From: Lawrence Johnston (email@example.com)
Date: Sun Jun 01 2003 - 09:52:42 EDT
Moorad - thank you for the information on your Advisor, Emil
Konopinski, and his calculations of the D-T reaction. Emil was a
good friend of MY thesis advisor, Luis Alvarez. I think I met
Emil at a party at Alvarez' house, in 1944. His calculations
were good, but I guess Oppenheimer did not sufficiently trust
their calculations of the Fat Man bomb's energy release.
Just as Alvarez and I (and Wolfgang Panofsky) were about to take
off in our instrumented B-29 to make measurements of the Trinity
test, July 16, 1945, Oppenheimer called Alvarez and ordered him
to stay at least 25 horizontal miles from the Alamogordo Trinity
test site, since he felt unsure of the bomb's energy output. We
were planning to use the Trinity explosion as a dress-rehearsal
for our soon-to-come measurements of the energy output of the
bombs that were later dropped on Hiroshima and Nagasaki. Our
measurements were not needed for the Trinity test itself, since
there was a large amount of instrumentation on the ground. Most
of those detectors were blown up in the explosion, but not before
their output was recorded remotely behind the personnel bunkers.
We took off anyway from Kirtland Airforce base, and went through
our routine drop of parachute gages at 30,000 feet altitude,
while we listened by radio to the countdown from the ground
bunker for the explosion on top of the steel tower. When the
bomb went off as hoped for, all of us were thankful that our
particular components of the Implosion system worked. If it had
fizzled, we would forever since have wondered if the fizzle was
our fault. And of course I was thanking The Lord. Alvarez was an
atheist so I don't know whom he was thanking.
Thanks, Moorad. Larry Johnston
Lawrence H. Johnston home: 917 E. 8th st.
professor of physics, emeritus Moscow, Id 83843
University of Idaho (208) 882-2765
Fellow of the American Physical Society
Moorad Alexanian wrote:
> It was Emil J. Konopinski, my PhD thesis advisor, who suggested when
> at Los Alamos the use of D-T (deuterium-tritium) rather than D-D
> reaction for the atomic bomb owing to the larger cross section of the
> D-T reaction. He was also the one who calculated that the explosion of
> an atomic bomb in the atmosphere would not ignite the atmosphere; such
> were the fears and the unknowns of the early nuclear efforts.
> Tritium http://www.triumf.ca/safety/rpt/rpt_8/node8.html
> _____ > Tritium is an isotope of hydrogen which has one proton and
> two neutrons . It emits beta particles only and has a half-life of
> 12.3 years. The maximum beta energy is 18 keV, and the mean beta
> energy is 6 keV. A beta particle with energy of less than 70 keV will
> not penetrate the dead outer layer of the skin. Therefore, tritium is
> not an external radiation hazard , but when taken into the body it
> becomes an internal hazard .
> Tritium is produced in accelerator cooling water systems which are
> subjected to large proton or neutron fluxes such as those of the meson
> production targets of the TRIUMF 500 MeV facility. The tritium is
> produced by spallation reactions with oxygen, nitrogen and carbon
> nuclei present in the water systems and to a much lesser degree by
> radiative capture of neutrons by the deuterium nuclei in water. The
> tritium atom then combines with a hydrogen and oxygen atom to form
> the molecule HTO, often called tritiated water.
> Tritium does not contribute any significant part of the dose at
> TRIUMF, and most uptakes would be acute rather than chronic.
> Uptakes of tritium usually result from inhalation and skin absorption,
> but ingestion is also possible. The blood distributes tritiated water
> equally among all the body fluids, just as it does with normal water.
> All the soft tissues in the body will be irradiated by the decaying
> tritium and they constitute 90% of the body weight. As a result any
> tritium in the body will lead to a whole body equivalent dose .
This archive was generated by hypermail 2.1.4 : Sun Jun 01 2003 - 09:52:37 EDT