The Flash ADC system and PMT waveform reconstruction for the Daya Bay Experiment

TL;DR

This paper details the design and validation of a Flash ADC system and a novel waveform reconstruction method for the Daya Bay experiment, achieving high linearity and consistency in PMT signal analysis.

Contribution

It introduces a new deconvolution-based waveform reconstruction method that significantly improves linearity in liquid scintillator calorimetry.

Findings

Achieved 1% residual non-linearity in waveform reconstruction.

Validated method with data and Monte Carlo simulations showing 1% consistency.

Demonstrated the system's effectiveness for energy response analysis.

Abstract

To better understand the energy response of the Antineutrino Detector (AD), the Daya Bay Reactor Neutrino Experiment installed a full Flash ADC readout system on one AD that allowed for simultaneous data taking with the current readout system. This paper presents the design, data acquisition, and simulation of the Flash ADC system, and focuses on the PMT waveform reconstruction algorithms. For liquid scintillator calorimetry, the most critical requirement to waveform reconstruction is linearity. Several common reconstruction methods were tested but the linearity performance was not satisfactory. A new method based on the deconvolution technique was developed with 1% residual non-linearity, which fulfills the requirement. The performance was validated with both data and Monte Carlo (MC) simulations, and 1% consistency between them has been achieved.