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

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What is the root mean square energy?

How the root mean square energy of nucleon in a nucleous of atomic number A in ground state is depend on A ?
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Why don't the nucleus break apart? [duplicate]

The nucleus of an atom is made up of protons and neutrons. So if there are many protons inside nucleus even though there are neutrons why don't this protons may repel away breaking nucleus apart? The ...
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29 views

Which is larger, all known, bound nuclear energy levels, or known, bound atomic energy levels?

Both the atomic nucleus and the electrons are (complex) quantum systems and have large numbers of energy levels and transitions, and a basic shell model is usually part of introductory atomic physics ...
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32 views

Why are parallel spins energetically favorable for nucleons? [duplicate]

For deuterium, both the proton and neutron preferentially occupy $1s_{1/2}$ orbitals which have orbital angular momentum $l=0$ and spin $s=1/2$. By coupling their orbital and spin angular momenta for ...
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69 views

Charge structure of the neutron

David Griffiths’ book on elementary particles says that the neutron is positive at the center and edges, negative in between. (Introduction to Elementary Particles, Wiley, 1987, p. 21). But Wikipedia ...
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55 views

Basics questions about the strong force

I have what is probably a bitter misconception about the strong force which I would like to clarify. Here's my (probably flawed) reasoning. The strong forces holds protons and neutrons together at ...
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Proportion of gamma rays in radioactivity from spent nuclear fuel [on hold]

In a Pressurised Water Reactor, a certain amount of radioactive waste is produced. Over a period of many years, often decades, it decays to give off alpha, beta and gamma rays. What proportion of this ...
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At what density and conditions would Californium-251 reach a supercritical mass? [closed]

If I were to obtain a sample of Californium-251 that weighs 1mg, how would I make that sample reach a supercritical state at which it would create a cataclysmic nuclear detonation? In a sphere, at -...
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48 views

Why alpha decay usually leads to ground state while beta decay usually leads to excited state?

When alpha decay happens the daughter nucleus is usually in ground state. When beta decay happens the daughter nucleus is usually in excited state which is then de-excited by emitting gamma photon. ...
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Can the energies released during different oxygen fusion reactions be averaged?

I am conducting an investigation regarding the ideal fuel for a star of 25 solar masses In terms of how much energy is produced.I have calculated each of the binding energies involved and then ...
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44 views

Can free particle (eg. unbound electron or proton) have angular momentum other than spin?

I am learning about parity of nucleus and (elementary) particles. For example, proton has a intrinsic parity of $+1$. However, a more general term for parity of proton is $(-1)^l$ where $l$ is orbital ...
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43 views

What is the spectrum of a nuclear bomb in a vacuum?

This question about 'nukes in space' mentions that the two forms of energy released from a nuclear bomb come from neutrons and photons (the latter about 104 times the former). It's mentioned that the ...
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Why can't a nucleus become a black hole?

A nucleus is very small and very dense. Its density is approximately $2.3 \times 10^{17}~\mathrm{kg/m^3}.$ So why can't a nucleus itself become a black hole?
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What is W.u. as a unit in a nuclear physics context?

In a recent paper (doi/arXiv), of note for causing this recent tussle over its handling by science news media, there's some strange units I can't quite puzzle out. Specifically, the abstract contains ...
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Do pear-shaped nuclei really have anything to do with time travel?

Recently (in the last week or two), various articles about pear shaped nuclei have appeared, such as this one from Science Alert and this from the BBC The Science Alert article includes the quote ...
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1answer
54 views

How can alpha or beta emission maintain equal numbers of protons and electrons? [duplicate]

In radioactivity we know that a parent nucleus can disintegrate into daughter nuclei by emitting alpha or beta particles. If this is true then how can the daughter nucleus have as many electrons as ...
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77 views

Left radioactivity in Hiroshima and Nagasaki [closed]

What is the level of the left radioactivity in Hiroshima and Nagasaki? It seems that people there live very well. So, the radioactivity is very low?
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Is critical mass of fissile material the same in gravitational fields with different force?

