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

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On the theoretical aspects of the development of the first nuclear bombs

I've just read that 68 years ago Little Boy was dropped on Hiroshima, which made me wonder about some rather historical facts about the development of the first nuclear bombs; they seem to be several ...
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30 views

Nuclear Fission and Fusion [duplicate]

I've read several other answers on here, but I still don't understand. Why do both fission and fusion release energy? I know the masses drop, but then why do the masses drop on both? Fusion is taking ...
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62 views

Why do Nuclei lose mass?

When it comes to things like gravity and the electromagnetic force, masses aren't reduced-but with nuclei the mass difference is noticeable. What about nuclear forces makes them capable of putting ...
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118 views

Why nuclear tests move under ground since 1964?

According to this database: http://www.ga.gov.au/oracle/nuclear-explosion.jsp Since 1962, 99% of USA Nuclear tests was underground. Since 1964, 99% of Soviet Nuclear tests was underground. Is it ...
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1k views

In nuclear fusion reaction, what is the percentage of mass converted to energy?

I read somewhere that it is about one percent of the mass, but I find this too high. Also I have done some calculations, for example, the Tsar Bomba was 50 MT bomb and weighed about 27 tons. Although ...
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1answer
60 views

Reaction of Pu-239 to gradual increase of pressure

The question "Did NASA nuke Jupiter?" while debunked immediately (non-fissile isotope was used) arose many what-if questions. What would happen if a subcritical chunk of a fissile isotope, like ...
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1answer
64 views

Transmutation with cosmic radiation possible?

Can cosmic radiation (alpha radiation) transmute the material of a space craft, particular carbon, titanium and aluminum? Where can i find transmutation tables or formulas to calculate the ...
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84 views

nuclear physics- Energetics and Mechanics of Nuclear Reaction Homework

A sample of $^{24}_{12}\mathrm{Mg}$ is bombarded by a monoenergetic proton. If the resulting nucleus in a $^{24}_{12}\mathrm{Mg}(p,\gamma)$ reaction; $^{24}_{12}\mathrm{Mg}(p,\gamma)$ has its ...
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176 views

Drop a star in a river [closed]

I (as I am sure you will be able to tell) know very little about nuclear physics, so please understand if something here seems dumb or obvious. I am going to question some Hollywood physics here. At ...
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126 views

Neutron decay and particles

On this picture you can see that this $d$ quark turns into $u$ quark and makes this $W^-$ boson. $W^-$ then apparently turns the anti-electron neutrino, $\bar{\nu_e}$, into an electron, $e^-$. My ...
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1answer
89 views

Nillson Potential [closed]

We define a Hamiltonian to derive Nilsson potential, $$\hat{H}=-\frac{\mathbf{\hat{p}}^2}{2m}+ \frac{1}{2}m\left[\omega_\bot^2(\hat{x}^2+\hat{y}^2)+\omega_z^2\hat{z}^2\right]$$ Nilsson model is a ...
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1answer
267 views

Coordinate system

Quoting from 'Nuclear Physics - Theory and Experiment' by RR Roy, BP Nigam 2005 edition Link to text How did the author arrive at equations (23a, 23b,23c)? Chapter 8 Nuclear model II, 8.7 ...
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69 views

Energy in nuclear reactions

I have two questions, been trying to get definite and intuitive answers to them for some time so hopefully you can help me: 1) I understand both the strong force and binding energy but what is the ...
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1answer
94 views

What is the minimum density required for nuclear fission?

This is a followup to a prior question I asked about gaseous nuclear fission. What is the lowest nuclear fuel density required to initiate fission? This is critical for a gas core reactor with a ...
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1answer
121 views

Rotational Hamiltonian for collective model

The effect of rotation can be considered by modelling the nucleus as a rotating body, characterised by some moment of inertia. Then how The Hamiltonian describing rotation is? ...
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0answers
72 views

Symmetry for even even nuclei

For even even axially symmetric nuclei K=0 because even even spherical nuclei don't show rotaional spectra and therefore do not rotate about the axis of symmetry; Thus the angular momentum about a ...
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168 views

Hamiltonian Nuclear collective model

Let $\mathscr{I}_3$ and $\mathscr{I}$ are the moments of inertia for rotations about symmetry axis 3 and about an axis perpendicular to it , and I is the angular momentum operator with components ...
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1answer
39 views

How does one define “Nuclear Harmonicity”?

