The J-PET detector -- a tool for precision studies of ortho-positronium decays

TL;DR

The J-PET detector is a novel plastic scintillator-based system capable of precise measurements of ortho-positronium decays, enabling advanced studies of positronium properties and decay processes.

Contribution

This paper demonstrates the first successful measurements of ortho-positronium decays using the J-PET system, highlighting its capabilities beyond traditional crystal and semiconductor detectors.

Findings

First positronium production results obtained.

Lifetime distribution measurements performed.

Background sources analyzed and estimated.

Abstract

The J-PET tomograph is constructed from plastic scintillator strips arranged axially in concentric cylindrical layers. It enables investigations of positronium decays by measurement of the time, position, polarization and energy deposited by photons in the scintillators, in contrast to studies conducted so far with crystal and semiconductor based detection systems where the key selection of events is based on the measurement of the photons energies. In this article we show that the J-PET tomograph system is capable of exclusive measurements of the decays of ortho-positronium atoms. We present the first positronium production results, its lifetime distribution measurements and discuss estimation of the influence of various background sources. The tomograph s performance demonstrated here makes it suitable for precision studies of positronium decays including entanglement of the final state photons, positron annihilation lifetime spectroscopy plus molecular imaging diagnostics.