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

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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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151 views

Are there more photons than nuclei within the Sun?

Are there more photons than nuclei within the Sun? Is there a good way to estimate what the ratio would be?
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43 views

Can a light element with excited nucleus undergo internal conversion

Internal conversion occurs when an excited nucleus ejects a low level electron from the first 2 low energy shells such as a k shell electron instead of emitting gamma when returning to ground state. ...
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1answer
18 views

Are Fe56 or Ni56 the fission products of any binary reactions?

I'm curious as to if there is some combination of a fusion and fission event simultaneously occuring that would only produce 56 nucleon number nuclides. Such that the net energy out of the fusion ...
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2answers
108 views

Why isn't spent nuclear fuel used as a heat source? [closed]

We all know spent fuel rods taken out from a reactor core keeps generating tremendous amount of heat and needs to be kept cool by running cool water. It is also known that if cooling system fails ...
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1answer
89 views

Why do nuclear bomb explosions create an array of visible electric discharges in the form of lightening in the upper atmosphere?

I've seen videos on the internet, showing nuclear bomb test explosions, and there appears to be a large amount of visible lightening discharging numerous times over the development of the mushroom ...
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305 views

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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1answer
67 views

Difference between scattering amplitude and scattering lenght

I'm studying neutron scattering theory and I noticed that one usually writes the scattered wave as a spherical wave: $$\psi \sim \frac{-b} {r}e^{ikr}$$ where $b$ is known as scattering lenght. From ...
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3answers
44 views

About the flow of current

Generally it is said that current is due to the flow of electrons; how can we make this claim? I mean, generally we say the atom contains a nucleus which consists protons (positively charged ...
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3answers
115 views

Can there be eternal stars?

the question is quite straightforward: Can there be stars that shine forever without ever collapsing nor growing? Do we know some really, really old stars? (whatever age that might be) I hope to ...
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3answers
312 views

Does energy conservation not hold in fission and fusion processes?

I have read that during fission and fusion processes, there is some kind of equilibrium between the single nucleus and the disintegration products, so they are constantly being converted into each ...
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2answers
53 views

Are there hypothetical processes which allow the existence of a fission powered star?

I know this is impractical given the rarity of heavy fissile elements in the universe (contrary to the abundance of fusion friendly elements like hydrogen), but is there any process via which a ...
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1answer
54 views

Ground state of 113Sn from shell model

The shell model predicts that the ground state of 113Sn with 63 neutrons would have J=5/2+. But the ground state is taken to be 1/2+. What is the reason behind that? Has it got something to do with ...
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35 views

landau distribution as a model of charge deposition in silicon detector

I am would like to know if it is any explanation why the charge collected by the detector can is model by the Landau distribution. Is it any deeper explanation instead of "it is working" ? I look ...
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2answers
47 views

One Pion Exchange Potential properties for a two-nucleon system

I'm going through my Nuclear Physics book, and has come across a section called "Properties of OPEP for the two-nucleon system". It start out by considering the n-p system in a singlet spin state ...
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3answers
104 views

Why is isospin so useful?

I'm currently reading about isospin in nuclear physics, and I know how to calculate it, and all the math, but I'm actually not sure WHY it is so useful? Can anyone come with some examples where not ...
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1answer
34 views

Will ionization energy be affected by screening effect?

It would be logical to think that the more electrons are ejected from an atom, the harder it is to eject more. I just learned about photoelectric effect experiment. The book is kinda telling me the ...
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7answers
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Why is there a scarcity of lithium?

One of the major impediments to the widespread adoption of electric cars is a shortage of lithium for the batteries. I read an article a while back that says that there is simply not enough lithium ...
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1answer
108 views

Form factor for Proton

To find the charge distribution of proton , we study electron proton scattering and compute the form factor to find the cross section. The form factor comes out to be Fourier transform of charge ...
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0answers
22 views

Fermi's yield estimation of the Trinity Test [duplicate]

In Enrico Fermi's eyewitness account of the Trinity nuclear test in 1945, he gives a brief description of a method that he used to estimate the blast energy of the test: About 40 seconds after the ...
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1answer
120 views

Direct vs. Compound reactions

I know there are different types of direct reactions like inelastic scattering and such. But is the main difference between direct and compound reactions that one excites (Or at least can) the whole ...
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2answers
51 views

How to determine whether a nuclear transition would be electric octupole, or hexadecapole?

The transition from one nuclear state to another is classified as quadrupole/octupole, etc, depending on the units on angular momentum transferred. But depending on the angular momentum of the two ...
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4answers
198 views

Is a turbine the same thing as a motor?

Is a turbine the same thing as a motor? We know that water, wind and nuclear power plants rotate a turbine so is this turbine like a motor? I think we can generate electricity by rotating a motor too. ...
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1answer
1k views

Relationship between nuclear spin and nuclear magnetic moment?

We know that nuclear magnetic moment can be expressed in terms of the expected value for nuclear spin as: $$\langle\mu\rangle =[g_lj+(g_s-g_l)\langle s_z\rangle]\frac{\mu_N}{\hbar}$$ (Cf. Krane), ...
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3answers
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Nuclear fusion : ion vs atom fusion cross section?

