A 24-Channel Ultra-Low-Noise Preamplifier for dN/dx Measurements with Drift Tube Detectors

TL;DR

This paper introduces a 24-channel ultra-low-noise preamplifier for drift tube detectors, enabling precise dN/dx measurements crucial for particle identification in collider experiments.

Contribution

The paper presents a novel three-stage SiGe transistor-based preamplifier with exceptional noise performance and validation in CERN test beam experiments.

Findings

Achieved a charge gain of 21.11 mV/fC and bandwidth of 542 MHz.

Measured voltage noise density of 0.35 nV/√Hz, surpassing state-of-the-art preamplifiers.

Validated performance with a high signal-to-noise ratio of 73 in CERN tests.

Abstract

Cluster counting dN/dx is a promising method to enhance particle identification for gaseous detectors, especially in next-generation collider experiments like the FCC-ee, where good pion-kaon separation over a broad momentum range is essential. However, its implementation in large-scale systems has been limited by the challenging requirements for high-resolution signal amplification and readout. This paper presents a 24-channel ultra-low-noise preamplifier board designed for drift tube detectors to enable dN/dx measurements. The three-stage amplification topology employs SiGe transistors and integrates dedicated noise-minimization techniques, achieving a charge gain of 21.11 mV/fC from 0.3 fC to 50 fC, a bandwidth of 542 MHz, and a voltage gain of 47.8 dB. The measured voltage noise density is 0.35 nV/sqrt(Hz), surpassing most of the state-of-the-art preamplifiers for gaseous and silicon detectors. Validation tests conducted on the sMDT chambers at the CERN Proton Synchrotron test beam facility demonstrate that the proposed design meets the stringent preamplifier requirements for implementing the dN/dx method in drift-tube detector systems, achieving an equivalent noise charge of 0.14 fC and a signal-to-noise ratio of 73 when operated with a He:iC4H10 (90:10) gas mixture. The design also shows promise for broader application in other gaseous or semiconductor detectors.