Top: fractional charge loss curve for the AF8 device in row 3. The step increases are due to the two solar proton events. Bottom: similar to top, but for the RP CCD in CCD row 1. The effect of the solar events is so low for this CCD that it is barely visible (see text for further details). Also, it can be observed that the initial FPR is higher for this CCD than for the AF CCD shown on top. This is a trait common to all of the red CCDs relative to the AF/BP devices where the measured on-ground CTI is significantly higher. Interestingly, the opposite is the case for the serial register CTI where the red devices display more efficient transfer (see Sect. 4.4).