Evening star., 1952-09-27

KUUUI WUIISIeI THS
Letha| Rays as Navy !
Tests Effects Of Burns
"The monster" they call this
7,000-pound jug Of death.
In it is packed the killing power
of half the radium on earth. It
is the most sinister part of re-
nnarkable robot, displayed for the
first time yesterday at the Naval
Medical Research Institute, whose
60 shutting tubes produce much
of the killing effect Of an atomic
bomb explosion due to radiation.
Each of the tubes contains al
minute amount of cobalt CO." al
radioactive form Of the iron-likeI
metal, which has had much pub
licity during the last two years.
as substitute for radium.
In some ways, it is superior tol
radium, although at present Gov
ernment prices it costs only about
one four -thousandth as much. I'll
can be produced in as great guam
titles as ever will be needed
eventually at least.
The purpose Of the Navy's robot
Is to study, with animals rangingl
in size from pigmy white mice tol
goats and fat pigs. the effects oil
total body radiation" such asI
anybody would receive standingl
unsheltered within a mile or sol
of an atomic bomb explosion.
Little Known Now.
In the past a lot has been writ
ten about this, but very little
actually has been known. The
only material for such studies has
consisted of the japanese victims
in Hiroshima and Nagasaki and
some pigs and goats exposed at
various distances from expert
mental bomb explosions in the
Pacific.
A great deal about partial effects
has been learned from use of x
rays. There have been two major
difficulties.
First. with X-rays it has been
impossible to irradiate more than
small parts of the body. usually
specific organs, atone time. There
has been no way to determine
the effects on the body as a whole.
To produce such a robot as was
revealed yesterday, with X-ray
tubes as a source of radiation,
would be inordinately expensive
both from the initial cost of the
tubes and the cost of frequent re-
placement.
Presumably the exploding CO.
bait" tubes will last for at least
five years without any replace
ments. That is about the half
life of the material-that is, the
period during which half of any
lgiven number Of atoms will have
blown up.
Special Concrete Walls.
At the Navy's Bethesda radia-
ton laboratory. there are two ex-
lposure rooms, each lined with
thick walls Of a special type of
concrete. In one Of these rooms
lis "the monster" A robot mag
Inetic arm, operated entirely by
remote control through a peri
scope, takes Off the heavy lid of
the job. picks up the hot tubes of
cobalt. one by one, places them in
other tubes and screws on the lids
and then places them in an ex-
tremely complicated pneumatic
tube system, which shuttles them
into the other exposure room.
This picking up, screwing and
loading through the periscope with
the aid of mirrors is itself one of
the most delicate jobs imaginable.
Once in place in the exposure
room, the tubes are so arranged in
the form of a cylinder that an
animal inside the cylinder will
get a uniform, heavy. eventually
lethal radiation over the entire
body. The cylinder is big enough
to contain a large pig. The only
creatures there yesterday were
two tiny white mice in a cage.
Precise Timing.
The amount Of radiation re-
ceived depends on time of ex-'
posure, within a matter of Sec
onds. The apparatus will deliver
80 roetgens of radiation per min
ute, not enough to seriously injure
anybody, or about 1000 roetgens
an hour, enough to kill anything
on earth. The operations of the
robot are timed precisely.
In a split second after enough
radiation energy has been given
for the purposes of the expert
ment, button is pressed and the
cobalt tubes are carried by the
pneumatic system back to the
other exposure room, the one con-
tanning the monster"
Then the room in which the ex-
pertinent has taken place is per-
fectly safe for the scientists to
enter. They can clean up and get
things ready for another expert
ment. An instant before it was a
room of invisible death.
The cobalt delivers radiation of
only one wave length, with the
penetrating power of a million
volts. This is in the extremely
short X-ray range. It is clearly
in the spectrum of gamma rays,
which are the most dreaded part