An apparatus used to make 22Na sources for use in low-energy positron beams

Abstract

The 22Na nuclide, having a relatively long half-life (2.6 year) and high branching ratio for positron emission (90%), is often the preferred nuclide for producing low-energy positron beams. Suitable commercial 22Na sources are, however, relatively expensive and are sometimes subject to delay in supply. To circumvent such problems in the long-term maintenance of our positron beam a radioactive source deposition apparatus, capable of preparing up to 20 mCi 22Na sources from aqueous solution, has been designed and constructed. The 22NaCl solution is deposited onto a platinum substrate, dried and remotely capped with 3 μm of titanium. The apparatus has been safely employed to produce both 10 mCi and 20 mCi 22Na sources both of which are now in use in our magnetically guided positron beam.

The 22Na nuclide, having a relatively long half-life (2.6 year) and high branching ratio for positron emission (90%), is often the preferred nuclide for producing low-energy positron beams. Suitable commercial 22Na sources are, however, relatively expensive and are sometimes subject to delay in supply. To circumvent such problems in the long-term maintenance of our positron beam a radioactive source deposition apparatus, capable of preparing up to 20 mCi 22Na sources from aqueous solution, has been designed and constructed. The 22NaCl solution is deposited onto a platinum substrate, dried and remotely capped with 3 μm of titanium. The apparatus has been safely employed to produce both 10 mCi and 20 mCi 22Na sources both of which are now in use in our magnetically guided positron beam.