[continues from 4.5]

4.6 Detector quantum efficiency

The term epsilon is made of two terms corresponding to the two regions of the detector: the drift region where the bulk of the conversion of X-rays into electrons occur, and the scintillation region, where residual conversion of some X-rays may occur.
In both cases the energy dependency is modelled through the Xe absorption cross section (computed from atomic coefficients hardcoded in the programs).

4.6.1 Drift region

The calibration parameters of the drift region in the cell are currently the same for all three MECS units.

The values of these parameters for all three MECS units are stored in file cell.coeff and are:

Fig. 4.6.1-I : absorption efficiency in the drift region (click on figure to expand Y scale)

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