Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Development and characterization of hybrid MCP-PMT with embedded Timepix4 ASIC used as pixelated anode

Riccardo Bolzonella, Jerome Alozy, Rafael Ballabriga, Nicolò Vladi Biesuz, Michael Campbell, Viola Cavallini, Angelo Cotta Ramusino, Massimiliano Fiorini, Edoardo Franzoso, Marco Guarise, Xavi Llopart Cudie, Gabriele Romolini, Alessandro Saputi

TL;DR

This work addresses the need for a large-area, high-resolution single-photon detector by integrating a photocathode-MCP assembly with a Timepix4 ASIC as a pixelated anode in a vacuum tube. The Timepix4 provides ~230k pixels with 55 micrometer pitch and a 195 picosecond TDC, enabling data-driven readout at up to 160 Gb/s; calibrations include per-pixel threshold tuning and ToT response. Preliminary measurements yield per-pixel timing around 107 picoseconds and cluster timing around 33 picoseconds on silicon-sensor tests, while MCP-PMT prototypes show dark counts below ~30 Hz/cm^2 at high MCP bias and timing resolutions approaching 65 picoseconds for multi-pixel clusters. The results validate the hybrid MCP-PMT approach for high-rate photon imaging and indicate clear paths for optimization across MCP configurations and readout integration, with potential impact on RICH-type detectors and related high-energy physics applications.

Abstract

We present a novel single-photon detector based on a vacuum tube incorporating a photocathode, a microchannel plate (MCP), and a Timepix4 CMOS ASIC functioning as a pixelated anode. Designed to handle photon rates up to 1 billion per second across a 7 cm$^2$ active area, the detector achieves outstanding spatial and temporal resolutions of 5-10 $μ$m and below 50 ps r.m.s., respectively. The Timepix4 ASIC comprises approximately 230,000 pixels, each integrating analog and digital front-end electronics. This enables data-driven acquisition and supports data transmission rates up to 160 Gb/s. External FPGA-based electronics manage both configuration and readout. In order to test the timing performance of the Timepix4 ASIC we performed preliminary characterization of an assembly bonded to a 100 $μ$m thick n-on-p silicon sensor using a pulsed infrared laser, which demonstrated a per-pixel timing resolution of 110 ps, with cluster-based averaging methods improving to below 50 ps. Six prototype detectors incorporating different MCP stack configurations and end-spoiling depths were produced by Hamamatsu Photonics. We report on their characterization, including dark count rates, gain, and spatial and timing resolutions, assessed both in laboratory conditions and during a test-beam campaign at CERN's SPS facility.

Development and characterization of hybrid MCP-PMT with embedded Timepix4 ASIC used as pixelated anode

TL;DR

This work addresses the need for a large-area, high-resolution single-photon detector by integrating a photocathode-MCP assembly with a Timepix4 ASIC as a pixelated anode in a vacuum tube. The Timepix4 provides ~230k pixels with 55 micrometer pitch and a 195 picosecond TDC, enabling data-driven readout at up to 160 Gb/s; calibrations include per-pixel threshold tuning and ToT response. Preliminary measurements yield per-pixel timing around 107 picoseconds and cluster timing around 33 picoseconds on silicon-sensor tests, while MCP-PMT prototypes show dark counts below ~30 Hz/cm^2 at high MCP bias and timing resolutions approaching 65 picoseconds for multi-pixel clusters. The results validate the hybrid MCP-PMT approach for high-rate photon imaging and indicate clear paths for optimization across MCP configurations and readout integration, with potential impact on RICH-type detectors and related high-energy physics applications.

Abstract

We present a novel single-photon detector based on a vacuum tube incorporating a photocathode, a microchannel plate (MCP), and a Timepix4 CMOS ASIC functioning as a pixelated anode. Designed to handle photon rates up to 1 billion per second across a 7 cm active area, the detector achieves outstanding spatial and temporal resolutions of 5-10 m and below 50 ps r.m.s., respectively. The Timepix4 ASIC comprises approximately 230,000 pixels, each integrating analog and digital front-end electronics. This enables data-driven acquisition and supports data transmission rates up to 160 Gb/s. External FPGA-based electronics manage both configuration and readout. In order to test the timing performance of the Timepix4 ASIC we performed preliminary characterization of an assembly bonded to a 100 m thick n-on-p silicon sensor using a pulsed infrared laser, which demonstrated a per-pixel timing resolution of 110 ps, with cluster-based averaging methods improving to below 50 ps. Six prototype detectors incorporating different MCP stack configurations and end-spoiling depths were produced by Hamamatsu Photonics. We report on their characterization, including dark count rates, gain, and spatial and timing resolutions, assessed both in laboratory conditions and during a test-beam campaign at CERN's SPS facility.
Paper Structure (7 sections, 3 figures)

This paper contains 7 sections, 3 figures.

Table of Contents

  1. Introduction
  2. Hybrid detector structure and operating principle description
  3. Timepix4 characterization
  4. MCP-PMT characterization
  5. Dark Count Rate and Gain
  6. Timing Resolution
  7. Conclusions

Figures (3)

  • Figure 1: Simplified cross-section of the hybrid MCP-PMT assembly.
  • Figure 2: Cluster timing resolution as a function of the cluster charge, normalized by the cluster size. Different colors correspond to different cluster sizes. The timing resolution of the reference pixel has not been subtracted bib:Bolzonella_2024.
  • Figure 3: Estimated gain as a function of the MCP bias voltage, evaluated in the central region of the Timepix4 matrix.