Let's take plutonium-239 for example. $10\, Kg$ (sphere $9.9\, cm$) need for a nuclear reaction. Are we talking about these numbers in Earth environment with $\approx 9.8\, m/s^2$ gravitational ...
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46 views

Why is Helium an anomaly on the binding energy curve?

So I'm failing to understand why helium is anomalous on the binding energy curve. I know it includes concepts such as pairing, shell correction, and the liquid drop model. However, these were simply ...
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Half life and Radioactive Decay

[Sorry about the misleading title, as the query isn't entirely about half-life, but I couldn't find any better way to condense my question to make a brief enough title anyways..... and] Radioactive ...
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23 views

An approximation question from “Nuclear Models” by Judah Eisenberg and Walter Greiner

I'm looking at page 311 of the book "Nuclear Theory" by Judah Eisenberg and Walter Greiner. Now for identity (49) which is: $$\omega_{1,2}^2=\frac{\omega_\alpha^2+\omega_\zeta^2-2bc\omega_\alpha\...
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1answer
73 views

Where does the $0.61$ come from in $ R \sin \theta = 0.61\lambda $?

In my A2 Physics textbook it says that In the estimation of the nuclear radius by using electron diffraction the equation $$ R \sin \theta = 0.61\lambda $$ where: $R$ = radius of the nucleus $\...
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What causes Potassium to decay into Argon the way it does

From evolutionwiki: "Potassium 40 decays into argon 40 through a process known as electron capture. In electron capture, an electron from the innermost electron shell "falls" into the nucleus, ...
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How to calculate absorbed dosage

Lets say you have some unstable isotope which decays via beta decay. For example, lets say you want to calculate the amount of beta radiation that is emitted from the decay of $^{87}\textrm{Kr}\to ^{...
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36 views

How is the amount of radiation calculated from a decay?

Lets say you have some unstable isotope which decays via beta decay. For example, lets say you want to calculate the amount of beta radiation that is emitted from the decay of $^{87}\textrm{Kr}\to ^{...
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Nuclear physics study materials

I'm currently a ChemE undergraduate student and wish to pursue masters in nuclear engineering. Can you suggest some introductory reading material so that I can get acquainted with nuclear engineering ...
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propagation of error - sin^4

I am currently working on an analysis of a Rutherford scattering and encountered a somehow strange behaviour for the errors. It basically boils down to the behaviour of: $$\sin(\theta/2)^4$$ For ...
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41 views

C-parity violation evidence

I know about the CP-violation experiments from the 60's and the P-violation from the 50's. But, is there a similar experiment which displays (perhaps historically in the same way as the experiements ...
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57 views

Forbidden transition

My question concerns something I just read on wikipedia whilst looking up forbidden transitions, here: https://en.wikipedia.org/wiki/Forbidden_mechanism#Gamma_decay Specifically, this sentence: "...
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76 views

The counter-intuitive time scales in atomic physics and nuclear physics

Compare atomic physics and nuclear physics. The interaction in the latter is much stronger than that in the former. However, the typical spontaneous emission time scale in atomic physics is on the ...
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46 views

Derivation of Critical Mass of U-235

I am having trouble following an explanation of the critical mass of U-235 from my book (for high school physics). First off, every chain reaction of U-235 releases on average $\nu = 2.42$ neutrons. ...
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33 views

Model for obtaining the magnetic moment of a neutron [closed]

The anomalous magnetic moment of a neutron ($g_s=-3.83$) could be considered as a fixed proton ($g_s=5.58$) with an orbiting $\pi⁻$ meson in an $l=1$ state. a) What is the magnetic dipole moment of ...
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24 views

Meson production not originating from a collision

Does anyone know a process that produces mesons other than through collisions from particle accelerators and cosmic ray experiments? Thanks DaPhys
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Nuclear bomb power - myth?

