Further measurements of random telegraph signals in proton irradiated CCDs

The probability/incident proton for creation of a defect in a charge-coupled device (CCD) which shows dark current random telegraph signal (RTS) behavior has been measured for energies of 1.5, 10 and 46 MeV. The probability was found to be proportional to the non-ionizing energy loss (NIEL) for elastic collisions. Plots of RTS probability versus mean dark current indicate a correlation with the amount of field enhanced emission. If a pixel already has a defect showing field enhanced emission, it is more likely to show RTS effects. The amplitudes themselves are not correlated with the degree of field enhanced emission. An alternative to the bulk metastable defect model is proposed, based on the reorientation of the phosphorus-vacancy center in a high electric field.