Physics, Astronomy & Cosmology / Re: Is the photon model of electromagnetic wave an oversimplification?« on: 25/07/2021 23:34:27 »
Quote from: acsinuk
each unit contains the power = hf Cos ϴ.of energy per second.This sounds like a solar panel.
Quote from: hamdani yusuf
I think you know how neutrino was discovered. How do you make sure that no neutrino is produced in the process?I didn't know how neutrinos were first discovered in practice, so I had to look it up. There was a gap in my knowledge between Pauli and the Homestake experiment:
Apparently, the original discovery of neutrinos was adjacent to a nuclear reactor; Uranium fission produces many kinds of radiation, including a broad spectrum of neutron, neutrino and gamma ray energy.
The actual detection of a neutrino absorption (extremely rare) involved not just the emission of a positron (which was detected by its characteristic gamma ray energy), but by emission of a neutron and its subsequent absorption.
Typical PET reactions emit a positron only, which then produces a pair of gamma rays with a specific energy, and opposite directions to conserve energy and momentum.
So the reaction that first detected a neutrino was a more complex reaction than the reactions used in PET scanners.
PET scanners don't try to detect neutrinos - and the energy spectrum and direction of the gamma rays shows that no neutrino is involved.
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