Evening star., 1947-12-27
Scientists Describe
Production Of New
Radioactive Elements
BY Thomos R. Henry
Stor Stoff Correspondent

Of an entirely new family of radio
active elements, none of which exist
in nature and at least one Of which
promises to be of great Importance
for the future of atomic energy was
announced here today.
The series is produced by bonn
harding the heavy, exploding ele-
ment thorium with atomic cannon
balls-nucleii of helium and double
hydrogen atoms-in cyclotron.
The work was carried out with the
utmost secrecy during the war and
hitherto has not been revealed.
The synthesis was described be-
fore a section meeting of the
American Association for the Ad-
vancement of Science by Drs. Leon
ard J. Katzin, M. A. Studier and E.
Hyde of the Atomic Energy Com
missions Argonne laboratory at the
University of Chicago.
Chain Reaction Uncertain.
The family includes new forms
of the synthetic trans-uranium ele-
ments neptunium, plutonium, and
Americum, as we'll as of uranium
and thorium themselves. BY far the
most important, however, is a
lighter isotope Of uranium which,
tests have shown, Is fashionable by
bombardment with slow neutrons in
the same way as uranium 235 and
plutonium, the essential elements
of atomic energy. Whether a chain
reaction can be set up in this new
found uranium 233 was not re-
vealed, but DR.. Katzin described it
as "a possible nuclear fuel in large
scale atomic energy production.
Since it is formed by the action of
neutrons on thorium one can In
essence use that element, Of
abundance greater than uranium,
as a nuclear fuel source"
He indicated that much research
will be necessary before this use will
be practical. Thorium from the first
has been an illusory factor in the
atomic energy picture. Some OF the
largest known deposits are in the
Southern Appalachians. The United
States has no known large uranium
deposits and will always be a de-
pendent country so far as this ele-
ment is concerned. II the promises
reported today are borne out, the
amount of atomic fuel in the world
would be essentially doubled.
Second Heaviest Element.
&c conor1 hnoUincf Nf
the elements and in nature, like
uranium, it eventually disintegrates
into lead. 1t has been mined COM
mercially for many years, Its great
est use being in the manufacture Of
gaslight msntles. One Of the big
gest scares of Manhattan Project
officials during the war came when
they learned that the Germans had
requisitioned all the thorium in
France. 1t was feared that the
enemy had found some way of set
ting I'D a chain reaction with the
element, but this proved false
alarm.
SynthesiS of the new radioactive
family resulted also in the produc-
tion for the first time Of the two
metallic elements, francium and as
tatine. These never have been
found in earth, although they are
necessary to fill in the atomic table.
They can only exist, it was shown,
as members Of this new "protac-
tinium" series. Another member of
the new family Is an extremely light
isotope Of uranium, U-230, which
has half life of about 81 days
The Investigators also found a new
form Of thorium which only remains
in existence half hour.
All Of the family may fit some
where into the eventual atomic
energy picture. but the discovery is
so new that there has been little
opportunity to study their proper
ties. DR.. Katzin suggested accumu-
lating large stockpile Of U 233
Even If 1t is not used for atomic
energy, he said, it will be valuable
as a starting point for other mem
bers of the series which may find
important uses in medicine and
other fields. 1t cannot be produced
It was stressed, from the common
form Of uranium, from which there
Is no chemical means of separat-
ing it.
Evidence that the solar system
once contained a tenth planet in
an orbit between Mars and Jupiter
which exploded several hundred
years ago was presented before the
association by Dr. Harrison Brown
Of the University of Chicago and
DR.. Carl A. Bauer Of the University
of Michigan.
Virtually all the meteorites which
ever have struck the earth are frag-
ments of this planet, they said. The
causes of the cosmic catastrophe are
entirely unknown. A difficulty with
any such theory in the past has been
that analysis of meteoric stones and
metals has shown varying amounts
of helium, which is created by the
breakdown of uranium. This indi-
Gated that the fragments were of
different ages. 1t now develops, DR..
Bauer said. that helium can be Gre
ated by bombardment with cosmic
rays so it offers no guide as to the
age of a specimen
The exploded planet was recon-
structed' from the evidence of the
meteorites as comparable in size to
the earth, with a molten core Of
nickel-iron at about 5000 degrees
centigrade.