Evening star., 1940-04-25
BY THOMAS r. HENRY.

A giant x-ray apparatus, it's big
tubes projecting into cubicles with
walls of concrete a foot thick, now
is being set up at the United States
Bureau of Standards as a testing
station for the United States.
1t was described to the American
Physical Society, meeting at the
bureau today, by DR.. Lauriston S.
Taylor, chief of the X-ray division.
The generator, housed in high
chamber, will generate X-rays up
to 1900, 900 volts. This will make the
apparatus one of the most powerful
In the world. If these rays were
allowed to project from the mouths
OF the big guns" into the open
room they would be highly danger
Gus Tor all persons working in the
building. To obviate any danger the
tubes project into the concrete
cubicle which contains all the meas
uring apparatus and the targets
upon which the tests will be made.
Inside this cubicle is another with
walls Of concrete 16 inches thick
where the men actually working
With the apparatus vii be stationed.
Purpose of Tests.
The purpose of the setup, DR.
Taylor explained, will be to test the
actual effects of X-rays of various
Yoltages. Physicians are now ap-
preaching the point where dosages
as high as 100000 volts will be
given IN the treatment of cancer,
AT present. little is known about the
effects of rays propelled by such
terrific forces.
tests are not made, DR.. TAYLOR
explained, on actual biological ma
terlal. The Bureau of Standards
workers will determine the increase
OF electrical conductivity of the air
brought about by the X-rays passing
through it. This increase is due to
the fact that the hard, infinftesi-
mably small particles of radiation
strip electrons from air molecules
thus upsetting the electrical balance
OF the atmosphere. The degree of
1onlzatlon measured in the tests, DR.,
Taylor explained, can be fitted into
various formulae devised by biolo-
g1sts which describe the destructive
effect OF radiation on living cells.
Such highly penetrating radiation.
DR.. Taylor explained, probably would
prove rapidly fatal to any human
being exposed to them continuously
Tor any extended period.
Quick Cooling of Flame.
Possibility of cooling a flame as
hot as the surface of the sun to zero
almost instantaneously was ex-
planned to the physicists by DR.. C.
Guy Suits of the General Electric
Research Laboratory. He reported
that 00-degree hot sparks of a
high voltage electrical arc can be ex-
tlnguished by shooting electrical
"zeros' into them very rapidly, The
process is similar, it was explained.
to emptying bucket of cold water
over metal bearing to cool it. If a
direct current electrical circuit to a
motor suddenly becomes overloaded
the 10,000-degree sparks occur and
may burn up the metal parts of the
motor.
The danger can be averted. DR..
Suits said, within a fraction of a
second by use of a condenser which
momentarily reduces the electrical
current to zero and quenches the
sparks z !
A method of ayerting x-ray skin
burns from the new 1000, ,000-volt
tube installed at Memorial Hospital,
New York. was described by Drs. G.
Failla and Edith M. Quimby of the
hospital staff. Ordinarily this X-ray
dosage which can be used in treat
ing cancer is determined by the
reddening of the skin. More will
produce burns which are hard to
heal. The New York doctors simply
moved the source of the X-ray
beams further away from the part
Of the patient undergoing treat
ment. AS a result, the secondary
electrons, which cause most of the
burning, are scattered in the air and