Special colloquium: "Development of a vacuum-based single-photon imaging detector" by Massimiliano Fiorini (INFN and University of Ferrara, Italy)

Thursday 7 Mar 2019, 14:00 → 15:00 Europe/Amsterdam

H331 (Nikhef)

The concept of a single-photon imager capable of detecting up to 109 photons per second with simultaneous measurement of position (5-10 µm resolution) and time (few tens of picosecond resolution) for each individual photon over an active area of 7 cm2 is presented. The detector is based on a “hybrid” concept: a vacuum tube, with a transparent input window on which a suitable photocathode material is deposited, a micro-channel plate and a pixelated read-out anode based on the Timepix4 ASIC, designed in 65 nm CMOS technology in the frame of the Medipix4 collaboration. Timepix4 is an array of 512x448 pixels, 55µmx55µm each, with an active area of 28mmx25mm. It features 50-70 e- equivalent noise charge, a maximum rate of about 1 Ghits/s, and allows to time-stamp leading-edge time and measure Time-over-Threshold (ToT) for each individual pixel. A weighted average of the cluster pixels position can be calculated using their ToT information, which would allow to reach 5-10 μm position resolution. The ToT information can also be used to correct for the leading-edge time-walk in each pixel, and a timing resolution of few tens of picosecond is expected per cluster. The detector will be highly compact: the front-end electronics is encapsulated inside the vacuum tube and allows local processing of the detector information, which is sent out of the tube in digital form. A flexible design is conceived, with electro-optical transceivers linking the ASIC to a FPGA-based board, placed far from the detector, for the exchange of configuration and the collection of event data. The FPGA will perform serial decoding and send the data directly to a PC for storage using fast serial data links. The figures of merit of this detector will open many important applications allowing significant advances in particle physics, life sciences, quantum optics or other emerging fields where the detection of single photons with excellent timing and position resolutions are simultaneously required.