Thermal desorption of silicon from polycrystalline tungsten surfaces

The adsorption of Si on polycrystalline tungsten surfaces was studied for the first time by means of thermal desorption. Instead of the main peak of Si ($\text{m}\text{e}\text{=28}$), the isotope ($\text{m}\text{e}\text{=30}$) contained naturally (～3%) was monitored by mass spectrometry. This method can reduce the contribution from CO to the mass signal of Si. Two desorption peaks were observed at 1480 and 1820 K. The activation energies for the desorption were estimated to be about 90 and 110 kcal/mol, respectively.