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

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only one material (meta)stable at extreme pressures?

Is the pressure at the center of a neutron star so high that everything is crushed into neutronium, no matter what the original elements were? What is the highest pressure (at low/moderate ...
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524 views

Deriving Gamow factor for potential with effective centrifugal potential term

I am looking at deriving an expression for the Gamow factor for $\alpha$-decay. I understand that the potential is the sum of the nuclear, electric and effective potentials: $$V(r) = V_N(r)+V_c(r) ...
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42 views

Why does a spinning nucleon generate a magnetic field?

I am trying to understand how NMR works, but I am not sure why a spinning nucleon produces a magnetic field. Is this a consequence of the quark structure inside?
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Could we make things out of newly discovered particles?

Right now, all of the "stuff" that has been created in the world is made of protons, electrons, and neutrons. I'm aware that particles other than these have much shorter lifetimes. But I've also heard ...
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150 views

Electron scattering to measure the nuclear radius

I have been taught that you can find out the size of a nucleus of an atom by firing electrons at high velocities at the atom. This causing scattering due the positive charge of the nucleus and ...
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981 views

What is the strong nuclear force between proton and neutron in deuteron?

The nucleus of deuterium, called a deuteron, contains one proton and one neutron. What is strong nuclear force between them?
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136 views

Mass Defect…cause and origin?

What makes it occur? How do the protons and nucleus know that they have to lose mass to produce energy...? And is the mass of a compressed Spring more than an uncompressed one?? does a body which has ...
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2answers
235 views

Do all isotopes have a half life? [duplicate]

I understand that some isotopes of an element have a shorter half life, and decay more quickly into other elements. Other isotopes are described as stable and no half life is stated. For elements that ...
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263 views

The original thorium reactor?

With lunar thorium being common, and heavier than iron or nickel, does earth's core have the the occasional nuclear reaction?
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185 views

Charge on the remaining atom after Alpha decay

In radioactive alpha decay, a helium atom is shown to be released. However, I was told that only thing released is a helium nucleus. If so, then it should leave two of its electrons in the atom ...
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63 views

Could someone explain the “revolving frame” to me, as it is used in basic NMR?

I am an undergrad intern at a national lab currently working with a basic proton NMR device. The device consists of two big coils which provide the static magnetic field, and a smaller coil, which ...
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33 views

Energy needed for exoergic nuclear reaction

To initiate endoergic nuclear reaction (negative Q Value)minimum energy is supplied which is slightly more than Q value. Then what will be the energy needed for intiating exoergic nuclear reaction ...
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References or resource recommendation for the mathematics concerning fission

I am working on a statistical problem that appears similar (in some respects...) to nuclear fission. I am interested in the properties of a system undergoing fission around, or near, delayed ...
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32 views

Gain of entropy

Can we really interpretate third thermodynamic law as unconditional gain of entropy of closed system? For example, when they separate U 235, they drive the mix on the pressure barrier, so heavier U ...
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159 views

How to calculate scalar neutron flux

I am really confused about the difference between flux and scalar flux. I have a specific question: If we have a parallel neutron beam of strength $\phi_0$ given in neutrons/cm$^2$s, incident on a ...
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22 views

Relativistic non-linear Walecka model

What is meant by a relativistic non-linear Walecka model? What are some various sources to study it? [And why cannot Google show a satisfactory result to such a simple question?]
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3k views

Can open, unsafe nuclear fusion reaction burn the atmosphere?

I happened to hear people saying that the nuclear fusion bomb tests could set the atmosphere on fire. I have some serious doubts about that - but I have no facts. Nuclear fusion reaction requires ...
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157 views

How much pressure would be needed to contain a 1 gigaton nuclear bomb explosion within a sphere of one meter radius?

How much pressure would be needed to contain the largest human exploitable nuclear bomb within a sphere of one radius? Also would it be possible to create a magnetic field that controlled some ...
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51 views

Why is there not much research into nuclear physics with plasmas?

There is a lot of research and theory around fusion reactions with plasma, but is there a reason why plasmas cannot be used for researching other nuclear reactions, either in the lab or from ...
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82 views

Effect of pressure increase on electron orbital wave functions

One of my nuclear physics exercises was to find out if increasing the pressure of a sample of $^{7}\textrm{Be}$ would increase the chance of electron capture to $^{7}\textrm{Li}$ occur. My reasoning ...
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45 views

Why spin-$\frac{1}{2}$ nuclei have zero electric quadrupole moment?

Why spin-$\frac{1}{2}$ nuclei have zero electric quadrupole moment? How to calculate in general?
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230 views

Theoretical Stability of “AB-matter”

Alexander Bolonkin has proposed the possibility of manipulating nucleons to produce stable, macroscopic structures of nuclear matter at zero pressure (which he calls "AB-matter"), by analogy with the ...
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69 views

diffrent elements from diffrent elements [closed]

Do we get elements from other elements ? Somebody said they believed the world was visited by aliens and they made slavs of us and then amde us mine gold for them then they leave us to grow into what ...
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1answer
71 views

Would it be possible to “recycle” nuclear warheads into nuclear energy? [closed]

The number of nuclear warheads in the world is estimated (!) to be over 16,000. [0] Surely, this stockpile represents a massive threat to humanity. My question is simple. Can we repurpose these ...
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631 views

If there is a meltdown at the Fukushima reactors, would the control rods melt also?