How does one define Nuclear Harmonicity? Although the title is pretty much the entire case, the main question is, what exactly is "harmonicity" in terms of nuclear physics? What does it mean for a ...
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391 views

An atomic bomb explodes inside of an “unbreakable” container which is on a scale. Does the “weight” of the container change?

This may or may not be an incredibly stupid thought experiment, but a short time ago I read that most of the "mass" in the proton was actually energy from the quarks and gluons, as opposed to the ...
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2answers
384 views

Does the Nuclear reaction happen inside the fuel rods?

I've been reading up on nuclear reactors, and understand explanations of how it works, how water is heated to steam, which turns the turbines, etc.. I understand all of the safety features, and how ...
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45 views

Difference between $K_{\alpha}$, $K_{\beta}$ and binding energies

I'm having a small question regarding $K_{\alpha}$ and $K_{\beta}$ emissions. If I'm not mistaken this happens when there is a transition from the L shell to the K shell (Depending on the orbital), ...
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2answers
1k views

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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1answer
163 views

Are multipole fields, multipole expansion, and multipole radiation the same thing?

Interaction between electromagnetic radiation and nuclei can be written in terms of multipole radiation. Are multipole fields, multipole expansion and multipole radiation the same thing? I have found ...
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2answers
640 views

Total Angular Momentum of deuteron

I'm studying for my nuclear physics exam and the book we use is Introductory Nuclear Physics by K.S. Krane. In the chapter on Basic Nuclear Structure, we research the deuteron. However, when ...
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2answers
701 views

Under what conditions is a pure fusion nuclear bomb possible?

Is it possible to build a pure fusion and powerful nuclear bomb? (because due to the harsh conditions of enriched uranium, I would guess most of today's world countries will want to build pure fusion ...
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417 views

Why does it take so long to make a nuclear bomb?

So as I know nuclear bombs are derived from fission reactions: By providing the nucleus with enough power to trigger a chain reaction. If uranium was present why does it take so much to make a nuclear ...
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378 views

Nuclear Binding energy

The nuclear binding energy, is the energy that is needed to seperate the nucleons in a nucleus. And binding energy is also defined as the energy given out when a nucleus forms from nucleons. Also ...
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1answer
175 views

Fusion vs. Fission

I understand why fission generates large amounts of energy when the nucleus is split, but then why does fusion generate such large amounts of energy. If fission releases energy when some mass is lost ...
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1answer
144 views

Gaseous fission: Has it even been demonstrated experimentally?

I've been reading quite a bit about gas-core reactors, a theoretical reactor design where the fissioning of Uranium(along with Plutonium & possibly Thorium)occurs in gas phase. The result is that ...
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How do you build a nuclear reactor in your garage?

When I came across this link earlier today, I was astounded. Nuclear reactors are immensely complex devices that took scientists years to develop, and are usually housed in huge facilities. The link ...
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112 views

Theoretic Mass Energy Conversion?

say you had a large quantity of a heavy element such as uranium... AND you put a massive amount of energy into it, so that it began to undergo nuclear fission and transformed to a significantly ...
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1answer
228 views

What has $E = mc^2$ to do with nuclear powerplants?

