RGS long-term long-wavelength contamination monitor

Although contamination monitoring was introduced and vigorously pursued afterthe RGS and MOS were cooled in 2002 November, it is important to establish alongterm contamination monitor. The star zeta Puppis is an ideal target becauseof the exceptional strength of its NVI and NVII lines at about 25 and 30Arespectively. So far, XMM has not been able to detect any variability in thisstar above the few percent level. It is visible for 2 months every 6 months andfor this longterm programme, I propose a longer observation time than usedduring the immediate postcooling period, prefering instead the 60ks used forthe PV phase.* copied from prop 41258 to obtain PI data. Obs 1 copied from obs 13 of prop 15936 to obtain target data; Obs 8 and 12 used for EPIC eff area/offset (50 off) truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]