On the Single-Photon-Counting (SPC) modes of imaging using an XFEL source

TL;DR

This paper evaluates the feasibility of single-photon-counting modes in high-efficiency, high-frame-rate XFEL imaging, comparing detector architectures and proposing multilayer 3D detectors for advanced X-ray detection.

Contribution

It introduces the analysis of multilayer 3D detector architecture as a novel approach to achieve SPC modes for XFEL imaging.

Findings

Si can potentially meet efficiency and frame rate requirements in SPC mode.

Multilayer 3D detector architecture offers advantages over traditional 2D structures.

Thin film cameras with onboard ASICs are promising for initial implementation.

Abstract

The requirements to achieve high detection efficiency (above 50\%) and gigahertz (GHz) frame rate for the proposed 42-keV X-ray free-electron laser (XFEL) at Los Alamos are summarized. Direct detection scenarios using C (diamond), Si, Ge and GaAs semiconductor sensors are analyzed. Single-photon counting (SPC) mode and weak SPC mode using Si can potentially meet the efficiency and frame rate requirements and be useful to both photoelectric absorption and Compton physics as the photon energy increases. Multilayer three-dimensional (3D) detector architecture, as a possible means to realize SPC modes, is compared with the widely used two-dimensional (2D) hybrid planar electrode structure and 3D deeply entrenched electrode architecture. Demonstration of thin film cameras less than 100-$\mu$m thick with onboard thin ASICs could be an initial step to realize multilayer 3D detectors and SPC modes for XFELs.