Evening star., 1955-03-12
Baby A-B|ast
Tests Use Of
SmokeScreen
Army Men Conduct
VitoI Experiment on
Reducing Radiation

LAD NEJAO, Nct., MAI. IL
Nevada's fifth atomic blast of
the 1855 series rocked and il
Illuminated the desert today while
the Army Chemical Corps con-
Quoted a vital experiment to de-
termine the power of a smoke
screen to cut down heat radia-
ton.
The detonation from a 300
foot tower at Yucca Flat came
at $40 am. CPST) 1920 am,
EST and was less than major
size. Observers in Las Vegas
classed it in the "baby A-bomb"
category.
The blast was seen as a bril-
liant, short white flash in Las
Vegas, about rs miles away. In
Los Angeles, some $50 miles dis
tant, the flash was like a faint
flicker of white light, resembling
a heat lightning flash.
Other Areas See Flash.
Other localities which saw the
flash included Phoenix, Ariz.,
where observers reported the
showing was considerably small
er than the March 7 blast, big
gest of the series. 1t was seen
family in the San Francisco
area.
After the detonation the
Atomic Energy Commission an
nounced that 35 tests of de-
velopment weapons and civil ef-
fects were conducted. OF major
interest was the test with a
smoke screen.
Acc officials said oil smoke
screen generators were estab-
lished on the upwind side of the
rim area. Previously it had been
announced that a smoke screen
about so feet in height would
be sent up by the Army Chemical
Corps to determine the ability
of such a screen to cut down
thermal Cheat) radiation on a
pOrLlOn OF Ine test SlGe.
Army officials have said that a
smoke screen can be used to pro-
tect vital areas from thermal
radiation of an A-bomb. How
ever, they added, use of smoke
screens will not stop the other
two effects-blast or pressure
wave and gamma radiation. The
gamma rays are the penetrating
ones and an overdose can cause
internal illness.
Study Reduction Means
Maj. Gen. William M. Greasy,
chief chemical officer of the
Army, recently announced that
the Army is studying means of
reducing gamma radiation.
During the blast today there
were various instruments around
the firing area to take data on
thermal radiation.
No troops participated in to-
days test. However. there were
65 aircraft in the air at the time
of the detonation. They were
primarily Navy planes of fighter
and dive-bomber types. All air
craft performed their missions
safely.
Personnel from Camp Desert
Rock was stationed at nine
different points in an observa-
ton exercise for the field ar
tillery.
The Acc said the atomic
cloud rose to height of $4,000
feet and was blowing in south
easterly direction. Acc officials
announced that a heavy shock
was felt at the control point,
the master center of all test op-
erations located at the edge of
Yucca Flat.
Some Doors Ratified
The shock of today's blast was
not generally felt in Las Vegas,
although there were reports that
some doors ratified. During
larger detonations the pressure
wave is distinctly felt in Las We
gas in about seven minutes after
the blast.
A half hour after the detona-
ton the rising clouds had
sheared into various layers of
Zig-zag pattern and .esembled
a lazy snake drifting in an east
ward direction over Nevada skies.
Photographers stationed at
Angels Peak. about As miles
from the test, said they heard
and felt the shock blast. They
said they saw part of the fire.
ball, but that mountains ap-
parently obscured some of it.