and 1x10'* fast neutrons per square

centim
23 for the va

Fr? GQ

contrioution at specific slant ran
actual thermal- and fast-neutron f

x

actually absorbed by the soil, ani the build-up
into account. Details are given in the Appendi

2.6

COMPARISON OF LASL AND ESL FILM DATA

(U) A comparison of the LASL film data with the
tory (ESL) film data shows that the LASL data are
the ESL data. An investigation into the cause of
carried out by LASL during Operation Teapot and rec:

Bemis (Reference 18), who recommended that all the

d

D
to

e

by 13 percent because of calibration difficulties.
In comcarison vith
energy-independent ion chambers, the individual emulsion results cotaines
by use of the LASL holder were high by factors varying from 10 to 20
percent, and the individual emulsion results obtained by use of tne NBS
holder were low by factors varying from 7 to 19 percent.
The 12-rercsent
calibration factor is used in this report to correzz the LASL fiim dat
Describing the LASL film data in this report as uncorrected, meanc tna
the data have not been corrected for neutron effects but have deen cor
ted for calibration error.
The individual emulsion corrections are not
applied in this report, since they are applicable only at distances of 1700

to 3300 yards, and to the type of shots for which they were measured.

The

individual emulsion variation is assumed to be due to the energy de venience
of the emulsion:
the emulsions in the LASL holder are more sensit
Since the gamma spectrum is softer at distances clceser to groun
the correction factors should be different.
Currently the averas
the LASL and ESL gamma data appears to present a good estimate of the
gama dose.

(U) An example of the calculations used to obtain the correctio:

factors is presented in the Appendix.
Formulae for correcting the
to other air densities are also presented in the Appendix.

(U) All shot information was obtained from References 19 ard 20.

27

mM

3

ot
oO

«at

Unless otherwise specified, the meteorological data were obtained at
level.
The meteorological data tables include slan -range-corre 7 vion
factors and dose-correction factors as well as
m ratur®, pressure, ant
density values.

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