Single-shot MHz velocity-map-imaging using two Timepix3 cameras

TL;DR

This paper showcases the use of Timepix3 detectors in a velocity-map-imaging spectrometer to capture full 3D charged particle momentum at high repetition rates, enabling advanced imaging with high resolution.

Contribution

Introduction of Timepix3-based detectors for single-shot, high-repetition-rate velocity-map imaging with enhanced spatial and temporal resolution.

Findings

Successful measurement of N₂ fragmentation at 250 kHz with sub-pixel resolution.

Single-shot imaging of He photoelectrons at 1 MHz repetition rate.

Overcoming limitations of standard cameras for high-rate, high-resolution imaging.

Abstract

We demonstrate the application of event-driven Timepix3-based detectors in combination with a double-sided velocity-map-imaging spectrometer to record the full 3D momentum of charged particles at the free-electron-laser facility FLASH. We measured the XUV induced fragmentation of $\text{N}_2$ using 250 kHz FLASH bursts with sub-pixel spatial resolution and up to 1.7~ns temporal resolution for photoelectrons. To further demonstrate the capabilities of this camera at even higher repetition rates we measured single-shot images of He($1s$) photoelectrons for bursts with a repetition rate of 1 MHz. Overall, with the Timepix3 camera we overcome limitations of standard-camera technology for advanced-imaging experiments with requirements on high event-rates and high spatio-temporal resolution.