Isotope Production and Applications
The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800 MeV proton beam from the Los Alamos Meson Physics Facility (LAMPF). Those target irradiations continued through the 1990s at LAMPF and its successor organization, the Los Alamos Neutron Science Center (LANSCE). The Los Alamos program has supplied a wide range of radioisotopes to medical researchers and other scientists all over the world. Throughout its history, the Los Alamos program has been a leader in developing and producing new and unique isotopes for research and development. Some of the isotopes, such as aluminum-26 and silicon-32, are unique to Los Alamos; they are produced nowhere else in the world. For others, such as germanium-68 and strontium-82, the Los Alamos program has been and continues to be a major supplier. The changing mission for the accelerator facility in the early 1990s provided an opportunity to upgrade and improve the irradiation capabilities of the Los Alamos radioisotope program. This resulted in the Isotope Production Facility (IPF) construction project, which focused on building a new target area dedicated to isotope production and research. The new facility utilizes a 100 MeV proton beam extracted from the main LANSCE accelerator and directed to a modern target irradiation facility.
The LANSCE 100 MeV Isotope Production Facility
In the fall of 2004, construction was completed on a new beam line and target area at the Los Alamos Neutron Science Center (LANSCE). The new beam line diverges from the main LANSCE accelerator at the transition region between the 100 MeV drift tube linac and the 800 MeV side coupled linac. The linac accelerates both positively charged (H+) and negatively charged (H-) beams simultaneously. A pulsed (kicker) magnet was installed in the transition region so that a portion of the H+ beam can be deflected into the new beam line without impacting H- beam operations. This allows a high intensity (up to 250 microampere) proton beam with a nominal energy of 100 MeV to be delivered to the target station for radioisotope production.
The facility consists of two levels. The lower level is underground and houses the beam line and target systems. The upper level includes an equipment room and a hot cell. Targets are loaded and retrieved through the hot cell using special remote handling equipment. This makes it possible to insert and remove targets without entering the beam tunnel or otherwise impacting accelerator operations. The target station allows for irradiation of several targets simultaneously, each at its own energy range. This facility allows production of a wide range of radioisotopes to support medical diagnosis and treatment and scientific research.
The TA-48 Hot Cells Facility
The TA-48 hot cells consist of a connected bank of thirteen hot cells with a specialized function for each cell. The cells are each configured with 20 inches of ferro–phosphorous concrete to provide adequate shielding from the irradiated IPF targets and subsequent isotope products. The hot cell windows consist of three panes of successively thicker-leaded-glass, with specialized oil separating each window that is optically matched to the glass permitting a clear, undistorted view of the hot cell interior. Cells are connected to one another by a train that can be used to transport targets, chemicals, and equipment needed for a given operation. The facility is operated under cGMP (current Good Manufacturing Practices) and under the oversight of the US Food and Drug Administration, given that some of the materials produced there are deemed as pharmaceutical ingredients for end use in humans.
Irradiated targets are introduced into the hot cell bank under heavy shielding. Once they are unpackaged and transferred to the desired cell for chemistry, the target casing can be punched or cut to provide access to the target material inside. Target dissolution can then be performed, which usually involves an aqueous acidic solution, depending on the target material. In the case of rubidium metal targets, a hot cell must be purged with argon prior to sequential dissolution of the target material in isopropanol and water to control reactivity during this process. A variety of conventional wet-chemistry techniques are then performed in the hot cell–a set of tasks requiring operators to take years of training in the art of remote manipulation–to isolate the isotope of interest.
Final products undergo rigorous radioassay and analysis for stable isotopes to ensure that the product is free of impurities that may preclude the intended end use. Products are typically packaged in DOT Type A containers that can be shipped around the country and the world. The program has historically made approximately 230 shipments each year to domestic and foreign end users.
Strontium-82 is supplied to our customers for use in Sr-82/Rb-82 generator technologies. The generators in turn are supplied to hospitals and medical laboratories to support cardiac imaging through Positron Emission Tomography (PET). The generator technology was developed by the DOE Medical Radioisotope Program during the 1970s and 1980s, and the technology was transferred to private industry in the late 1980s. The DOE continues to be one of the principle suppliers of the strontium–82 for the generators. Strontium-82 is produced by bombarding rubidium chloride or rubidium metal with protons utilizing the energy range between 40 and 90 MeV.
