a

1/2 inch

Zz

5

inches

ro = 3/8 tnch

b= (6 - 2/1) inches
where 1/u is the mean-free-path of gamma radiation

in lead.
K was evaluated by means of numerical integration for values of E

(and corresponding values of

b) at 200-kev intervals between O and 2 Mev and at

|

3 Mev (Fig. 8).

The absolute photon intensity is a combination of these
various correction factors,

i.e.:

I = AC/vwk
A graph of I/A versus E is snown in Fig. 9.

After reading

the energetically appropriate I/A from the graph, the number
was multiplied by the area of the total absorption peak of

the corresponding famma ray to obtain absolute photon intensity of that line.
RESULTS
The absolute photon intensities with their estimated
errors are listed for each gamma line of each record in

Tables

2 and

3.

The abbreviated sample notation used for

19

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