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2

The idea that you propose is possible. In fact, there is a very famous example of your setting: the Wu experiment. Chien-Shiung Wu at the US National Bureau of Standards prepared a thin surface of ${}^{60}Co$. This isotope decays by beta decay, producing one electron and one antineutrino. Due to the small magnetic moment of the nuclei, they had to cool the ...


8

To be honest, the paper listed as reference 12 in the OP's quote (1) gives as good an answer to most of these questions as you can hope to get: For example, taking $\omega(E)$ as a Lorentzian function for all E yields the well-known exponential decay at all times. However, in real physical systems, $\omega(E)$ must always have a lower limit, which ...


0

Physics is about quantified observations of nature, modeled mathematically. The mathematical models are rigorous and self consistent but in order to connect to measurements extra postulates are needed, which define the connection of the mathematical formulae to data. Laws are parts of these postulates. In the same way that axioms are not provable within a ...


0

Maybe your are looking for a more physical explanation. Imagine you have a material that consists of identical atoms. The atom cores are not stable and therefore we call the material radioactive. With quantum mechanics you can calculate the probability that a atom core that has not decayed yet will decay. If you do this you will find a constant probability!...


2

A scientific law is a statement that concisely states an observation about nature that is true for a wide variety of situations. The important part is that the statement is about observations and experiments; it is not an attempt to explain the phenomena. That's a theory's job. For example, the law of conservation of mass is true for all chemical reactions. ...


-1

Pu 239 can be put in highly toxic radioactive isotopes. As you know radio isotopes are mostly generated from the radioactive decay reactions and the heaviest material naturally occurring is U238. Pu239 is mostly created in artificial nuclear reactions. The danger of the radio isotopes is measured by their half lives. Radio isotopes having longer half ...


3

The very flexibility that you mention in your post is a bit of a problem in an experimental context. In order to understand the signal that a Cf-Be calibration source would generate in your detector and tease useful information out of it, you're going to have to model all three channels that generate neutrons and the gammas that escape the source. This means ...


4

The earliest reference I've been able to find on the half-life of 235U is in The Uranium Half-Lives: A Critical Review, by Norman Holden, which reviews various early studies of each of the common isotopes of uranium (232U, 233U, 234U, 235U, 236U, and 238U). The earliest study he cites is Nier (1939) (A. 0. Nier, The isotopic constitution of uranium and the ...


1

I am adding a few points that Lawrence's answer didn't yet address, but should help clarify the nature of the quantum tunneling process: According to the QM postulates, the unitary evolution of such a system should by definition keep it reversible, so it is only when measured that a decay can be observed or not. But this would make the decay rate ...


2

I thought I would indicate how radiactive decay can be argued to occur from quantum tunneling. This derives in a very “back of the envelope” way the phenomenological equation for radioactive decay. From there I can argue some about the role of observing radioactive decay. Quantum tunneling can be see with the square potential barrier. A square potential ...



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