Comparing Efficiencies of isotope 48Calcium Reduction and Recovery Methods

The neutron abundant 48Ca isotope has a very low natural occurrence (0.187%). Highly enriched

starting material for the production of nuclei in particle accelerators including the Argonne

Tandem Linac Accelerator System (ATLAS) is exceptionally valued. We aim to recover

enriched 48Ca metal from a mixed CaCO3+Zr sample with unknown quantity of 48Ca. The goal

is to carry out two chemical reactions within a standard ECR ion source resistively heated oven.

A sample of natural CaC03+Zr with a ratio 1:2 of Ca:Zr by mass was prepared. An oven

temperature calibration with power input set values was performed prior to baking the sample,

expelling CO2 in a gaseous state and yielding CaO which is then reduced at a slightly higher

temperature via reduction with Zr metal to form Ca metal and ZrO2. The Ca metal is evaporated

to a small area of a pre-weighed tantalum deposition plate while the ZrO2 remains in the oven

crucible. The process was repeated using a resistively heated vapor deposition system to record

and compare both Ca metal production efficiencies with a goal of finding a process for use with

the enriched 48Ca material. In the vapor deposition system, a CaCO3 and Zr mixture with the

same ratio is pressed and placed in a tantalum pinhole boat, which creates a directional vapor of

Ca metal under high temperature. The Ca is deposited onto a pre-weighed glass substrate and

reweighed after deposition to determine the Ca mass. Calcium metal recovery efficiencies will be

reported.