A novel single-photon detector based on a vacuum tube with transmission photocathode, microchannel plates and the Timepix4 ASIC used as read-out anode is presented.

 

This detector is designed to detect up to 1 billion photons per second over a 7 cm^2 active area, achieving simultaneously position and timing resolutions of 5-10 microns and 50-100 ps, respectively. Comprising approximately 230,000 pixels equipped with both analog and digital front-end electronics, the Timepix4 ASIC allows to perform measurements using a data-driven architecture with data transmission rates up to 160 Gb/s. Configuration and read-out of the Timepix4 are controlled by custom FPGA-based external electronics and software framework. 

 

Initial characterisation of the Timepix4 ASIC bump-bonded to a 100-micron thick n-on-p silicon sensor, illuminated by an infrared pulsed picosecond laser, demonstrated a timing resolution of 110 ps per single pixel hit, after frequency calibration and time-walk correction. This resolution improves to below 50 ps when considering pixel clusters.

 

The first hybrid photodetector prototypes have been recently produced by Hamamatsu Photonics, using different combinations of microchannel plate stacks and end-spoiling depths. Their initial characterisation will be presented, including dark count rate, gain, spatial and timing resolution measurements, performed in the lab and in a test-beam campaign at the CERN SPS H8 extracted beam-line.