to the reduction of oh content in the melt consequently although one succeeded in growing a single crystal ingot the crystal and or crucible cracked during cooldown the situation was different in the case of kcl and nacl grown by the vertical bridgman method in quartz crucibles with ccl 4 as the rap source the single crystal ingot slipped out easily and the crucibles were reusable over and over this feature was reproduced in the growth of 3 to 10 cm diameter ingots a comparison of the steady state effluent kcl rap growth versus pyrolysis of ccl 4 was made growth at 800 u00b0 c and v 0 5 cm 3 sec gave 15 millimoles cl 2 per hour pyrolysis at 800 u00b0 c and a flow v of 0 8 cm 3 sec gave 12 millimoles cl 2 per hour noteworthy changes have resulted in the performance parameters of these anion ultrapure materials in kcl comparing the rap crystal with earlier vintage materials f horrigan c klein r rudko and d wilson microwaves pp 68 76 january 1969 the measured absorption in a 10 6 u03bcm co 2 laser colonimeter yielded an absorption coefficient of 0 00013 cm 1 which value is more than.