A nuclear reactor made to produce specific isotopes rather than just consume fissile material to produce electrical power. The most notably application being to produce Plutonium-239 for nuclear weapons from Uranium-238 being irradiated from Uranium-235-created fission.
Tome of the Comptes rendus de l'Académie des Sciences by
Ciro Santilli 35 Updated 2025-04-05 +Created 2024-08-14
Weapon grade Plutonium is cheaper than weapon grade Uranium by
Ciro Santilli 35 Updated 2025-04-05 +Created 2024-08-14
Because you can generate plutonium-239 from uranium-238 in a breeder reactor, and then separate the plutonium-239 from the Uranium simply by using chemistry methods because you've created an element with different valence electrons.
Isn't it somewhat funny that it is easier to purify a synthetic element than a naturally occurring one?
This isotope shows up as an inevitable contaminant in Plutonium-239 for nuclear weapons, because it emits neutrons too fast and makes it harder to assemble the critical mass without fizzle.
It is the presence of this contaminant that made implosion-type fission weapon a necessity: Section "Gun-type fission weapons don't work with plutonium".
Plutonium-240 is a contaminant.
Strong alpha emitter. Can be used as an atomic battery.
Plutonium-238-oxide pellet glowing under its own heat
. Source. Unlike for nuclear applications, we don't need the pure metal, so the oxide 238PuO2 is used instead as it is more chemically stable. S-50 liquid thermal diffusion plant by
Ciro Santilli 35 Updated 2025-04-05 +Created 2024-08-14
Y-12 electromagnetic separation plant by
Ciro Santilli 35 Updated 2025-04-05 +Created 2024-08-14
These are neutrons that have reached the thermal equilibrium according to the Maxwell-Boltzmann distribution after having bounced around many times without undergoing neutron capture.
Good fissile material is material that is able to absorb thermal neutrons and continue the reaction, because that's the type of neutron you end up getting the most of.
Uranium-235 neutron cross section as a function of neutron energy
. Source. Neutron cross section for various uranium isotopes
. Source. This isotope separation method was the first big successful method, having been used in the Manhattan Project, notably in the K-25 reactor.
This method was superseded by the more efficient gas centrifuges.
Gaseous diffusion diagram
. Source. Comptes rendus de l'Académie des Sciences by
Ciro Santilli 35 Updated 2025-04-05 +Created 2024-08-14
Apparently there were biweekly reports, that were grouped and published biannually on January and July, each one with a sequential tome number.
For example, both Marie Curie's Polonium paper and Marie Curie's Radium paper were published in the second half of 1898 and fell in tome 127.
Public domain publication list: archive.org/search?query=comptes+rendus+academie+des+sciences&sort=-date&and%5B%5D=collection%3A%22pub_comptes-rendus-hebdomadaires-academie-des-sciences%22 but some years are randomly missing like 1898?
OK from here you can find all of them more clearly: www.academie-sciences.fr/en/Transmettre-les-connaissances/comptes-rendus-de-l-academie-des-sciences-numerisees-sur-le-site-de-la-bibliotheque-nationale-de-france.html
TODO how to download a PDF from? I can't even turn the pages...
There are unlisted articles, also show them or only show them.