Patent Number: 
Section: claims

1. A method for generating 225Ac, the method comprising:a) supplying a converter in thermal communication with a heat sink material wherein the heat sink material defines channels adapted to receive a coolant fluid such that no coolant fluid contacts the converter;b) contacting a primary electron beam with the converter for a time sufficient to produce a secondary beam of gamma particles; andc) contacting the beam of gamma particles to a target containing about 100 mg of 226Ra target material to produce more than 1 Ci of the 225Ac within 5 days of irradiation, wherein a cross section of the beam of gamma particles is similar to a cross section of the target. 2. The method as recited in claim 1 wherein the primary electron beam is comprised of electrons with an energy between 30 MeV and 45 MeV with total beam power between 10 to 20 kW. 3. The method as recited in claim 1 wherein the coolant fluid maintains the converter at temperatures less than 1000° C. while the temperature of the coolant fluid exiting the heat sink is less than 100° C. 4. The method as recited in claim 1 wherein the 225Ac is free of contaminants. 5. The method as recited in claim 1 wherein the target is contacted with additional heat sink material similar to the aforementioned heat sink material and the additional heat sink material is positioned downstream from the aforementioned heat sink material.