Fig. 2From: ARAS: an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopesDiagram of the dual photodiode detection method. Photodiode 1 responds to both beta (β) and gamma (γ) particle radiation, while photodiode 2 responds only to γ radiation. The subtraction of the signals from the two photodiodes yields a measure of the local energy deposition from the beta particlesBack to article page