An apparatus for producing a radionuclide includes a target chamber, a particle beam source operatively aligned with the target chamber, and a regenerative turbine pump for circulating a target fluid through the target chamber via first and second liquid transports. During bombardment of the target liquid in the target chamber by the particle beam source, the target liquid is prevented from reaching vaporization due to the elevated pressure within the target chamber and/or the rapid flow rate through the target chamber. A cooling system can be provided to circulate coolant to the first and second liquid transport conduits, the target chamber and the pump to ensure that the target liquid is cooled upon recirculation back into the target chamber.