Measurement of the intensity ratio of Auger and conversion electrons for the electron capture decay of $^{125}$I

TL;DR

This study measures the ratio of Auger to conversion electrons in the decay of $^{125}$I, providing data crucial for targeted cancer therapy applications and comparing results with Monte Carlo simulations.

Contribution

It presents the first experimental measurement of the Auger to conversion electron ratio for $^{125}$I decay, highlighting discrepancies with existing theoretical models.

Findings

Measured Auger to conversion electron ratio for $^{125}$I decay.

Found that EADL-based calculations underestimate K Auger yields by 20%.

Provides data to improve atomic relaxation models for medical applications.

Abstract

Auger electrons emitted after nuclear decay have potential application in targeted cancer therapy. For this purpose it is important to know the Auger electron yield per nuclear decay. In this work we describe a measurement of the ratio of the number of conversion electrons (emitted as part of the nuclear decay process) to the number of Auger electrons (emitted as part of the atomic relaxation process after the nuclear decay) for the case of $^{125}$I. Results are compared with Monte-Carlo type simulations of the relaxation cascade using the BrIccEmis code. Our results indicate that for $^{125}$I the calculations based on rates from the Evaluated Atomic Data Library (EADL) underestimate the K Auger yields by 20\%.