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TOPIC: Proton Radioactive Decay
Blobrana


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Nuclear Decay Rates
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Title: Further Evidence Suggestive of a Solar Influence on Nuclear Decay Rates
Authors: Peter A. Sturrock, Ephraim Fischbach, Jere H. Jenkins

Recent analyses of nuclear decay data show evidence of variations suggestive of a solar influence. Analyses of datasets acquired at the Brookhaven National Laboratory (BNL) and at the Physikalisch-Technische Bundesanstalt (PTB) both show evidence of an annual periodicity and of periodicities with sidereal frequencies in the neighbourhood of 12.25 year^{-1} (at a significance level that we have estimated to be 10^{-17}). It is notable that this implied rotation rate is lower than that attributed to the solar radiative zone, suggestive of a slowly rotating solar core. This leads us to hypothesize that there may be an "inner tachocline" separating the core from the radiative zone, analogous to the "outer tachocline" that separates the radiative zone from the convection zone. The Rieger periodicity (which has a period of about 154 days, corresponding to a frequency of 2.37 year^{-1}) may be attributed to an r-mode oscillation with spherical-harmonic indices l=3, m=1, located in the outer tachocline. This suggests that we may test the hypothesis of a solar influence on nuclear decay rates by searching BNL and PTB data for evidence of a "Rieger-like" r-mode oscillation, with l=3, m=1, in the inner tachocline. The appropriate search band for such an oscillation is estimated to be 2.00-2.28 year^{-1}. We find, in both datasets, strong evidence of a periodicity at 2.11 year^{-1}. We estimate that the probability of obtaining these results by chance is 10^{-12}.

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Blobrana


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RE: Proton Radioactive Decay
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Solar ghosts may haunt Earth's radioactive atoms
It's 1986, and there's a puzzle on Dave Alburger's desk. Not Ernö Rubik's latest toy, but the data from a four-year experiment to measure the half-life of the rare radioactive isotope silicon-32. On one level, the numbers fit together just fine, adding up to a half-life of 172 years, in keeping with previous estimates.
There's a devil in the detail, however. The sample's radioactivity has not been dropping steadily over time, as the textbooks demand. It has fallen, to be sure, but superimposed on that decline is an odd, periodic wobble that seems to follow the seasons. Each year, the decay rate is at its greatest around February and reaches a minimum in August.

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Blobrana


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Physicists are stirred by claims that the sun may change whats unchangeablethe rate of radioactive decay
Its nuclear physics 101: Radioactivity proceeds at its own pace. Each type of radioactive isotope, be it plutonium-238 or carbon-14, changes into another isotope or element at a specific, universal, immutable rate. This much has been known for more than a century, since Ernest Rutherford defined the notion of half-lifethe time it takes for half of the atoms in a radioactive sample to transmute into something else. So when researchers suggested in August that the sun causes variations in the decay rates of isotopes of silicon, chlorine, radium and manganese, the physics community reacted with curiosity, but mostly with scepticism.

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Blobrana


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Posts: 131433
Date:
Nuclear Decay Rates
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Title: Perturbation of Nuclear Decay Rates During the Solar Flare of 13 December 2006
Authors: Jere H. Jenkins, Ephraim Fischbach

Recently, Jenkins, et al. have reported the detection of correlations between fluctuations in nuclear decay rates and Earth-Sun distance, which suggest that nuclear decay rates can be affected by solar activity. In this paper, we report the detection of a significant decrease in the decay of 54Mn during the solar flare of 13 December 2006, whose x-rays were first recorded at 02:37 UT (21:37 EST on 12 December). Our detector was a 1 uCi sample of 54Mn, whose decay rate exhibited a dip coincident in time with spikes in both the x-ray and proton fluxes recorded by the GOES-10 and 11 satellites. A secondary peak in the x-ray and proton fluxes on 17 December at 12:40 EST was also accompanied by a coincident dip in the 54Mn decay rate. These observations support the claim by Jenkins, et al. that nuclear decay rates vary with Earth-Sun distance.

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Blobrana


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Posts: 131433
Date:
Proton Radioactive Decay
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Radioactivity, discovered more than 100 years ago and studied by physicists ever since, would seem to be a relatively closed subject in science. However, since the 1960s, the pursuit of at least one open question about how nuclei spontaneously eject various particles has continued to nag experimentalists, largely because of an inability to make precise measurements of fleeting, exotic nuclei.
In a paper published this week in Physical Review Letters, an international collaboration of researchers, led by Marek Pfutzner, a physicist from Warsaw University in Poland, takes several steps toward an answer. The scientists describe a first-ever success in peering closely at radioactive decay of a rare iron isotope at the ragged edge of the known nuclear map. The tools used to achieve this result include a novel combination of advanced physics equipment and imaging technology that is found in most off-the-shelf digital cameras.

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