GrFICIAL
USE GNLY
HEADQUARTERS
cells
TASK GROUP 7.1
JOINT TASK FORCE SEVEN
AOAIE
APO femcommax 437
SAN FRANCISCO, CALIFORNIA
2833 JFE
Bp
May 21, 1956
Dr. Thomas L, Shipman
University of California
Los Alamos Scientific Laboratory
P. 0. Box 1663
los Alamos, New Mexico
Dear Tom:
Had intended to get something off long before this.
We've
grabbed everything up on two occasions and dashed off to sea.
After rattling around for two or three days, we have to give up
amd come back.
Si and Ed arrived in good shape while we were off on our last
such jaunt, Both of them were after me for not writing sooner, as
was Gordon with his letter from you. Will try to catch you up with
things that happened before we started off on the first such trip.
Am enclosing a hodograph and some readings as interpreted
from various sources. As you can see from the hodograph, the mean
speed of the stuff from 30-40,000 is something like 5 knots,
The
first survey party got into the air at something like H plus 1,
and ran into it at the northern end of the atoll. They came back
slightly warm, about 1.6 R dose, and a couple of warm choppers.
We've had a few problems come up, have been able to straighten
them out without much trouble, The blank density of the film
appeared to have gone up to about .39. We were afraid it had aged
rapidly, or had been flashed by a source some place in transit.
Finally pinned it down to processing procedure. They had been
using a wetting agent before putting the film into the developer,
and had not been mixing the hardner into the developer.
The use
of one and the lack of the other both contributed to the increased
density. Proper processing now gives us a blank of 0.19, about
what you get there at home.
Fall-out forecasting has been satisfactory to date.
The
Sandia machine is working fine here, and we now hav2 the NBS-Weather
Bureau machine functioning on board the ship. Both are useful tools,
but a certain amount of judgment must be used in interpreting their
results,
The optical machine has not operated satisfactorily yet.
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