Pressure rise in medical cyclotron liquid targets: Transient analysis.

Transient behavior of proton-beam bombarded liquid-targets are studied at various initial conditions at the TR13 cyclotron at TRIUMF. Depending on the initial condition, experiments show a range of different responses from steady-state to self-sustained oscillations. To address this, a system of equations based on the conservation of mass and energy is proposed. Coupling between the beam and fluid-density and chemical reactions driven by the beam (radiolysis) are identified as the main reasons to describe this behavior. Excellent qualitative agreements are achieved.