XMM-Newton Users Handbook

3.3.7.3 EPIC Detector Noise

The dark currents of both types of EPIC CCD are negligible sources of background noise under nominal operating conditions (especially above 250 eV for the pn camera).

In MOS there are low level `flickerings' of a small number of pixels at an occurrence rate $< 1\%$. In pn occasionally (mainly during high particle background) the offset calculation leads in some pixels to a slight underestimate of the offset, which can result in blocks of approx. $4\times 4$ pixels with enhanced low energy signal.