Simulation of the Avalanche Process in the G-APD and Circuitry Analysis of the SiPM

TL;DR

This paper models the avalanche process in G-APDs and analyzes SiPM circuitry, revealing that the known charge formula underestimates actual values and clarifying the role of the quenching resistor in the avalanche dynamics.

Contribution

It introduces a discrete model for Geiger-mode APD avalanche behavior and provides a more accurate analysis of SiPM circuitry, especially regarding the restoring time and resistor functions.

Findings

The known formula for avalanche charge underestimates actual charge.

The quenching resistor mainly restores the pixel rather than quenching.

The restoring time depends on pixel capacitance, quenching resistor, number of pixels, and load resistance.

Abstract

The discrete modeling of the Geiger-mode APD is considered. Results of modeling and experimental measurements with the SiPM show that the known formula for the charge of the avalanche pulse Q=dU*Cd underestimates its value. In addition, it is seen from the dynamic of the avalanche multiplication that the resistor Rq in photodiode, usually called a quenching resistor, in reality fulfills only the restoring function. The SiPM restoring time, taken into account the number of pixel N and the load resistance R, is T=Cd*(Rq+NR).