In life, when you talk about nuclear energy, there always happens to be a guy who says that famous Einstein's equation. "Yeah, they just convert mass to energy, $E = mc^2$ ya know?" When I think ...
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1answer
344 views

Proton mass and Weizsäcker's formula

I'm so confused in the use of nuclear masses and atomic masses. I have two questions. From the book "Outline of Modern Physics" by Ronald, I understand that the semiempirical mass formula ...
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1answer
113 views

One body harmonic oscillator states expressed in terms of creation operators

I am reading trough chapter one of Moshinsky's "The harmonic Oscillator in Modern Physics". However i am having some trouble with the mathematics in section 8 of chapter 1. I will sketch a summary of ...
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2k 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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152 views

What's gonna happen if a nuclear bomb explodes nearby? [closed]

I live in the capital, 10 km from its center on the 9th floor, my windows facing the opposite direction will I still see a flash? Will I hear something? How loud will it be? How fast would I die? If I ...
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777 views

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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2answers
108 views

Harmlessness of a pure alpha decay particle

From my high school physics class I remember that there are some particles which exhibit pure alpha decay (i.e. alpha decay to there stable isotope), like Po-210, Po-211 and Bi-209. What I also know ...
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174 views

$Q$-value in nuclear reaction $^{9}Be\left(\gamma,n\right)^{8}Be$

I have two questions. First, I understand that in a nuclear reaction $$Q:=K_{after}-K_{before}\equiv E_{0,before}-E_{0,after} \qquad (1)$$ where $K$ is the total kinetic energy, and $E_0$ is the ...
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1answer
67 views

Calculate energy from an reaction [closed]

I'm trying to calculate the released energy from a reaction. The radioactive substance polonium decays according to this formula: $$^{210}_{84}\mbox{Po} \rightarrow \mbox{X}+^4_{2}\mbox{He} $$ At ...
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2answers
468 views

Stable Nuclei - Deviation from equal protons and neutrons

While studying the semi-empirical mass formula for nuclei, I came across an "asymmetry term" whose function, as far as I understand, is to build in the fact that nuclei "prefer" to have equal numbers ...
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266 views

Electric potential energy after nuclear fission

We have a uranium-236 nucleus that fissions into two equal fragments, and I'm supposed to find the electrical potential energy just as the two fragments split apart. No other information is provided. ...
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1answer
114 views

Uncertainty Principle on System of particles

I am new to Quantum Mechanics. I read the uncertainty principle - it says there are pairs of physical quantities which can't both be determined with certainty for a particle. My question is does the ...
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1answer
342 views

what is the magnetic quadrupole operator?

To find magnetic or electrical moments in quantum theory we must calculate the expectation value of an appropriate operator. the dipoles operator are similar and is easy to find but the magnetic ...
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328 views

What is the magnetic quadrupole moment of a nucleus in cylindrical coordinates?

What is the magnetic quadruple moment of a nuclei in cylindrical coordinates? The quadrupole moment of a nucleus is zero in spherical coordinates but in the cylindrical coordinates it can't be ...
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Why can Hiroshima be inhabited when Chernobyl cannot?

There was an atomic bomb dropped in Hiroshima, but today there are residents in Hiroshima. However, in Chernobyl, where there was a nuclear reactor meltdown, there are no residents living today (or ...
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78 views

Finding radioactive nucleus given table of values

Question Measuring the number of decays per minute $N(t)$ of a radioactive source every four days we have that: $N(t=0):=N_0=200$, $N(t=4)=141$, $N(t=8)=100$, $N(t=12)=71$, where $t$ is measured in ...
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1answer
112 views

Containement system of a nuclear reactor: role of the water moderator

In a modern nuclear reactor for example a PWR there are multiple containment systems which prevent the release of radioactive material into the environment and shield the environment from the ...
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532 views

Speed of neutrons in a nuclear reactor

How fast (in $\frac{\mathrm{m}}{\mathrm{s}}$) are typical neutrons before and after slowing down in a nuclear reactor (with U-235 and $H_2O$ as moderator)? Do you have any reference for the values?
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Adding many more neutrons to a nucleus decreases stability?

If you take any large nucleus and add protons to it, the electrostatic repulsion between them will make the nucleus more unstable, because the electrostatic force between them is more repulsive at a ...