Modeling the pressure rise of a liquid target on a medical cyclotron: Steady-state analysis

The steady-state behaviour of a liquid target used to produce medical isotopes by low-energy cyclotrons is studied. A model based on the conservation of mass and energy is proposed to describe the pressure rise of the target assuming equilibrium between liquid and vapour phases during irradiation. The effects of water radiolysis are taken into account. Excellent agreement is achieved between the model, and both constant-temperature bath tests and experiments conducted on a 13 MeV cyclotron at TRIUMF.