Detective Quantum Efficiency of the Timepix4 Hybrid Pixel Detector and its Application to Parallel-Beam Diffraction

TL;DR

This paper measures the detective quantum efficiency of the Timepix4 detector in TEM, demonstrating high DQE at zero frequency and its capability to detect weak diffraction signals at 200 kV.

Contribution

It provides the first detailed DQE and NNPS measurements of Timepix4 in TEM and showcases its application in detecting weak diffraction signals.

Findings

Zero-frequency DQE exceeds 0.9 at 100 kV and 200 kV.

DQE remains above 0.2 at Nyquist frequency at 100 kV.

Timepix4 detects weak diffraction beyond 75 mrad at 200 kV.

Abstract

The detective quantum efficiency (DQE) and normalised noise power spectrum (NNPS) of the Timepix4 hybrid pixel detector in event-driven mode in TEM have been measured at 100 kV and 200 kV. In a raw data readout mode, the zero-frequency DQE exceeds 0.9 at both 100 kV and 200 kV. At the Nyquist frequency, the DQE remains above 0.2 at 100 kV but drops close to zero at 200 kV. Initial parallel-beam diffraction data from a polycrystalline gold nanoparticle sample is reported which shows that at 200 kV Timepix4 can detect weak diffracted information beyond a 75 mrad half-angle.