The Large Area Detector onboard the eXTP mission

TL;DR

The paper describes the design and key features of the Large Area Detector (LAD) for the eXTP mission, highlighting its large effective area, spectral resolution, and technological innovations for X-ray astronomy.

Contribution

It presents an overview of the LAD instrument design, including new elements compared to the earlier LOFT concept, for the upcoming eXTP mission.

Findings

Effective area of 3.4 m² in 2-30 keV range

Spectral resolution up to 200 eV FWHM at 6 keV

Innovative use of Silicon Drift Detectors and capillary plate collimators

Abstract

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.