I'm not experienced in physics yet (if it helps I've covered as much as acceleration, momentum and energy transfer/chemistry ionic and covalent bonding) but I've heard that the way people compare ...
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How can I determine the interaction knowing the decay formula?

I know the kind of interaction occurring in very common reaction. For example, I know that the interaction: $e^- + e^+ \longrightarrow \mu^+ + \mu^-$ is driven by the electromagnetic force (there is ...
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43 views

Can We “Tune” The Radiation Output Of a Nuclear Device.?

After reading "Project Orion", the 1950's plan to launch a large mass spaceship using small nuclear devices, (and also from common sense), I realise that a lot of nuclear research is classified. The ...
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115 views

Who determined the half-life of Uranium 235 and how?

By Wiki, the half-life of Uranium 235 is as long as 703,800,000 years. This is huge. Therefore, on an human time scale, the decay is very small. This should pose difficulty for determining the half-...
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How neutron can have an antiparticle since it have zero charge?

Antiparticles are defined as fundamental particles having the same mass but opposite charge. Now, a neutron has a particular mass (say m) , but zero charge ( =0). Its antiparticle should have mass=m ...
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Is it possible that there are stars working on fission?

Most/all stars are getting their energy from fusion of small atoms like our sun. But is it possible according to the laws of physics that there are stars getting their energy from fission fe with ...
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Effect of a nuclear weapon on the Moon

In some science fiction novel, there is the scenario of using nuclear weapons to deflect an Earth-approaching asteroid. But the question is, is a nuclear weapon really as useful on the moon or an ...
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Total Angular Momentum of Hadrons

Hadrons are made of 2 or 3 quarks. Quarks have spin 1/2, so Mesons can have spin S = 1 or spin S = 0, and Baryons can have spin S = 3/2 or spin S = 1/2. Is there orbital angular momentum of the quarks ...
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What is the BG Equation?

About 45 years ago or so I was a Physics department staff computer programmer when I was a physics major undergrad. I worked with a professor doing research on nuclear shell models -- he was ...
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What is $\beta^-n$ decay?

I'm looking on the nndc chart of nuclides and am seeing $\beta^-n$. What is this? http://www.nndc.bnl.gov/chart/reCenter.jsp?z=3&n=6
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Is the decay of nuclei also depending on the 'age' of nuclei or whether they are created or not? [duplicate]

Usually the decay is said to be randomly but the average period of decay of certain atoms are stable. So if you randomly take a bunch of the same atoms the average time before the decay will fe be 5 ...
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Assumptions that led to Wigner surmise of nuclear level spacings

In 1957, Wigner surmised (guessed) that the probability density of the spacing between adjacent energy levels of complex nuclei is given by $$ P(s) = \frac{\pi}{2}s e^{\frac{-\pi s^2}{4}} $$ This is ...
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Quantum tunneling and the Gamow Factor

I've seen the equation for the probability of particles overcoming the Coulomb Barrier in the following form: $$P(E)=\exp\left[-\sqrt{E_G/E}\right]$$ Where I'm using the numerator $E_G$ as the ...
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28 views

Gamma spectroscopy - Nuclide identification

I have a question about what the usual practice is for nuclide identification in gamma spectroscopy. For example, if I see a line at 477 keV, I would write that the origin of this line is $^7Be$. As ...
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Dependence of atomic mass number in the Bragg Kleeman rule

I have just staring learning about radioactivity, more or less about alpha particles and how there range can be approximated by the Bragg Kleeman rule, $\displaystyle{R \varpropto \frac{\sqrt{A}}{\rho}...
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Nuclear Energy Depletion in Solar System [closed]

Lets keep this simple. Lets assume that the amount of known fissionable material is fixed. Lets assume that energy demand is the same for 2015, from now until depletion, to keep it simpler. How long ...
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Gamma decay multipolar transition rate?

I have been trying to derive the equation for the transition probability per unit time/transition rate for gamma decay of a nucleus, as given by equation (21) of this article. I have also gone through ...