Nuclear physics is the study of the composition, behavior and interaction of atomic nuclei and their constituent parts.

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Does quark color contribute to “spin degeneracy” for QGP calculations?

Like the title say, does quark color matter in counting contributions in a early universe plasma (QGP), as when adding up the total plasma energy density, or is it just spin? The book I have (Pathria) ...
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Are atoms made of protons, electrons and neutrinos?

If neutrons decay into proton, electron and (anti)neutrino of electron type, then is it safe to say that atoms are protons, electrons and neutrinos?
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Is it possible to obtain gold through nuclear decay?

Is there a series of transmutations through nuclear decay that will result in the stable gold isotope ${}^{197}\mathrm{Au}$ ? How long will the process take?
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“Dear radioactive ladies and gentlemen” - Letter by Wolfgang Pauli

In 1930, Wolfgang Pauli wrote a letter to Lise Meitner for a convention in Tübingen, considering the problem of beta decay. Does anybody know, where to find the original letter online ?
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Where does the energy from a nuclear bomb come from?

I'll break this down to two related questions: With a fission bomb, Uranium or Plutonium atoms are split by a high energy neutron, thus releasing energy (and more neutrons). Where does the energy ...
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616 views

About mass defect

Here's how my book explains mass defect: Particles inside the nucleus interact with each other - they feel attraction. The potential energy $U$ of such attraction is negative, because in absence ...
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Does the “Energy Catalyzer” by Andrea Rossi et al. generate energy by converting Nickel to Copper?

From Wikipedia: The Energy Catalyzer is an apparatus built by [...] Andrea Rossi, [and] Sergio Focardi. The 2009 patent application claims "a method and apparatus for carrying out nickel and ...
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Tunneling of alpha particles

Consider this explanation of the alpha decay: It says The Coulomb barrier faced by an alpha particle with this energy is about 26 MeV, so by classical physics it cannot escape at all. ...
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Is a Plutonium gun-type atomic bomb really “impossible”?

I caught a pretty well done 2 hour documentary on atomic bomb history yesterday on the local PBS station. In it, they go over the paths taken for design of the first bombs, including the Thin Man ...
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Can Dark Matter just be clumps of Neutrons

I was wondering about Dark matter, and it occurred to me that why could it not be just nuclei of Neutrons with no electron cloud. Is it possible for such things to exists. Can Neutrons bond to one ...
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102 views

Why is a stellarator-type nuclear fusion reactor so oddly-shaped?

My first impression: It's a mess. Why is it shaped like that? I can't find any info about its shape other than it's a special arrangement of magnetic coils. (link) Here's some more images of it on ...
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Why is Helium-3 better than Deuterium

I see that many websites and magazines with physics thematic are pretty excited about mining Helium 3 isotope on the Moon. But this seems to be a very hard-to-get resource. For more than one reason: ...
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Nuclear fuel pellets - when does the chain reaction start?

Questions about nuclear fuel: Does nuclear chain reaction start in fuel pellets even before they being installed in reactor? If not, why not? My understanding is that since the fuel pellets are ...
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Mass defect- From where mass is being lost?

As a school student, I have wondered while studying mass defect the following mysterious problem My assumption Just like a car's mass is constituted by each part of it(i.e total mass of car will be ...
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198 views

Radioactive nuclear fuel?

I suppose this is a not-too-bright question but, in a nutshell: why are nuclear fuels radioactive? With this I mean, which is the connection between being a fissile (or fertile, for that matter) ...
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277 views

Why a slow moving neutron is required in nuclear plants?

I came across a line that said "an atom of heavy element is hit with a low velocity neutron, otherwise the required reaction would not achieve result". So, why not a neutron of high velocity is ...
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597 views

What is the percentage of useful energy do we get from matter-antimatter annihilation?

This is a theoretical question since we haven't made enough antimatter to try it in reality of course. But I am asking about the physics part in this. Also, by "useful energy" I mean the energy we ...
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Radioactive Decay

Problem:Nuclei of a radioactive element $\Bbb X$ having decay constant $\lambda$ , ( decays into another stable nuclei $\Bbb Y$ ) is being produced by some external process at a constant rate ...
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How do alpha and beta particles ionise surrounding particles?

I've been wondering about this question for a while. If you have alpha and beta particles released from a radioactive core, how do they ionise surrounding particles?
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How do scientists measure the spin-parity of a resonance?

I have seen many plots and data tables which display the cross-section vs. center of mass energy for a particular nuclear reaction at a given angle. Here is an example. You can see that there are a ...
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196 views

Importance of MHV amplitudes

Why are MHV amplitudes so important? How/where are they used and why do people keep trying to rederive them in many different ways?
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Why doesn't the deuterium nucleus have spin 0?

A deuterium nucleus is composed of a proton and a neutron. Both have spin 1/2 so I would expect the deuterium to have two possible spins: 1 for the triplet and 0 for the singlet. But apparently ...
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70 views

Incoherent assumption of the parton model

Consider the scattering process $ep\rightarrow eX$, in the frame of an ultra-relativistic electron, the partons inside the proton are "frozen," and since the time scale of strong interaction is much ...
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210 views

What is the the Ehrenfest-Oppenheimer rule on the statistics of composite systems?

Ehrenfest 1931 gives an argument to the effect that the application of the spin-statistics theorem to composite systems is valid, but only as an approximation and under certain conditions. ...
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What is the most stable nuclide of an isobar?

