  A new, modular toolkit for creating simulations of 2D X-ray pixel detectors,
X-CSIT (X-ray Camera SImulation Toolkit), is being developed. The toolkit uses
three sequential simulations of detector processes which model photon
interactions, electron charge cloud spreading with a high charge density plasma
model and common electronic components used in detector readout. In addition,
because of the wide variety in pixel detector design, X-CSIT has been designed
as a modular platform so that existing functions can be modified or additional
functionality added if the specific design of a detector demands it. X-CSIT
will be used to create simulations of the detectors at the European XFEL,
including three bespoke 2D detectors: the Adaptive Gain Integrating Pixel
Detector (AGIPD), Large Pixel Detector (LPD) and DePFET Sensor with Signal
Compression (DSSC). These simulations will be used by the detector group at the
European XFEL for detector characterisation and calibration. For this purpose,
X-CSIT has been integrated into the European XFEL's software framework, Karabo.
This will further make it available to users to aid with the planning of
experiments and analysis of data. In addition, X-CSIT will be released as a
standalone, open source version for other users, collaborations and groups
intending to create simulations of their own detectors.
