radioactive decay rate

radioactive decay rate

The time rate of the disintegration of radioactive material generally accompanied by the emission of particles and/or gamma radiation.
Dictionary of Military and Associated Terms. US Department of Defense 2005.
References in periodicals archive ?
[11-13] which reported characteristic histograms for the decay of Pu-239 which were periodic over a 24 h interval (the solar day, thus the spin of the Earth), a ~28 day interval (the lunar month, thus the period of the Moon), and the sidereal year, and also reported characteristic histograms of radioactive decay rate associated with a New Moon and a total solar eclipse.
This interruption of neutrinos, due to the nucleons of Jupiter scattering and inelastically capturing some small, but non-trivial, proportion of particles and/or radiation causes a decrease in radioactive decay rate because of the consequent decrease in the particle flux transferring momentum to the nuclei of Po-210.
On 4 Dec 2002, a total solar eclipse occurred, during which the radioactive decay rate of Co-60 was measured at Pittsburg State University in southeastern Kansas [17], and the radioactive decay rate of Po-210 [18] was measured in the Boston area, both at/near the time of totality in southern Australia.
Using tree-ring time data, sediment core analyses from bodies of water, and ice layer dating from Greenland, he suggested that "comparisons of [these] ice core dates, radiocarbon dates, and uranium-thorium dates indicate that there were several periods in the late Pleistocene and early Holocenc when abnormally large ratios of [carbon-14] effectively counterbalanced the radioactive decay rate, such that radiocarbon ages appear to remain constant over centuries ...
It takes a unique approach of comparing raw carbon-14 data (no use of calibration curves) with tree-ring counts back to 14,000 years (most from Europe), and annual sediment layer (varve) counts covering 50,000 years of sediment deposition in Lake Suigetsu, Japan, to show how assumptions such as constant radioactive decay rates, annual growth of tree rings, and annual deposition of layered sediments can be tested and verified.
The controversial findings suggest that radioactive decay rates - long considered physical constants - may be more variable than previously thought.
The new detection technique is based on a hypothesis that radioactive decay rates are influenced by solar activity, possibly streams of subatomic particles called solar neutrinos.
Since 1907, numerous experiments have shown that radioactive decay rates do not change through chemical or physical processes.
By combining independent measurements such as counts of tree rings, counts of lake-sediment couplets that appear to be annual deposits, and carbon-14 content, we can demonstrate beyond reasonable doubt that the trees put on one ring per year, the sediments in question formed annual layers, radioactive decay rates have not changed over time, estimates of past atmospheric production of carbon-14 are accurate, and the history of [INCOMPLETE IN ORIGINAL SOURCE.]
The idea that radioactive decay rates have been significantly different in the past is strongly contradicted by experimental data and theoretical analysis.