FIRST RESULTS OF MONITORING OF THE ILLUMINATOR SEQUENCE DATA Introduction. ------------- From the new version of SPL we get the LIPD file, which contains the Illuminator Sequence data in a format more suitable to perform analysis than the previous LILL file. For this reason the monitoring of these data is re-started. Both dark-current and flash measurements taken during the sequence are analysed, using the AOT data obtained in calibration revolutions. Data from different revolutions can be put all togheter because the monitoring of the flash sequences at the handover shows that there is no drift during the time of the mission. Data Processing. ---------------- All the observations performed with AOT in routine-phase calibration revolutions were reprocessed with the new version of SPL and the LIPD files were copied in the directory disk$lwsscratch:[etommasi] (TBC). They correspond to 242 observations of different sources, taken in 45 different revolutions, with different AOTs. An IDL code was implemented that, for each file, performs the following steps: - reads the LIPD file - records the initial ITK of the observation - selects only the data for the opaque flashes (up to revolution 336 we had open flashes in the middle of long observations) - selects the background/flash data ramps - computes the mean and the sigma values of the selected ramps and discards the points out of 3*sigma from the median - computes the mean and the sigma values of the remaining ramps - flags the data to distinguish the ones taken with the new scheme from the ones taken with the old scheme At the end, initial ITK, median, sigma and flag from all the files are recorded into an IDL structure. Results for flash data. ----------------------- Plotting the mean values of the flash data versus ITK shows the behaviour of the responsivity of the detectors during the revolution time (see for example SW1, SW2 and LW5 in Fig.1a-c). Note that at about ITK=6*10^8 the hand-over and the curing of the detectors take place. First of all, in the plots we can see the difference between the old and the new scheme both in level and in the error bars (in the new scheme we take more ramps so the uncertainty is less). For SW1 and SW2 we can also recognize the observations made with a lower bias level (up to revolution 150). For all the detectors, there are two low outliers which are two observations taken with lower bias in rev217 and 223). Note also that LW3 and LW4 were often saturated with the level of the old scheme. The drift in the responsivity is apparent for all the detectors, except SW1. Further analysis on these plots shows that there are other outliers, that could be indications of possible problems in the observations; for example 5 observations in revolution 453 (3 before and 2 after the handover) have higher values of photocurrent. Results for background data. --------------------------- Plotting the mean values of the background data versus ITK (see for example SW2 and LW3 in Fig.2a-b), first of all we can compare the opacity of the two FP misallined positions: as in observations of bright sources taken with the new scheme the level for the SW detectors is definitevely higher, we have the confirmation that for these detectors the FPL position is less opaque than the FPS one. Even if this difference is very small compared with the total flux of the source (see also note LWS/IDT/N/0038.1 and addendum) we should worry about this. A drift during revolution could also be seen for these data in some detectors. Work is in progress to understand if the linear fits shown in Fig.3 are realible.