Patent ID: 8249211

Claim:
A method of preparing a radioisotope product comprising: introducing a target fluid into a target cavity defined by an inner sleeve arranged within an outer envelope, the inner sleeve and outer envelope defining a return space therebetween, the outer envelope having an elongated body and holding a total volume of the target fluid, the target fluid being present in the target cavity and return space; irradiating the target fluid within the target cavity with an energetic particle beam to form the radioisotope product, the particle beam having a beam path extending through the inner sleeve from a first end of the elongated body of the outer envelope to a second end of the elongated body of the outer envelope; and inducing movement within the target fluid as it is being irradiated such that the target fluid in the inner sleeve flows countercurrent to the particle beam in the inner sleeve during irradiation from the second end of the outer envelope to the first end of the outer envelope while the target fluid in the return space flows from the first end of the outer envelope to the second end of the outer envelope, wherein the target fluid is recirculated within the inner sleeve and the outer envelope during irradiation without the target fluid exiting the outer envelope.