Improved method for measuring low concentration radium and its application to the Super-Kamiokande Gadolinium project

TL;DR

This paper presents an improved chemical extraction method for measuring low concentrations of radium, achieving higher speed and recovery rates, and demonstrates its application in the Super-Kamiokande Gadolinium project.

Contribution

Developed a faster, more efficient radium extraction method with higher recovery rates, enabling sensitive measurements for neutrino detector applications.

Findings

Extraction speed increased threefold

Radium recovery rate improved to >99.9%

Achieved sensitivity at 10^{-1} mBq level

Abstract

Chemical extraction using a molecular recognition resin named "Empore Radium Rad Disk" was developed to improve sensitivity for the low concentration of radium (Ra). Compared with the previous method, the extraction process speed was improved by a factor of three and the recovery rate for $^{226}$Ra was also improved from 81$\pm$4% to $>$99.9%. The sensitivity on the 10$^{-1}$ mBq level was achieved using a high purity germanium detector. This improved method was applied to determine $^{226}$Ra in Gd$_2$(SO$_4$)$_3{\cdot}$8H$_2$O which will be used in the Super-Kamiokande Gadolinium project. The improvement and measurement results are reported in this paper.