Production of isotopes using high power proton beams
The invention provides for a method for producing isotopes using a beam of particles from an accelerator, whereby the beam is maintained at between about 70 to 2000 MeV; and contacting a thorium-containing target with the particles. The medically important isotope 225 Ac is produced via the nuclear reaction (p,2p6n), whereby an energetic proton causes the ejection of 2 protons and 6 neutrons from a 232 Th target nucleus. Another medically important isotope 213 Bi is then available as a decay product. The production of highly purified 211 At is also provided.
1. A method for producing astatine isotope, the method comprising:
a. irradiating a target containing 232 Th with a 500 kW, 200 MeV proton beam to produce 215 Ra, wherein the 215 Ra decays into 211 Rn;
b. extracting the 211 Rn from the target;
c. collecting the extraction 211 Rn; and
d. generating about 8 Ci of 211 At from the collected 211 Rn per day of irradiation.
2. The method as recited in claim 1 wherein the 211 Rn is continuously extracted from the target.
3. The method of claim 1 wherein the target containing 232 Th comprises a porous thorium target.
4. The method of claim 3 wherein the porous thorium target comprises thorium foam defining about 50 percent interconnected pores.
5. The method of claim 1 wherein the target containing 232 Th incorporates thorium as a thorium material selected from the group consisting of ThC, a thorium metal, ThO, a thorium alloy, a thorium composite, or combinations thereof.
6. The method of claim 1 wherein the target comprises a plurality of thin plates.
7. A method for producing 211 Rn, the method comprising:
a) irradiating a target containing 232 Th with a beam of protons maintained at an energy of about 100 to 400 MeV to produce 215 Ra; and
b) generating about 4.5 Ci of 211 Rn in 24 hours of irradiation by allowing the 215 Ra to decay into 211 Rn.
8. The method of claim 7 wherein the target containing 232 Th comprises a porous thorium target.
9. The method of claim 8 wherein the porous thorium target comprises thorium foam defining about 50 percent interconnected pores.
10. The method of claim 7 wherein the target containing 232 Th incorporates thorium as a thorium material selected from the group consisting of ThC, a thorium metal, ThO, a thorium alloy, a thorium composite, or combinations thereof.
11. The method of claim 7 wherein the target comprises a plurality of thin plates.