Design and Implementation of a Compact Analog Constant Fraction Discriminator for High-Resolution Timing in Gamma-Ray Spectroscopy

TL;DR

This paper introduces a compact, cost-effective analog CFD front-end for high-resolution timing in gamma-ray spectroscopy, utilizing a minimalist design without operational amplifiers for improved nuclear lifetime measurements.

Contribution

It presents a novel minimalist analog CFD design using discrete components, enhancing compactness and cost-effectiveness for gamma-ray detection applications.

Findings

Achieved precise timing with a small, integrated 16-channel CFD board.

Demonstrated cost savings through use of off-the-shelf components.

Validated performance for nuclear lifetime measurements.

Abstract

This work presents a custom analog front-end card designed for the read-out of PMTs coupled to lanthanum bromide scintillators. It integrates 16 discrete analog constant fraction discriminators (CFDs) on a compact 12x10 cm board, providing precise timing information for nuclear lifetime measurements. The design emphasizes cost-effectiveness, utilizing off-the-shelf discrete components, as well as compactness, achieved by using miniature coaxial connectors and cables as delay elements. The focus of this paper lies on the unusual and extremely minimalist analog shaper/discriminator design which is devised without operational amplifiers, making use of only a handful of RF transistors and LVDS receivers in place of comparators.