# Tag Info

## New answers tagged neutrons

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No, conservation of Baryon number prevents a neutron decaying into gravitons. A neutron has Baryon number $B=1$. A graviton (or any gauge boson or lepton) has $B=0$. And famously, $1\neq0$.

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This is the relative strength of interactions of elementary particles: strong 1 electromagnetic 1/137 weak 10^-6 gravity 6x10^-39 A free neutron decays through the weak interaction with a lifetime of 14.7 minutes. The gravitational interaction is 10^-33 times weaker than the weak. In the lifetime computations this would be squared .Even if baryon ...

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The neutron star crust is separated into outer and inner regions. The outer is a crust of neutron-rich nuclei surrounded by degenerate electrons. The inner is similar, but the nuclei are even more neutron-rich and there are degenerate neutrons too. The (qualitative) answer to your question looks at the ratio of electrostatic (Coulomb) energy to the thermal ...

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The transmutation of nuclear waste is a well developed research area. There was extensive work done a Dubna regarding this area. If you're looking to get into this area, there is the publication "Nuclear Methods for Transmutation of Nuclear Waste: Problems, Perspectives, Cooperative Research" published back in 1996.

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This is basically what the pressure-tube design in the CANDU reactor is. The K-infinity for a 2D CANDU bundle is (from DRAGON calculations we did in a course run by E. Nichita) about 1.12 - each one of them is critical on its own. All the bundles are surrounded by a common D2O moderator.

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Neutrino can interact only by exchange of electroweak boson. So in each reaction with neutrino $W^\pm$ or $Z$ bosons must be involved. Also, Standard Model neutrino is assumed to be massless, so there is defined handedness: neutrino is left-handed and antineutrino is right-handed. Consequence of it is that left-handed neutrino will interact only with ...

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In the reaction that you ask about the exchange boson is space-like (meaning that for that particle $E^2 - (pc)^2$ takes on a negative value. In cases like that there is no unique way to decide if you have a $W^-$ going from the nucleon to the lepton or a $W^+$ going from the lepton to the nucleon, and the drawing is usually annotated only with a $W$. ...

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If a neutron escapes from a reactor in the direction of another reactor, it can still induce fission in the other reactor, so it would not make sense to put a neutron reflector in regions between the reactors. In that sense, when considering multiple reactors put close together, the reflectors would need to be put all around them, as in the case of a single ...

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The halflife of the neutron is set by three things (more or less): the mass difference between the neutron and the proton, the number (two) of light particles that accompany the decay and the strength of the weak interaction. Changing number (3) effects the lifetime of all weak mediated processes, but all of them in the same sense. Changing (1) ...

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Ryan is correct. In addition I would point to beta decay, in one form of which a neutron is transformed into a proton, inside the nucleus. This is called $\beta^-$ decay and is accompanied by the emission of an electron $e^-$ by the affected nucleus.

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For the lifetime of the neutron to be different, the weak interaction coupling constant would be different. As far as nuclei are concerned the unstable ones with beta decays would have different lifetimes. In general all weak interaction mediated decays would have different lifetimes.

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The half life of a lone neutron is only fourteen minutes. When a lone neutron decays, it decays into a proton, electron, and electron neutrino. However, a neutron bound to a proton is relatively stable, so a neutron in an atomic nucleus would not decay.

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The application of active deconstruction schemes to manage nuclear waste has long history as a proposal, but has not yet been demonstrated as technologically practical. The usual schemes (i.e. the ones people have put time and money into and are still looking at) use electron beams (either directly or as a bremstrahlung source) because electron beams are ...

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