Novel Technique for Ultra-sensitive Determination of Trace Elements in Organic Scintillators

TL;DR

This paper introduces a neutron activation-based method for ultra-sensitive detection of trace elements in organic scintillators, achieving detection limits in the femtogram range, useful for neutrino experiments.

Contribution

The paper presents a novel neutron activation technique with preconcentration and separation steps for detecting trace elements in organic scintillators with unprecedented sensitivity.

Findings

Detection limits below 2.4x10^-15 g 40K/g LS

Detection limits below 5.5x10^-15 g Th/g LS

Detection limits below 8x10^-15 g U/g LS

Abstract

A technique based on neutron activation has been developed for an extremely high sensitivity analysis of trace elements in organic materials. Organic materials are sealed in plastic or high purity quartz and irradiated at the HFIR and MITR. The most volatile materials such as liquid scintillator (LS) are first preconcentrated by clean vacuum evaporation. Activities of interest are separated from side activities by acid digestion and ion exchange. The technique has been applied to study the liquid scintillator used in the KamLAND neutrino experiment. Detection limits of <2.4X10**-15 g 40K/g LS, <5.5X10**-15 g Th/g LS, and <8X10**-15 g U/g LS have been achieved.