Transit Time and Charge Correlations of Single Photoelectron Events in R7081 PMTs

TL;DR

This paper analyzes the transit time and charge response of R7081 photomultiplier tubes at single photoelectron levels, developing correlated probability models to improve Monte Carlo simulations for the Double Chooz experiment.

Contribution

It introduces a detailed analysis of SPE response in R7081 PMTs and creates correlated probability density functions for simulation purposes.

Findings

Measured combined transit time and charge response of PMTs

Developed charge-time correlated probability density functions

Enhanced Monte Carlo simulation accuracy

Abstract

During the calibration phase of the photomultiplier tubes (PMT) for the Double Chooz experiment the PMT response to light with single photoelectron (SPE) intensity was analysed. With our setup we were able to measure the combined transit time and charge response of the PMT and therefore we could deconstruct and analyse all physical effects having an influence on the PMT signal. Based on this analysis charge and time correlated probability density functions were developed to include the PMT response in a Monte Carlo simulation.