According to the reports, the shutdown procedures at all the Fukushima reactors were successful, and all the control rods were fully inserted. So - if there was a meltdown, would the control rods ...
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35 views

Rotational wave funtion of a nucleus

The rotational hamiltonian of an axially symmetric rotor is, in the intrinsic frame of the body, where the moment of inertia is diagonal, $$\mathcal{H} = \frac{\hslash^2}{2I} \left(J^2 - I_3^2\right) ...
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31 views

Where can I find a list of approximate excitation energies?

I would like to know the excitation energies for the known states of various nuclides. Is there a list somewhere that has this documented? I can't seem to find them easily for many nuclides. Maybe I ...
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982 views

What happens to Protons and Electrons when a Neutron star forms?

What happens to Protons and Electrons when a Neutron star forms? At some point gravity overcomes the Pauli Exclusion Principle ( I assume) and they are all forced together. What happens in the ...
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2answers
314 views

What makes a nucleus unstable?

My question is simply that - what makes a nucleus unstable? What exactly causes a nucleus to start breaking apart in the first place? Is it the Coulomb force between the neighboring protons? I'm just ...
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29 views

Why does U-235 split into barium and krypton in nuclear reactors? [duplicate]

For my chemistry project I have found the typical fission reaction which occurs in nuclear power plants is when nuclear fuel rods are bombarded with neutrons, splitting U-235 into isotopes barium and ...
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1k views

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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49 views

Why do NNLC and NIST appear to give different values for the mass energy of the deuteron?

There is a problem with data that I've obtained over the internet. Here are the two sources of information from which I'm retrieving my data. NNLC and NIST On NIST, I have read that the mass excess ...
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45 views

Why is 0 $\nu \beta\beta$ decay often written with electron emission and not positron?

According to http://www.cobra-experiment.org/double_beta_decay/ I can see that double $\beta$+ decay is possible, but I often find neutrinoless double beta sources with the double $\beta$- decay ...
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3answers
106 views

Do electrons get accelerated or decelerated by the atoms of the anode during X-rays production?

The electrons striking the anode get deflected by the heavy nucleus. Though the speed may or may not change, the direction of motion changes which leads to acceleration. The charged particles emit ...
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Does a lack of windows protect against shockwave of a nuclear attack?

I know that one of the dangers of a nuclear attack is the shockwave which compresses the air and can cause a pulmonary embolism in creatures in the area of effect. Is the shockwave directional in ...
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Age of the Earth and the star that preceded the Sun

One of the great unheralded advances made in the history of science was the ability to determine the age of Earth based on the decay of isotopic uranium. Based on the apparent abundance of uranium in ...
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Why did “tickling the dragons tail” by Louis Slotin not cause an explosion?

I have been reading the excellent Command and Control by Eric Schlosser and discovered more about Louis Slotin's experiment with "tickling the dragons tail" and the infamous Demon Core. What I don't ...
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29 views

The Form Factor in Nuclear physics

We know $$F(\vec{q})=\int e^{i\vec{q}.\vec{r}} \rho(r^\prime) dv^\prime$$ where $\vec{q}$ is the momentum change of scattering electron. But what is the physical meaning of it ?!
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59 views

Identification of massless, chargeless $x$ in a nuclear reaction

On Friday, we had our Physics test. We (the tenth grade students) have the basic introduction to Radioactivity and a few nuclear reactions in our syllabus. In the test, the following question was ...
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99 views

How do scientists estimate elemental-abundance in the universe?

I understand how cosmological observations can estimate the amount of 'baryonic matter' in the universe, but what I don't understand is how scientists can estimate the abundance of a particular ...
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227 views

What does the exponential decay constant depend on?

We know the law of radioactivity: $$N=N_0e^{-\lambda t}$$ where $\lambda$ is the exponential decay constant. My question is: This constant depends of what?
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Ambiguity in ordering of isospin states for Clebsch-Gordan coefficients

In studying isospin for nuclear physics, I am confused a bit by an ambiguity I found. If a process that goes from $K^- + p \rightarrow \Sigma^0+ \pi^0$, I can write the isospin for the left hand side ...
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140 views

Isospin quantum number for light nuclei

Does anyone know where I can find the Isospin values for light nuclei (H, C,N, O, S, Cl, ..) in their ground state?
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41 views

$\beta^+$ decay question

I read that all baryons apart from the proton itself decay into protons (why though?) and that mesons do not decay into protons due to having less mass than protons. Thus it makes sense for the ...
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2answers
39 views

Detecting radioactive material at a distance

I have heard a lot about the failures of even the best-funded anti-ballistic missile technology. The usual explanation is that ABM is very hard after the boost phase because of evasion techniques and ...
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1answer
43 views

Is chain reaction possible in stable isotopes?

Is nuclear chain reaction possible in isotope that is considered stable? Are there examples?
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46 views

How doesn't an ionization chamber leak?

I'm sure my understanding of an ionization chamber is incorrect, so please point out the error. Suppose we are using an sealed ionization chamber to detect the energies (trajectories) of a particular ...
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102 views

Starting a nuclear reaction

In Chemistry, an amount of energy has to be supplied for a reaction to occur. This energy, known as the "activation energy", breaks up the bonds between molecues in the substance. It is equivalent to ...
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1answer
42 views

Alpha decay radioactivity [closed]

Do electrons actually escape from a radioactive element ? Or simply the helium nuclei that ? what actually is the structure of a fully decayed radioactive element ?
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77 views

Chemical potential for nucleons

Do you know if the concept of chemical potential can be properly defined for nucleons in the nuclei? I mean, if I can picture the nuclei like an interacting gas of nucleons, then may I think of a ...