Deuterium retention in liquid tin exposed to atomic deuterium flux

Liquid tin samples at a temperature of 250 degrees C were exposed to neutral deuterium atoms at a flux of about 10(24) m(-2) s(-1). The source of deuterium (D) atoms was the flowing afterglow of a low-pressure deuterium plasma sustained with a microwave discharge in the surfatron mode. The samples were analyzed by thermal desorption spectroscopy and time of flight secondary-ion mass spectrometry. An immeasurably low concentration of deuterium was detected in the pure tin. However, within the native layer of tin oxide, up to 165 ppm D/Sn was absorbed while the sample was exposed to D atoms. The deuterium concentration in the solid samples peaked at the D fluence of about 5 x 10(25) m(-2). At the fluence of several 10(26) m(-2) the concentration dropped below the detection limit, which was about 50 ppb D/Sn. The results were explained by the reduction of the oxide film under exposure to D atoms at large fluences. Thus, the retention of hydrogen isotopes in the liquid tin divertor of a fusion reactor is unlikely since the effect of the plasma makes it possible to reduce the tin oxide layer.

Automated summary

The research revealed that only a small amount of deuterium was present in liquid tin, but a higher concentration of deuterium was absorbed in the native layer of tin oxide.