  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.