Germanium-68 is used for calibration sources for medical imaging equipment. Hospitals and research institutions across the nation use such sources every day to calibrate PET scanners. Without such calibrations the usefulness of equipment for medical imaging and research would be severely limited. Germanium-68 is produced by bombarding gallium metal with protons utilizing the energy range between 15 and 65 MeV. In addition to source technologies, Ga-68 (the daughter isotope of Ge–68) is emerging as a promising PET imaging isotope. Silicon-32 is used in oceanographic research to study the silicon cycle in marine organisms, principally diatoms. Its use in this application has dramatically improved the timeliness and quality of data available in this area of environmental research. Silicon-32 is produced by high-energy (> 90 MeV) proton bombardment of potassium chloride.
Other isotopes that have recently shipped from LANL's isotope program include cadmium-109 (x-ray fluorescence sources), arsenic-72 (medical research), and sodium-22 (PET sources).
In addition to our routine isotope products, the LANL Isotope Program is focused on developing the next suite of isotopes and services to meet the Nation's emerging needs. The LANL Isotope Program's R&D strategy is focused on four main areas:
Medical Applications are a key focus for research including the development of new isotopes for medical imaging and therapy. Recent efforts include investigations into cross section measurements for production of actinium-225 to validate new production methods, accelerator-based production of high specific activity rhenium-186, and production of selenium-72 as the parent isotope in a novel Se-72/As-72 generator (see links for articles in these areas).
Fundamental Nuclear Physics Studies are centered on isotopes for unique cross section measurements to support astrophysics and fundamental nuclear physics studies. Additional focus is provided to measurement of production cross sections for a variety of previously uncharacterized isotopes in energy region of 40-800 MeV (H+).
Process Development Improvement focuses on the development of cutting edge targetry (modeling, design, and fabrication) as well as the development of new chemical process technologies.
Proton Beam Simulation with MCNPX: Germanium Metal Activation Estimates Below 30 MeV Relevant to the Bulk Production M. Fassbender, W. Taylor, D. Vieira, M. Nortier, H. Bach, K. John Applied Radiation and Isotopes, 2012, 70, 72-75
Selenium-72 Formation via natBr(p,x) Induced by 100 MeV Protons: Steps Towards a Novel 72Se/72As Generator System B. Ballard, D. Wycoff, E.R. Birnbaum, K.D. John, W.A. Taylor, F.M. Nortier, J.W. Lenz, S.S. Jurisson, C.S. Cutler, M.E. Fassbender Applied Radiation and Isotopes, 2012, 70, 595-601
225Ac and 223Ra Production Via 800 MeV Proton Irradiation of Natural Thorium Targets J.W. Weidner, S.G. Mashnik, K.D. John, B. Ballard, E.R. Birnbaum, L.J. Bitteker, A. Couture, M.E. Fassbender, G.S. Goff, R. Gritzo, F. Hemez, J.L. Ullmann, L.E. Wolfsberg, and F.M. Nortier Applied Radiation and Isotopes, 2012, 70, 2590-2595
Radioarsenic from a Portable Se-72/As-72 Generator: A Current Perspective B. Ballard, E.R. Birnbaum, K.D. John, F.M. Nortier, D. R. Phillips, M.E. Fassbender Current Radiopharmaceuticals, 2012, 5, 264-270.
Proton-induced Cross Sections Relevant to Production of 225Ac and 223Ra in Natural Thorium Targets Below 200 MeV J.W. Weidner, S.G. Mashnik, K.D. John, F. Hemez, B. Ballard, H. Bach, E.R. Birnbaum, L.J. Bitteker, A. Couture, D. Dry, M.E. Fassbender, M.S. Gulley, K.R. Jackman, J.L. Ullmann, L.E. Wolfsberg, and F.M. Nortier Applied Radiation and Isotopes, 2012, 70, 2602-2607
Cross Sections from 800 MeV Proton Irradiation of Terbium J.W. Engle, S. Mashnik, H. Bach, A. Couture, R. Gritzo, D. M. Smith, L.J. Bitteker, J.L. Ullman, M. Gulley, C. Pillai, K.D. John, E.R. Birnbaum, F.M. Nortier Nucl. Phys. A, 2012, 893, 87-100
Price Quotes and Isotope Ordering
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Los Alamos Isotope Availability
Information about isotope availability and scheduling as well as requests concerning unlisted radioisotopes may be obtained from:
Information regarding technical details on listed and unlisted isotopes may be obtained from: