columns
additional read-out register with 814 columns
GOMOS on ESA’s ENVISAT (launched 1 March 2002)
4 CCD detectors
CCD EEV 2610 with 2*143 rows and 1353 columns
OSIRIS on ODIN (launched 20 February 2001)
CCD EEV model CCD 26
1353 x 286 elements

3. CCD detectors
GOMOS
OMI

4. OMI aluminium shielding
10 kg additional aluminium shielding
average thickness 29 mm
no additional shielding for GOMOS and OSIRIS

5. Trapped proton radiation damage
Damage caused by high energetic protons (> 10 MeV) trapped in the magnetic field of the earth.

6. Analysis Estimate number of hit pixels by:
counting permanent spikes with permanently increased dark current.
works well if unbinned dark spectra are available (OMI and OSIRIS), not for GOMOS.
calculate normalised time-difference histograms
works well for both unbinned (OMI, OSIRIS) and binned cases (OMI, GOMOS).

7. Analysis
OMI histogram time difference

8. OMI, binning factor 7, histogram time difference.

9. OMI count unbinned hot pixels.

10. Analysis
GOMOS histogram
time difference.

11. OSIRIS count unbinned hot pixels.

12. OSIRIS histogram time difference method.

13. Conclusions sofar Different time periods vs solar cycle.
OMI on-ground testing almost 100% damaged, hence >
Shielding high- and low-energetic protons vs secondaries (neutrons).
Counted hot pixels, assessment of impact on hot pixels (increase dark current, RTS, etc.) is much more difficult.