Traceable Dosimetry for MeV Ion Beams

TL;DR

This paper introduces a new NIST-traceable ionization chamber for accurate dosimetry of low-energy MeV ion beams, aligning with international standards and improving measurement reliability for shallow penetration applications.

Contribution

It presents the implementation of a commercial, NIST-traceable ionization chamber for low-energy ion dosimetry, enhancing standardization and accuracy in shallow ion beam measurements.

Findings

Dose measurement is independent of ionization density in 10-150 keV/μm range.

The new method aligns with TRS-398 standards.

Improves dosimetry accuracy for shallow MeV ion beams.

Abstract

Standard dosimetry protocols exist for highly penetrating photon and particle beams used in the clinic and in research. However, these protocols cannot be directly applied to shallow penetration MeV-range ion beams. The Radiological Research Accelerator Facility has been using such beams for almost 50 years to irradiate cell monolayers, using self-developed dosimetry, based on tissue equivalent ionization chambers. To better align with the internationally accepted standards, we describe implementation of a commercial, NIST-traceable, air-filled ionization chamber for measurement of absorbed dose to water from low energy ions, using radiation quality correction factors calculated using TRS-398 recommendations. The reported dose does not depend on the ionization density in the range of 10-150 keV/micron.