percent) square inches and gives 2.90 X 10° when multiplied
by the proper I/A from Fig. 9.
The latter intensity is from
2.5to 7.6 percent lower than the intensity determined from
the calibration of the standard, but agrees within the
experimental error.
The comparison of the Hg
203
~ ww Ste
similarly to the na? comparison,
photon intensities proceeds
The Hg 203 source strength
was given in actual disintegrations per second but only 78.7
of these disintegrations result in 279-kev gamma rays becauge
of the internal conversion in Hg 203 |
After the: appropriate
corrections are made the photon intensities obtained from
the extrapolated total absorption peak area and calibrated
source strength are 4.15 X 10° (+5 percent) and 4.22 X 106
(+5 percent) photons per second respectively.
The intensi-
ties obtained by the two methods differ by less than 2 percent.
well
within experimental error.
With 54 recordings of the 145 pc Hg@°3 standard and 94
recordings of the 75.6 uc na’? standard made over a period
of several months already available, it was decided to make
@ least squares fit of the decay curve to get a quantitative
idea of the machine's stability.
It was assumed that the
functional form of the equations relating area to time was
A = exp(-At) or a polynomial of the form y = a + a,t (a
straight. line) where y = InA,.
31
i.
~