All Questions
Tagged with electromagnetism nuclear-physics
75
questions
2
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Coulomb potential in nuclear fission?
In the case of symmetrical fission we must consider the Coulomb potential between the two nuclei :
$$ E=k \frac{q^2}{r}= k \frac{(\frac{Ze}{2})^2}{2r_0 (\frac{a}{2})^{1/3}}= k \frac{2 ^ {1/3}}{8} \...
- 49
0
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1
answer
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How large would a nucleus have to be for the gravitational force overcome the electrical repulsion?
As a nucleus get larger, the electrical repulsion between protons grows, eventually overcoming the weak nuclear force. My question is, how large would a nucleus have to be for the gravitational ...
- 768
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3
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Could an atom have a binary nuclei system?
I can't seem to find this answer anywhere online. I am trying to work through a solid state physics textbook for research and this popped into my head. I don't have any mathematical background on ...
- 205
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2
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Why could the Yukawa potential explain how protons can be bound in the nucleus?
The Yukawa Lagrangian
$$\mathcal{L}=-\dfrac{1}{4}F_{\mu\nu}F^{\mu\nu}+\dfrac{1}{2}m^2A_\mu A^\mu-A_\mu J^\mu$$
can be used to derive the equations of motion
$$\Box A_\mu=J_\mu-m^2A_\mu$$
for the ...
- 36.4k
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NMR Concept Help
I am trying to grasp the concept of Nuclear Magnetic Resonance machines that use permanent magnets. From what I understand you use a electromagnet to align the atoms with the field, turn off the field ...
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-1
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1
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What is the difference between Strong, Weak Force and Electromagnetism? [closed]
I was watching a documentary and they said that the Strong Force is what keeps the nucleus together (Nuclear Force) and Electromagnetism is what causes the attraction between electron and nucleus so ...
3
votes
1
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How can MRI overcome diffraction limit?
MRI uses radio waves with lengths of meters.
For example, Larmor frequency for proton in the field of 1 Tesla is $42~\mathrm{MHz}$. This means $7~\mathrm{m}$ wavelength.
So how can MRI scanner see ...
- 1,732
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If the strong nuclear force is stronger than electrostatic repulsion, why don't nuclei collapse into a point?
Today in class we were discussing the strong nuclear force, and our teacher was explaining about how the strong nuclear force counteracts the repulsion force between protons in a nucleus.
When asked ...
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1
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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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What is the interrelationship among PD, T1 and T2 in relation to MRI
Proton Density (PD), Spin - Lattice Relaxation Time (T1), Spin - Spin Relaxation Time (T2) are three major characteristics by which we can distinguish different types of tissues and all three are ...
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24
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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.
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What is the relation between Nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR)? [duplicate]
It seems to me that the basic principles are exactly the same, right? Then I am puzzled that the former was awarded a nobel prize while the later not.
I noticed a similar question here What's the ...
- 1,179
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Diffusion of magnetization (NMR)
In the context of MRI I'm trying to understand the mechanisms of magnetization diffusion.
Consider a sample that is magnetized by an external magnetic field. We have displacement of magnetic moment ...
- 191
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votes
5
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Why are heavier nuclei unstable?
If you have more neutrons than protons, then there will be more strong force present to counteract the repulsive forces between protons. Why is it that above bismuth, no nucleus is stable, regardless ...
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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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