From the semi-empirical mass formula, the mass of an atomic nucleus is $$M\left(A,Z\right)=Zm_p+(A-Z)m_n-\frac{E_b(A,Z)}{c^2}$$ I've been told (at first) that for a given mass number $A$, the most ...
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Nuclear/quantum physics simulation software

Is there any software which is able to simulate D-T interaction for example and get temperature-crosssection curve without referencing to any experimental data? Do we have quantum-level simulation ...
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Is there any reproducible tested evidence for Ni-H cold fusion?

The main replications of cold fusion, the ones that are beyond reproach, used Pd/d as the system. But commercial developers have often claim to use Ni-H to achieve similar effects. The claims include ...
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How can the nucleus of an atom be in an excited state?

An example of the nucleus of an atom being in an excited state is the Hoyle State, which was a theory devised by the Astronomer Fred Hoyle to help describe the vast quantities of carbon-12 present in ...
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Why does an atom remain uncharged after emission of an alpha particle?

When an alpha particle is emitted, two protons and two neutrons leave the nucleus but the electrons remain the same in number. Why does the atom remain uncharged although it appears it should have a ...
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792 views

Reason why stars do not produce elements heavier than iron

In his book "Origins", Neil deGrasse Tyson says that "if you seek to split iron nuclei apart, you must them with additional energy. On the other hand, if you combine iron atoms they will also absorb ...
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272 views

We're all star dust?

OK so we've all heard of this from Carl Sagan, Lawrence Krauss and others and we know the argumentation, I don't refute that. There are other examples, for instance I once calculated (this was before ...
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Do some half-lives change over time?

I was recently doing some physics tuition on radioactivity and the student claimed her chemistry teacher had said that radioactive substances can be grouped into two divisions: those whose half-life ...
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Where do electrons get their ever-lasting circulating energy?

We all know (or maybe know) that to move, we need to spend energy. If you want to drive a car, you gotta spend gasoline. We also know that energy can't be created (first law of thermodynamics, and ...
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Nomenclature of hadronic resonances

I have the Particles Physics Booklet and I noticed that the resonances that decay into a nucleon and pion are indicated by an abbreviation. For example $P_{33}$ is associated to the $\Delta (1232)$ ...
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What causes radioactivity? Is it a quantum mechanical effect?

I'm just curious what causes radioactivity. I've been told that in the case of alpha decay, since the nucleus is quantum mechanical, there is a probability that the configuration of protons and ...
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Could we prove that neutrinos have mass by measuring their gravitational signature?

It is now said that neutrinos have mass. If an object has mass then it also emits a gravitational field. I appreciate the neutrinos mass is predicted to be small, but as there are so many produced ...
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Would being underwater help survive a nuclear bomb?

If I jump in my pool, on the river near my house knowing that a nuclear bomb, or atomic or H-Bomb exploded around 10 km from my house, would I survive? The way I see it is that water will protect me ...
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Do brick walls effectively protect against ionizing radiation from a nuclear explosion?

Of course it depends on the distance and the amount of radiation, so let's say its about 10,000 Rad. Now, can wall made of brick protect someone behind it from such radiation ?
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Radioactive decay - What mechanism decides when an unstable nucleus decays?

My first question on Stackexchange (if it is formatted wrong or something please tell me so I know in future) - here it is: Given an unstable nucleus (exactly which nucleus is not particularly ...
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Why doesn't a nuclear fuel pool become irradiated?

Why doesn't the volume of water in a nuclear fuel pool become irradiated? Why wouldn't the water around the pool become radioactive and circulate around making the whole thing deadly? My question ...
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Xray compression of secondary in hydrogen bomb

Accounts of the "secret" of the hydrogen bomb describe Xrays from a primary fission explosion reflecting off of the bomb case (occasionally passing through polystyrene foam) and compressing and ...
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How to explain $E=mc^2$ mass defect in fission/fusion

What is the nature of nuclear energy? This is closely related to the correct explanation of mass defect. I did some research of that topic and cannot come to a single comprehensive and consistent ...
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Effect of temperature on radioactivity?

I'm researching the effect of temperature on uranium radioactivity, however I can't find any solid empirical evidence to prove the notion that temperature does not affect radioactivity. Can anyone ...
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How is it possible to calculate the energy liberated by a given fission process?

How is it possible to calculate the energy liberated by a given fission process? For example, in the fission of a $^{235}$U induced by capturing a neutron?
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Why would two protons repel?

I understand that two protons would repel due to them both being positively charged, however, wouldn't the strong force act on the two protons pulling them together? Would this mean that in this case ...
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Does the Strong Nuclear Force follow Superposition?

I have just started the study of nuclear physics in my high school, and while reading about nuclear forces and binding energy per nucleon, I found out that the nuclear forces are highly short ranged ...
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Is there still mystery about spin crisis?

The gluon is a vector boson; like the photon, it has a spin of 1. If this is true and if we know the spin of protons and neutrons then why the news SPIN COMES FROM GLUONS? is telling that, we ...
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227 views

Energy balance for beta decay of cobalt-60

I am confused by a simple fact about the $\beta^{-}$ decay of ${}^{60}{\rm Co}$ nucleus. According to Wikipedia, the most likely decay branch is to an excited state of ${}^{60}{\rm Ni}$, see the ...
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If quarks didn't have mass, could protons (and neutrons) exist?

I read here (mass of a proton) that the mass of a proton is mostly (99%) due to the energy of the strong nuclear force which binds the quarks together, and not the actual mass of the quarks. My ...
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Matter-antimatter annihilation

What happens if different size atoms meet? We've just created anti-helium, I think. What if one atom of anti-helium collided with one atom of iron. Would some of the iron be left over as a new ...