portrait of an ultrastable x-ray generator O r , perhaps more properly: a graphic demonstration of the stability of our new ultrastable solid state DC x-ray generator. The graph shows the counts varying with changes in atmospheric conditions. Then, with the count corrected for these temperature and pressure variations, the exceptional stability of thisx-ray supply becomes evident. N.B.: the abscissa enccmpassesa t w o - d a y period. The need for an ultrastable x-ray source was an inevitable side effect of automation. Since automatic systems forsingle crystal diffractometry
are often programmed to run for days, instability of the x-ray source becomes intolerable. Obviously, to relate final intensity measurements to initial measurements in a meaningful w a y , one needs ample confidence in the stability of his x-ray generator. To this end, w e n o w offer an ultrastable solid state DC generator that serves to make automation in this field truly possible. Briefly, this is an x-ray generator and control with wide versatility. It can be used for single-tube operation or alternate two-tube operation, including three timers; single-tube operation
for fluorescence only systems; and simultaneous two-tube operation with six shutter timers. Incidentally, w e w o u l d be happy to send you a reprint of an interesting and pertinent paper entitled "The Measurement of X-ray Source Stability" thatwas presented to the American Crystallographic Association meeting at Bozeman in July of 1964. Requests for this will also provide us with an opportunity to send you a detailed description of this new ultrastable x-ray generator. Ask for file 6 2 3 8 A C I .
PICKER Picker Nuclear: 1275 Mamaroneck Avenue, White Plains, N.Y. 10605 nuclear See ACS Laboratory Guide for All Products/Sales Office Circle No. 149 on Readers' Service Card VOL. 39, NO. 1, JANUARY 1967
·
31 A
