Separation of weighable amounts of 10Be from proton irradiated graphite

Large amounts of (10B)e are produced at the PSI muon production facility by high-energy proton spallation in polycrystalline graphite. For the extraction of Be-10 out of large amounts of carbon, pyrolysis followed by chemical purification has been performed. Approx. 270 g of graphite from Target E92, which had received a total proton charge of 29 Ah between 2002 and 2005, have been burned at 1000 degrees C in a stream of oxygen. The volatile radioactive oxidation product (H2O)-H-3 was trapped in 3 water bubblers connected in series. The remainder, a white hygroscopic solid material mainly consisting of (Li2O)-Li-7, (BeO)-Be-9/10 and (B2O3)-B-10/11, was dissolved in HF and subsequently purified by ion exchange chromatography. Radioactive impurities such as Na-22, (44)Tt Mn-54 Co-69, (101) Rh, Ba-133 and Hf-172 have been separated from the final product. The purified material represents a mixture of approx. 6.5 mg Be-9 and 3.5 mg (3.3 MBq) Be-10. It is ready to be used for scientific investigations requiring large amounts of this precious isotope.