Simultaneous production of ²⁸Mg and ⁴⁷Ca by high-energy heavy-ion irradiation for applications in biology

Abstract

Mg-28 / Ca-47 / Multitracer / Ti target / V target / High-energy ion irradiation Summary. With the aim of preparing carrier-free 28 Mg and 47 Ca simultaneously, Ti, V and Fe targets were examined by irradiating with high-energy ions of 12 C, 14 N and 16 O accelerated by the RIKEN Ring Cyclotron. Among the targets, V gave the highest cross section for the formation of both 28 Mg and 47 Ca irrespective of the kind of beams. The cross section for the formation of 28 Mg by the reactions of Ti, V and Fe targets with ion beams increased in the order of 12 C< 16 O< 14 N. On the other hand, the three beams exhibited almost the same cross sections for the formation of 47 Ca by the reaction of a given target. Titanium and V were selected as prospective targets and 14 N as a suitable beam for the production of 28 Mg and 47 Ca. Chemical separation procedures of the radiotracers in carrier-and salt-free states have been established by using cation exchange resins. The recovery yields of 28 Mg and 47 Ca from Ti target were 70 and 90%, respectively, and the decontamination factor was less than 10 −5 . The recovery yields of 28 Mg and 47 Ca from V target were 80% and the decontamination factor was less than 10 −7 .

28 Radiochemistry

“…An examination of the 226 Ra : 228 Ra ratio from radium that is present in the baryte found in oil production sludge deposits can be used to determine its age. 320 The ratio of the cosmogenic nuclei 10 Be : 26 Al found in glacial deposits in northern India has been used to date 321 various stages in late quaternary glaciations to about 10-15 thousand years ago. And finally the abundance of 10 Be, 26 Al, 36 Cl and 54 Mn in galactic cosmic rays as measured 322 by a spacecraft spectrometer can be used to estimate a 'galactic confinement time' of about fifteen million years.…”

“…More usually, much lighter projectiles are used and specific product isotopes are sought. Thus both titanium and vanadium give good yields of 28 Mg and 47 Ca when bombarded 26 with nitrogen whilst alpha particles (50 MeV) react 27 with scandium to produce 48 V. If a scandium oxide target is irradiated a boron-11 beam 52 Mn is formed 28 and if the same ion-beam is used 29 with a cobalt target 66 Ga and 67 Ga result. The use of a carbon beam on the same cobalt target gives rise to 66 As and 67 As.…”