XMM-Newton Users Handbook

3.3.1.2 EPIC pn chip geometry

The heart of the pn camera is a single Silicon wafer with 12 CCD chips integrated. The pn chip array numbering scheme, the individual chip coordinate frames and the directions of the detector coordinates are displayed in Fig. 22.

Figure 22: The layout of the EPIC pn camera as presented in SAS. The orientation of the RAWX/RAWY (CCD specific) and of the DETX/DETY axes are shown, to highlight that the RGS dispersion axes are parallel within spacecraft physical coordinates. The readout CAMEX of each CCD is located at RAWY = 0, i.e. at the top (for CCDs 1 - 6) or bottom (for CCDs 7 - 12) of the displayed array. In the upper left corner, the orientation of the celestial North and East axes is displayed for an assumed position angle (PA) of 30$^{\circ }$.