Evening star., 1949-02-07
OF Stars, Men and Atoms
New Instrument Devised
To Detect Atom Radiation
'Scintillation Counter Is Compact.
Light, Sturdy and Accurate
By Thomas r. Henry

| By Thomas r. Henry
Development of new instrument for de.
tecting atomic radiations which might be.
come essential military equipment in another
war has just been announced by the Atomic
Energy Commission.
1t is extremely light. compact and essen
TALLY infallible and is known as "scintilla-
ton counter" It is based on a new physical
principle
The common means of detecting and
measuring radiations is the so-called Geiger-
Mueller counter. When an atomic particle
passes through gas outer electrons are
knocked of atoms and a minute current is
set up which can be magniied and heard
as click" It Is a rather cumbersome in.
strument. difficult to build and interpret.
and somewhat expensive. 1t is hardly
adapted for the average soldier or civilian
defense worker. A major drawback is that
1t does not give an accurate measure Of
neutron radiation. the most dangerous Of
all In the vicinity Of bomb explosion.
Accurate Measurement Possible.
Commission physicists have found that
crystals OF two substances made out Of coal
tar give an accurate measure Of all kinds Of
radiation. These materials are stilbene and
anthracene. When an elementary particle
hits such a crystal there is a flash OF short
duration and relatively high intensity. This
flash can be picked up and amplified by a
special type Of photomultipler tube and
translated into a pulse Of electric current
which can be registered on earphones or
mechanical counters. Eventually it may be
made into an instrument no larger than q
watch which is quite unlikely to get out
of order.
There still remain bugs" in the instru-
naent, the commission physicists admit, and
much work remains to be done, especially
in developing methods for production Of
pure crystals
Various other types of crystals are under
test. Some variation in the magnitude Of
the flashes with different temperatures has
been found. The investigation is being
pushed at all five major laboratories Of the
commission.
A special advantage, it is pointed out Is
that the scintillaton counter appears to he
entirely reliable for detecting and measuring
the elusive neutron radiation.
Two atom -SmasherS of unprecedented
power are being built under the auspices
of the Atomic Energy Commission.
Compared to this new heavy artillery
OF the invisible world of the atom, any of
the great cyclotrons. synchrotrons and be-
tatrons now in existence-on which has
depended much of the progress of atomic
research-will be like rifles compared to
hoWitZerS.
Both new machines are known as 'proton
synchrotrons." Of essentially the same fam
lily as the cyclotron. The largest of these
will be at the University of California where
the cyclotron was born. 1t is expected to
cost $9,000000 and be four or five years
under construction. 1t will have 5000.
100000 electron volt output l8 times more
powerful than the greatest atom smasher
in use at present. 1t will attack the atomic
nucleus with energies so far beyond today's
range that its designers are unable to pre-
dict the nature of the facts it may un.
cover.
Synchrotron Being Built.
Less powerful. but of the same general
type Of construction is proton synchrotron
now under construction at the Brookhaven
National Laboratory on Long Island. It
will accelerate nuclear particles to energies
about seven times the greatest achieved
today.
Also under construction at Brookhaven Is
the largest Of the great uranium ovens, or
piles" which will serve entirely as q tool
for research. In this pile will be produced
host OF isotopes, or different forms of ele.
ments for which there is a great demand
IN the country's universities.
Greatest of the piles now in operation Is
at Oak Ridge, Tenn, where the greatest
part OF the radioactive material now in use
is being produced.