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Blast Mtg Notes, 29 Dec 51

Ten cameras have been arranged for, and it was agreed that

the launching stations would be at the same places os Sandia's p(t) gauges,

omitting the first, very high pressure region and not going beyond Runit,

except for a station on Parry, with the camera also there. The reason for
this amount of coverage is essentially the same as for the Wiancko gauges-one would like to be able to draw a reliable pressure-distance curve. Also,
the effort at the launching stations is quite small, the major part of it
being the cameras.
Timing signals may be used where available, or a photocell
can be used to trigger the mortars. These require nothing but holes for
placement. Mortar velocities are about 150 ft/sec, time of flight ~ 5 sec.
J.

Measurements of Temperature, Air Absorption, Density,

Sound Velocity, etc.
The subject was raised of attempting to measure these related para-

meters which are quite important in evaluating and tying together the data

from ground and high altitude measurements. The Sandia group agreed that
such measurements would be quite valuable and thoughtthey might have at
least some effort to expend on them. They hope to try on the Snapper series
some equipment which may prove of use in measuring the temperature of the
air--we are specifically interested in this during the period after the bomb
goes off and before the shock hits the gauge--and could possibly use it on
Ivy if it turned out to be satisfactory.

The 6 densitometer might be used for measurements of density and
the amount of dust in the air. Cox suggested that Lenander's group could,
by getting the design of the successful one used at Greenhouse, make up the
equipment in time to use it on Snapper and again on Ivy. He felt they

could possibly try about four temperature and four density measurements in

addition to the items listed in Table I. Their doing it was suggested
because such measurements go with the ground stations and putting
a few more

channelsinthe recorderswould not be a major Job.7 However,
@ituation in Lenander'sgroup16nottlearat~
moment--at present he
does not have enough people toinstall half adozengauges.
—

(The Sandia group had to leave at this point, and it was agried

to discuss this with them again at a later time.)

Continuing the discussion, it is possible that Group J~10 has
enough effort to make at least the density measurement with the 6 densitometer . This device worked very satisfactorily on Greenhouse but with
one drawback--the effect of gamma rays.

One could not hope to get inside

the 8 = 10 psi region on a conventional bomb with this because of the gammas
in that region. However, on a super Porzel felt there was a chance of the
device's really coming into its own. Because of the longer time scale of
“2.
events, the relative time resolution would be better by at least a factor
,
of ten.

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