  The eXTP (enhanced X-ray Timing and Polarimetry) mission is a major project
of the Chinese Academy of Sciences (CAS) and China National Space
Administration (CNSA) currently performing an extended phase A study and
proposed for a launch by 2025 in a low-earth orbit. The eXTP scientific payload
envisages a suite of instruments (Spectroscopy Focusing Array, Polarimetry
Focusing Array, Large Area Detector and Wide Field Monitor) offering
unprecedented simultaneous wide-band X-ray spectral, timing and polarimetry
sensitivity. A large European consortium is contributing to the eXTP study and
it is expected to provide key hardware elements, including a Large Area
Detector (LAD). The LAD instrument for eXTP is based on the design originally
proposed for the LOFT mission within the ESA context. The eXTP/LAD envisages a
deployed 3.4 m2 effective area in the 2-30 keV energy range, achieved through
the technology of the large-area Silicon Drift Detectors - offering a spectral
resolution of up to 200 eV FWHM at 6 keV - and of capillary plate collimators -
limiting the field of view to about 1 degree. In this paper we provide an
overview of the LAD instrument design, including new elements with respect to
the earlier LOFT configuration.
