remain on ilmer, with the large one being stored in the Rad-Safe arce.
Sinee all stations are on land masses, access for installation prior
to Brevo may be by boat. Recovery of records and reactivation of
Stations will require helicopter flights. No courier or sample return
flights are required.
3.3
idject Number:
}
2.3
AFSWP
Pro jeg
pificer:
Title:
Neutron Flux and Spectrum
Measurements
Performing Agency:
Mr. T. D. Hanscome
Naval Research
Laboratory
3.3.1 Objective ~
To document the fast neutron and thermal neutron flux as a
function of distance for the various high yield devices to be tested.
To extend measurements of spectrum distribution, particularly
in the region below ‘the sulfur threshold by using nuclear emulsions
to detect the fissions fragments from neptunium, uranium-238, and
urapiearaend
thorium detectors, all of ‘which have fission thresholds in the region
of 1 MEV.
Although the limite neutron flux data obtained for the IVY
detonztions indicate little significance for neutron radiation relative
to other effects from high yield.detonations, several considerations
indicate the importance of neutron measurements. Neutron flux does
ot scale simply with the KT equivalent of a device but both the flux
and spectrum are very dependent on ‘the, details of mechanical design of
a device. Knowledge of the neutrory‘flyx and spectrum is essential
for thorough analysis of weapons effetts.For example, such knowledge
is required for the interpretation of big dical effects of bomb
3.3.2
a
a an
radiation,
Procedure
:Fgust
i
i
Gold and tantalum detectors will be usedf‘for thermal flux
neasurenent and sulfur detectors (3 MEV
hyestiold) for fast neutrons,
using the techniques described in WT-524.the Pashbn threshold
detectors (uranium-238, thorium, and neptunium) usell| for measurement
of the flux in the region of 1 MEV will be calibrated against a known
flux from a Van de Graaff neutron source target and exposed’ in the
cavity of 4 cm and 8 cm wall lead spheres. A limited number of measure~
ments will be made on all shots at distances ranging from!.2500 to 5000
yd
from zero.
Stations will be spaced approximately 500“yd,.in a
range With several stations in a given direction and with 1 or 24
stations in different directions for some events. The use o
p39
detectors is contemplated.
1.
i
WT-524, Neutron FluxMeasurements, Operation TUMBLER-SNAPFER,
28