Fusion Science and Technology / Volume 41 / Number 3P2 / May 2002 / Pages 716-720
Decontamination and Waste / Proceedings of the Sixth International Conference on Tritium Science and Technology Tsukuba, Japan November 12-16, 2001
A novel laser heating technique has recently been applied to removing tritium from carbon tiles that had been exposed to deuterium-tritium plasmas in the Tokamak Fusion Test Reactor (TFTR). A continuous wave neodymium laser, of power up to 300 watts, was used to heat the surface of the tiles. The beam was focussed to an intensity, typically 8 kW/cm2, and rapidly scanned over the tile surface by galvanometer driven scanning mirrors. Under the laser irradiation, the surface temperature increased dramatically, and temperatures up to 2,300 °C were recorded by an optical pyrometer. Tritium was released and circulated in a closed loop system to an ionization chamber that measured the tritium concentration. Most of the tritium (up to 84%) could be released by the laser scan. This technique appears promising for tritium removal in a next step DT device as it avoids oxidation, the associated deconditioning of the plasma facing surfaces, and the expense of processing large quantities of tritium oxide. Some engineering aspects of the implementation of this method in a next step fusion device will be discussed.