A Thermal Sublimation Generator of $^{131 \textrm{m}}$Xe

Stable and unstable isotopes of the heavy noble gas xenon find use in various medical applications. However, apart from $^{133}$Xe, used for Single Photon Emission Computed Tomography, radioactive isotopes of xenon are currently complicated to obtain in small quantities. With the GAMMA-MRI project in mind, we investigated a thermal sublimation generator of the long-lived excited state (isomer) $^{131 \textrm{m}}$Xe. This production method utilized the decay of $^{131}$I, obtained commercially from a hospital supplier in the form of Na131I powder. Heat treatments of the Na $^{131}$I powder and cryogenic trapping of released $^{131 \textrm{m}}$Xe allowed us to collect up to 88% of the produced xenon. Our method provides an isomeric mixture of $^{131 \textrm{m}}$Xe and $^{131}$Xe. With improvements in scalability and chemical purification, this method could be a cost-effective source of $^{131 \textrm{m}}$Xe for small-scale experiments.