Starting in 1984, the following radioactivities were experimentally confirmed worldwide: 14C, 20O, 23F, 22,24-26Ne, 28,30Mg, and 32,34Si. The measured half- lives are in good agreement with theoretical predictions within the analytical superasymmetric fission (ASAF) model developed by Poenaru, W. Greiner, et al. Citations of papers published by D. N. Poenaru et al. on heavy particle radioactivities started in 1984 after the first experimental confirmation by Rose and Jones of the 14C radioactivity of 223Ra.
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Meitner's diploma bore the words: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies leading to the discovery of fission". Hahn's diploma was slightly different: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies culminating in the discovery of fission." Hahn and Strassmann were present, but Meitner was too ill to attend, so Frisch accepted the award on her behalf. During combined celebrations in Germany of the 100th birthdays of Einstein, Hahn, Meitner and von Laue in 1978, Hahn's narrative of the discovery of fission began to crumble.
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In September 1966 the United States Atomic Energy Commission jointly awarded the Enrico Fermi Prize to Hahn, Strassmann and Meitner for their discovery of fission. The ceremony was held in the Hofburg palace in Vienna. It was the first time that this prize had been awarded to non-Americans, and the first time it was presented to a woman. Meitner's diploma bore the words: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies leading to the discovery of fission".
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Hahn's diploma was slightly different: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies culminating in the discovery of fission." Hahn and Strassmann were present, but Meitner was too ill to attend, so Frisch accepted the award on her behalf. Glenn Seaborg, the discoverer of plutonium, presented it to her in the home of Max Perutz in Cambridge on 23 October 1966. Bust of Meitner by Thomas Baumann at the University of Vienna After her death in 1968, Meitner received many naming honours.
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Notices Roy. Astron. Soc., 234, 1-36 (1988); “On 26Al and Other Short-lived Interstellar Radioactivity”, Astrophys. J. (Letters) 415, L25–L29 (1993)] For scientific studies of the identities and the initial abundances of short-lived radioactive nuclei that remained alive at differing concentrations within the interstellar gas cloud that formed the solar system, but which are now extinct in the solar system, Clayton's factor (k+1) has grown in importance owing to experimental discoveries of many such nuclei within the meteorites. These are called the extinct radioactivities because none remain on earth today but which did leave clear evidence of their prior existence in meteorites.
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Of the three types of naturally occurring radioactivities (α, β, and γ), only alpha decay is a type of decay resulting from the nuclear strong force. The other proton and neutron decays occurred much earlier in the life of the atomic species and before the earth was formed. Thus, alpha-decay can be considered either a form of particle decay or, less frequently, as a special case of nuclear fission. The timescale for the nuclear strong force is much faster than that of the nuclear weak force or the electromagnetic force, so the lifetime of nuclei past the drip lines are typically on the order of nanoseconds or less.
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It has been conjectured that such a device could serve as a "doomsday weapon" because such a large quantity of radioactivities with half-lives of decades, lifted into the stratosphere where winds would distribute it around the globe, would make all life on the planet extinct. In connection with the Strategic Defense Initiative, research into the nuclear pumped laser was conducted under the DOD program Project Excalibur but this did not result in a working weapon. The concept involves the tapping of the energy of an exploding nuclear bomb to power a single-shot laser which is directed at a distant target. During the Starfish Prime high-altitude nuclear test in 1962, an unexpected effect was produced which is called a nuclear electromagnetic pulse.
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Clayton introduced the idea that the relative abundances of the isotopes in tiny solid dust grains that condensed within hot gas leaving individual stars would be observable in such single dust grains. Those grains reveal the isotopic composition of their parent stars. He named these solids stardust,Precondensed Matter: Key to the Early Solar System, Moon & Planets 19, 109 (1978) postulating thereby a new component of interstellar Cosmic dust. Stardust inherits its unusual isotopic compositions from the evolved nuclear composition of the parent star within which that grain condensed. Clayton's initial steps[ “Extinct radioactivities: Trapped residuals of pre-solar grains”, Astrophys. J., 199, 765-69, (1975); “22Na, Ne-E, Extinct radioactive anomalies and unsupported 40Ar”, Nature, 257, 36-37, (1975) focused on large isotopic excesses in supernova dust grains owing to decays of abundant short-lived radioactive nuclei that were created in the nuclear explosion and then condensed within a few months in the cooling ejecta; but it was generalized to all types of stellar mass loss in 1978.Donald D. Clayton, Precondensed Matter: Key to the Early Solar System, Moon & Planets 19, 109 (1978); "Grains of anomalous isotopic composition from novae", Clayton & Hoyle, Astrophys.J. 203, 490 (1976); “Cosmoradiogenic ghosts and the origin of Ca-Al-rich inclusions”, Earth and Planetary Sci. Lett.
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