Neutrons aren’t a model of resilience when it comes to living a single life. Strip one from an atom’s nucleus and it will quickly disintegrate into an electron and a proton. But scientists can’t determine how quickly, despite decades of trying, and that’s problematic because knowing that lifetime is key to understanding the formation of the elements after the Big Bang.
Now, a team of researchers ... has provided a way that could end the decades-long stalemate. Using data from NASA’s MESSENGER spacecraft, the team shows that the lifetime of a neutron can be measured from space. ...
Since the early 1990s, scientists have disagreed about how long lone neutrons last, mainly because the two methods used so far give highly precise results that don’t line up.
The “bottle” method traps neutrons in a bottle and tracks how long they take to radioactively decay, which on average is around 14 minutes and 39 seconds. The “beam” technique instead fires a beam of neutrons and tallies the number of protons created from radioactive decay. On average, this takes about 14 minutes and 48 seconds — nine seconds longer than the bottle method.
Nine seconds isn’t much, but relative to the uncertainty in either method’s measurements — at most two seconds — it’s enormous. ...
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
Since the early 1990s, scientists have disagreed about how long lone neutrons last, mainly because the two methods used so far give highly precise results that don’t line up.
The “bottle” method traps neutrons in a bottle and tracks how long they take to radioactively decay, which on average is around 14 minutes and 39 seconds. The “beam” technique instead fires a beam of neutrons and tallies the number of protons created from radioactive decay. On average, this takes about 14 minutes and 48 seconds — nine seconds longer than the bottle method.
Nine seconds isn’t much, but relative to the uncertainty in either method’s measurements — at most two seconds — it’s enormous. ...
Might the trapped neutron rate be the true rate of decay while the fired beam neutrons are lasting slightly longer because outside observers are seeing a relativistic time dilation effect?
Bruce
Just as zero is not equal to infinity, everything coming from nothing is illogical.
BDanielMayfield wrote: ↑Sat Jun 13, 2020 2:48 pm
Might the trapped neutron rate be the true rate of decay
while the fired beam neutrons are lasting slightly longer
because outside observers are seeing a relativistic time dilation effect?
Beams of 940 MeV rest mass neutrons tend to be highly NON relativistic
[to the point where old fashioned mechanical slots
(a la Galileo) are used for velocity discrimination]:
Neutron energy Energy range
............................................
0.0–0.025 eV Cold neutrons
0.025 eV Thermal neutrons
0.025–0.4 eV Epithermal neutrons
0.4–0.5 eV Cadmium neutrons
0.5–1 eV EpiCadmium neutrons
1–10 eV Slow neutrons
10–300 eV Resonance neutrons
300 eV–1 MeV Intermediate neutrons
1–20 MeV Fast neutrons
> 20 MeV Ultrafast neutrons