Prototype of Readout Electronics for the ED in LHAASO KM2A

TL;DR

This paper presents a prototype readout electronics system for the EDs in the KM2A detector array of LHAASO, enabling accurate charge and timing measurements over a large dynamic range in a challenging environment.

Contribution

The paper introduces a novel trigger-less readout electronics architecture with simplified data transmission for large-scale air shower detectors.

Findings

Achieved accurate charge and timing measurements over a wide amplitude range.

Successfully implemented trigger-less digitization close to PMTs.

Met all project requirements in experimental tests.

Abstract

The KM2A(one kilometer square extensive air shower array) is the largest detector array in the LHAA- SO(Large High Altitude Air Shower Observatory) project. The KM2A consists of 5635 EDs(Electromagnetic particle Detectors) and 1221 MDs(Muon Detectors). The EDs are distributed and exposed in the wild. Two channels, Anode and Dynode, are employed for the PMT(photomultiplier tube) signal readout. The readout electronics proposed in this paper aims at the accurate charge and arrival time measurement of the PMT signals, which cover a large amplitude range from 20P.E(photoelectrons) to 2x10^5 P.E. By using the Trigger-less architecture, we digitize signals close to the PMTs. All digitized data is transmitted to DAQ(Data Acquisition) via the simplified WR(White Rabbit) protocol. Compared with traditional high energy experiments, high-precision of time measurement in such a large area and suppression of temperature effects in the wild become the key techniques. Experiments show that the design has fulfilled the requirements in this project.