I've read critique on ITER project (in Russian), and one of points was that cross section of ion-ion fusion is much lower than ion-atom and atom-atom, and that's the reason why it likely to not work. ...
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3answers
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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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5answers
1k views

Why do almost all nuclear reactions release energy?

I'm just wondering why almost all nuclear reactions release energy, in a typical way, the mass defect is transformed into energy ? Is there a nuclear reaction that gains mass (resp. energy)? or most ...
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1answer
90 views

Lead - Lithium = Gold?

In reference to this question about transmuting lead into gold, I'm looking for a correct, though magical, way to turn lead into gold. I'm not worried if it's possible to split off a lithium nucleus ...
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13 views

Where to get the AME2012 isotope mass table?

what's the official site for getting the latest isotope mass table, i.e., AME2012? All links I have found (NIST, IAEA) point me to a site at the Chinese Academy of Sciences, but the link ...
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2answers
147 views

Advanced Molten Salt Reactor - Is the concept of designing a reactor that uses spent nuclear fuel to generate power technically feasible?

I was going through the concept of designing a Nuclear Reactor that uses Spent Nuclear Fuel(SNF) to generate power as proposed by Transatomic Power . ...
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1answer
158 views

From which height the effect of nuclear bomb will be Greater?

Well I was wondering like during war some of them drop nuclear bomb on ground and then it explode and we see a huge blast which causes so much of destruction but my question is that is it possible ...
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2answers
3k views

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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202 views

In the Iranian nuclear deal, how can IAEA detect nuclear activity after 24 days?

This is a question related to current events, but I want to ask about the physics, which are not explained in any news article that I can find. Ernest Moniz and John Kerry wrote an op-ed in the ...
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2answers
1k views

How close are humans to creating gold from other elements?

Gold is made in supernovae. How close are humans to doing that? Or is it even possible to do that unless gravity is absurdly high?
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1answer
164 views

Can Antimatter undergo nuclear fission/fusion?

I was curious if antimatter could undergo nuclear fission/fusion with other antimatter. It makes sense, I was wondering if it would work?
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1answer
160 views

When does electron capture occur and when does positron emission occur?

I’ve been told that electron capture occurs when there isn’t enough energy to produce a positron by beta plus decay. Exactly why is this the case? Why does it take more energy for positron emission ...
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2answers
178 views

Pentaquark spin prediction

Is there a straightforward way to see what the spin of the recently-discovered pentaquark states should be, from the representation theory of $SU(3)\times SU(2)\subset SU(6)$? I can see that from the ...
4
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1answer
53 views

Can an electron in an atom have insufficient energy to achieve an energy level, or orbital, and what happens to this electron when this occurs?

If a nucleus undergoes a change in Z or Mass due decay or absorption, could this disrupt the electrons from their orbital/shell energy levels? If so, could the electrons that were previously in the ...
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1answer
27 views

Is there a directional aspect to Beta decay dependant on nucleus orientation

Does beta decay occur in certain directions relative to a nucleus orientation? Would the nucleus geometry or spin direction have an impact? This effect could may be tested if a radioactive nucleus ...
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0answers
26 views

Effect of nucleus geometry and states on the Coulomb barrier and the electric potential well surrounding the nucleus

In some models of the nucleus it has a geometric aspect due to the combination and alignments of the charges, magnetic moments and spins of the protons and neutrons it contains. Even in models that ...
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2answers
1k views

When did the first carbon nucleus in the Universe come into existence?

I am a chemist with a passion for astrophysics and particle physics, and one of the most marvellous things I have learned in my life is the process of stellar nucleosynthesis. It saddens me how my ...
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1answer
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Binding energy and mass

I’ve been told that a greater binding energy means the nucleus is more tightly bound, and therefore that decreases the mass of the nucleus with respect to its nucleons when separated. But why does a ...
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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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2answers
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Why does the Walecka model not include pions?

The Walecka or $\sigma$/$\omega$-model is an effective theory describing nucleon-nucleon interaction by an exchange of $\sigma$/$\omega$-mesons. Why does it not include interactions by pions?
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3answers
369 views

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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2answers
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Effect on electron shells energy levels during nuclear decay

First thanks for this great site. I was recently looking at photon emission from electron transitions from excited electron states in atoms. For simplicity I was using the Rutherford Bohr Model and ...
2
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1answer
115 views

Using particle accelerators for nuclear fusion [duplicate]

Apologies this is probably a stupid idea but I am curious and my knowledge of physics is limited as I am 14. So I was wondering if we could use particle accelerators to achieve nuclear fusion. I have ...
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2answers
142 views

Textbook for learning nuclear physics

I've taken a college level course on nuclear physics. Though the course was titled "Nuclear and Particle Physics," almost nothing about elementary particles had been taught. I'm on vacation now, and ...
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1answer
980 views

Theoretical power limit of nuclear bomb

Is there any limits of power or power to mass (or any other) limits for nuclear bombs? I found this wiki article: Nuclear weapon yield: Yield limits. Is the information provided is correct? If yes, ...
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1answer
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Reaction of uranium and neutrons emits neutrons, or is it photons?

So we had this test in nuclears physics today, and part of one of the quesitons was the following: When $\rm U^{235}_{92}$ nuclides are bombarded with one neutron, they can decompose to krypton ...