Vapour pressure control of iodide decomposition cell - for metal purificn., by direct vapour pressure measurement

摘要

The vapour pressure in an iodide decompsn. cell is controlled by direct measurement of the vapour pressure in the cell and use of this measurement to control the vapour pressure, e.g. by controlling the temp. of the cell lid or the amt. of iodine in the cell. The method is used to control cells for purificn. of metals such as zirconium and hafnium. Direct measurement of the vapour pressure gives more accurate control to improve iodide crystal growth and yield.