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Xenon-135 (135 Xe) is an unstable isotope of xenon with a half-life of about 9.2 hours. 135 Xe is a fission product of uranium and it is the most powerful known neutron -absorbing nuclear poison (2 million barns ; [ 1 ] up to 3 million barns [ 1 ] under reactor conditions [ 2 ] ), with a significant effect on nuclear reactor operation.
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
Because 95% of the xenon-135 production is from iodine-135 decay, which has a 6- to 7-hour half-life, the production of xenon-135 remains constant; at this point, the xenon-135 concentration reaches a minimum. The concentration then increases to the equilibrium for the new power level in the same time, roughly 40 to 50 hours.
Xenon-136 is an isotope of xenon that undergoes double beta decay to barium-136 with a very long half-life of 2.11 × 10 21 years, more than 10 orders of magnitude longer than the age of the universe ((13.799 ± 0.021) × 10 9 years). It is being used in the Enriched Xenon Observatory experiment to search for neutrinoless double beta decay.
Xenon-136 is produced when xenon-135 undergoes neutron capture before it can decay. The ratio of xenon-136 to xenon-135 (or its decay products) can give hints as to the power history of a given reactor and the absence of xenon-136 is a "fingerprint" for nuclear explosions, as xenon-135 is not produced directly but as a product of successive ...
In 1975 it was estimated, by George Chapline and Lowell Wood from the Lawrence Livermore National Laboratory, that “pumping a 10-keV (0.12-nm) laser would require around a watt per atom” in a pulse that was “10 −15 seconds x the square of the wavelength in angstroms.” As this problem was unsolvable with the materials at hand and a ...
Matthew Stewart got airlifted off Half Dome in Yosemite and discovered he had a brain tumor. A year later, he went back and made it to the top. A Brain Tumor Stopped This Guy From Doing an 8,800 ...
In this situation it is generally uncommon to talk about half-life in the first place, but sometimes people will describe the decay in terms of its "first half-life", "second half-life", etc., where the first half-life is defined as the time required for decay from the initial value to 50%, the second half-life is from 50% to 25%, and so on.