ORNL-1816 - the Molten Salt Energy Technologies Web Site
ORNL-1816 - the Molten Salt Energy Technologies Web Site
ORNL-1816 - the Molten Salt Energy Technologies Web Site
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a $ 020<br />
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a<br />
E O<br />
UNCLASSIFIED<br />
2-01-059-!5<br />
0 1 2 3 4 5 6 7 8 9<br />
THICKNESS (in )<br />
Fig. 12.4. Radiation Heating of a 9din.-Thick<br />
Beryllium Slab by Normally Incident Photons.<br />
In Fig. 12.4 <strong>the</strong> smooth fits to <strong>the</strong> statistical<br />
data are presented for normally incident photons of<br />
energy 0.5, 1.5, and 5.0 mOc2, The effect of <strong>the</strong><br />
reflected photons on <strong>the</strong> energy absorption curve<br />
is readily seen at <strong>the</strong> entrance face of <strong>the</strong> slab.<br />
The value of <strong>the</strong> fraction of energy absorbed per<br />
inch at <strong>the</strong> entrance face for <strong>the</strong> incident photons<br />
can be calculated by multiplying ps, <strong>the</strong> scattering<br />
cross section, by f, <strong>the</strong> average fraction of energy<br />
absorbed by <strong>the</strong> ~naterial.~ These values for 0.5,<br />
1.5, and 5.0 mOc2 are, respectively, 0.118, 0.123,<br />
and 0.089. The large contribution of <strong>the</strong> reflected<br />
component is especially evident for <strong>the</strong> 0.5-m0c2<br />
Dhotons at <strong>the</strong> entrance face as <strong>the</strong> difference be-<br />
tween 0.1 18<br />
12.4. The e<br />
1.5-mnc2 ph<br />
5 060<br />
Z 056<br />
052<br />
8 048<br />
044<br />
8 040<br />
036<br />
032<br />
5 028<br />
5 024<br />
g 020<br />
PERIOD ENDING DECEMBER 10,7954<br />
UNC-ASSI~IEO<br />
2-01-059-14<br />
Z 016<br />
8 012<br />
6 008<br />
k 004<br />
$ 0<br />
0 1 2 3 4 5 6 7 8 9<br />
THICKNESS (in )<br />
Fig. 12.5. Radiation Heating of a 9-ireThick<br />
Beryl lium Slab by Slant-inci dent 1.5.m oc2 F'hoton s.<br />
induced injury with time. Just recently <strong>the</strong> ANP<br />
Medical Advisory Group (ANP-MAG) issued recom-<br />
mendations' which made some concessions in this<br />
direction in that increased total doses were allowed<br />
for schedules which distributed <strong>the</strong> radiatilon over<br />
longer times. It has been demonstrated9 that <strong>the</strong><br />
ANP-MAG recommendations can be expressed to<br />
within 4% by a ma<strong>the</strong>matical formulation with three<br />
parameters based on a model of partly irreparable<br />
injury and partly injury which recovers exponen-<br />
tially with time, The model was previou:jly sug-<br />
gested by Blair.10'12 The ma<strong>the</strong>matical formula-<br />
tion is much more flexible than <strong>the</strong> Biological<br />
Planning Chart which expresses <strong>the</strong> ANP-MAG<br />
recommendations, since it gives a unique value of<br />
'"Yjnutes of <strong>the</strong> 3rd ANP-MAG Meetin - 11-12 May<br />
1954, School of Aviation Medicine, 5-18,862.<br />
Several Weeks, UR-312 (Feb. 10, 1954).<br />
145