Re: Eyes on the sun: Naked thallium-205 ion decay reveals history over millions of years

On 14/12/2024 4:24 pm, Jan Panteltje wrote:

Eyes on the Sun: Naked thallium-205 ion decay reveals history over millions of years
  https://www.sciencedaily.com/releases/2024/12/241211124824.htm
Source:
  GSI Helmholtzzentrum für Schwerionenforschung GmbH
Summary:
  The Sun generates its tremendous energy through the process of nuclear fusion.
  At the same time it releases a continuous stream of neutrinos --
  particles that serve as messengers of its internal dynamics.
  Although modern neutrino detectors unveil the Sun's present behavior,
  significant questions linger about its stability over periods of millions of years.
  Finding answers to this is the goal of the LORandite EXperiment (LOREX).
 So now we can find out the history of the sun, and its influence on our climate.
 Will be interesting to see some fairytales destroyed :-)

Jan hasn't noticed that it is his fairy tales that are at risk.
His report is about an experiment designed to infer "a precise knowledge of the solar neutrino cross section of thallium".
"Neutrinos produced in our Sun interact with thallium (Tl) atoms, present in the lorandite mineral (TlAsS2), and convert them into lead (Pb) atoms. The isotope Pb-205 is particularly interesting due to its long half-life time of 17 million years".
"As it is currently not feasible to directly measure the neutrino cross-section of Tl-205, researchers at GSI/FAIR in Darmstadt, Germany, came up with a clever method to measure the relevant nuclear physics quantity needed for the determination of the neutrino cross section. They exploited the fact that this quantity, the nuclear matrix element, also determines the bound-state beta decay rate of fully ionized Tl-205 81+ to Pb-205 81+."
So the idea is that the quantity of Pb-205 in the lorandite deposits is a weighed average of the of the number of solar neutrinos that have hit the deposit over the last four million years or so, not exactly a fine-grained account of the nuclear fusion rate in the core of the sun over that sort of period.
--
Bill Sloman, Sydney