(Les ible of),
Lets
t, © 3 hours (time particle is deposited on skin)
ty © 27 hours (tire particle {s removed)
Assumes
200jreps = total dose required in one day to produce recognissble erythema
O.1 cam @ radius of imaginary sphere within which cells mist receive
2000 reps or larger.
According to Appendix E, 2.5 x 10°7 repo/disintegration is delivered
to surface of imaginary sphere 0.1 centineter in radius
259 x 22°
‘
2 8 x 109 disintegrationg required
Cw AgelEee - 40.7
Bx 10? 25451.20.2770.
A, 21.55 x 109 d/nr og about
12.0pe at Bf 3 hours
Of course, the radius of the imaginary sphere selected vill materially |
affect the calculations,
Por example, a radius of 0.3 om would require a
particle of about 120 microcuries at 43 hours to give the same dose,
e (AY
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on the Kin.
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