Nuclear physics is the study of the composition, behavior and interaction of atomic nuclei and their constituent parts.
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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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89 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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54 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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106 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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1answer
805 views
Does the Breit Wigner formula apply to intermediate virtual particles?
Breit Wigner Formula describes the cross section for interactions that proceed dominantly via a intermediate particle (O*) A+B → O* → C + D:
$$σ = \frac{2\Pi}{k^{2}}\frac{Γ_{i}Γ_{f}}{(E-E_{o})^{2} + ...
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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
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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
42 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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What happens if we put together a proton and an antineutron?
A hydrogen nucleus consists of a single proton.
A 2-hydrogen (deuterium) nucleus consists of a proton and a neutron.
A tritium nucleus consists of a proton and two neutrons.
This makes me wonder how ...
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What does $\mathrm{A}_r(\mathrm{H})$ represent when calculating the average natural weight of an elemental atom? [migrated]
I have a question that explains the weights and abundances of various hydrogen isotopes, and the question concludes by asking to:
Calculate the atomic mass of hydrogen $\mathrm{A}_r(\mathrm{H})$ ...
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536 views
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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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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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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1answer
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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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1answer
63 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
164 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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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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90 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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$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)$$
where $K$ is the total kinetic energy, and $E_0$ is the ...
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2answers
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Harmlessness of a pure alpha decay particle
From my high school physics class I remember that there are some particles which exhibit pure alpha decay (i.e. alpha decay to there stable isotope), like Po-210, Po-211 and Bi-209.
What I also know ...
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1answer
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Calculate energy from an reaction [closed]
I'm trying to calculate the released energy from a reaction.
The radioactive substance polonium decays according to this formula:
$$^{210}_{84}\mbox{Po} \rightarrow \mbox{X}+^4_{2}\mbox{He} $$
At ...
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57 views
How long would it typically take to develope nuclear weapons these days? [closed]
This question is a bit related to politics.SE too.
These days there's a lot of concern about development of nuclear weapons in countries that are believed by United States to support terrorism.
As ...
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1answer
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$\require{mhchem}$ $\ce{\beta^{+}}$ decay for $\ce{_9^18F}$, computing $\Delta m$
For the decay:
$$\require{mhchem}\ce{_9^18F\to_8^18O +e+ +{v}}$$
To compute $E$, I need $\Delta m$, the provided answer looks like:
$$m_i = 18.000938~u$$
$$m_f = 17.999159~u + 2~(5.49 \times ...
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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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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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The Hartree solution of two harmonic oscillator coupled by potential $V \propto ({\bf r}_1-{\bf r}_2)^2$ [closed]
$H={\bf p}_1^2+{\bf p}_2^2+{\bf r}_1^2+{\bf r}_2^2+x({\bf r}_1-{\bf r}_2)^2$.
$x$ is the coupling factor.
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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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1answer
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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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2answers
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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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Approximately how much would a LFTR cost? [closed]
Would anyone happen to know how a LFTR costs?
Please could you include the efficiency and payback time.
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1answer
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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 ...
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nuclear fission and half life
Why is the alpha, beta or gamma decay of an unstable nucleus unaffected by the chemical situation of an atom, such as the nature of the molecule or solid in which it is bound? The chemical situation ...
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1answer
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How was Be-8's Half-Life of 7E-17 Second Determined?
Radionuclides occur with half-lives in a vast range of over 37 magnitudes as listed in this site. In question 7584, Lubos Motl explained how Gyr half-lives were determined. This method doesn't appear ...
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Radioactive Decay
Problem:Nuclei of a radioactive element $\Bbb X$ having decay constant $\lambda$ , ( decays into another stable nuclei $\Bbb Y$ ) is being produced by some external process at a constant rate ...
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1answer
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Why is the Wick contraction in HFB or BCS equal to a single-particle density?
I'm trying to understand how in Hartree-Fock-Bogoliubov
(HFB) or BCS theory we can write a product of creation/annihilation operators as single-particle densities under the guise of "Wick's theorem".
...
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Find mass of Plutonium in alpha decay [closed]
I did:
$$\Delta mc^2 = (m_{Pu}+m_{U}+m_{He})c^2$$
$$\frac{5.24 \times 10^6 eV}{(3 \times 10^8)^2} = m_{Pu} + 235.043924 + 4.002603$$
$$m_{Pu} = 239.0465$$
But answer is 239.052157, slightly ...
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What stabilizes neutorns against beta decay in a neutron star?
Free neutrons are known to undergo beta decay with a half-life of slightly above 10 minutes. Binding with other nucleons stabilizes the neutrons in an atomic nucleus, but only if the fraction of ...
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1answer
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Should the expression for energy conservation in alpha decay include the mass of electrons?
Let $M_P$, $M_d$, $m_\alpha$, $m_e$ and $Q$ the mass of the parent nucleus, daughter nucleus, alpha particle, electron and the disintegration energy, respectively. I understand that applying ...
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Energy conservation in nuclear reactions and radiactive decay
Reading "Fundamentals of Nuclear Physics" by Atam P. Arya, I understand that in a nuclear reaction, let say $x+X \to y+Y$ meaning that "when a particle $x$ strikes a target nucleus $X$, the outcome of ...
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Which pion is mediator in nucleon-nucleon interaction
In nucleon-nucleon interactions of n-n, p-p, n-p how do you determine which pion is the mediator?
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Why the pion does not get mass under Spontaneus breaking of chiral symmetry, but the quarks do?
Some sources state that when the mass of a quark goes to zero, it allows for Spontaneous Breaking of Chiral Symmetry and gets a constituent mass of about $200\, \mathrm{MeV}$.
Other sources state ...
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Why is a pion so light compared to a neutron or proton?
A pion is made out of a pair of up and/or down quarks. A neutron or proton is three up or down quarks. So naively I'd expect a pion to be about 2/3 the mass of a nucleon.
In fact it's less than 1/6 ...
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1answer
90 views
What is the lowest possible theoretical temperature that nuclear fusion can occur at?
I am not talking about the pseudo-science of so called cold fusion I am interested in what temperature you can get away with to produce fusion reaction. I was thinking in terms of micro-fusion or at ...
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Does the strong (nuclear) force ever contribute to decay?
Does the strong (nuclear) force ever contribute to decay ?
Or is the weak nuclear force the only decaying force ?
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Interaction photons-matter and dimensional analysis
I know that when photons pass through matter, the law that describes the intensity in function of the thickness is:
$$I(x)=I_0 e^{-\mu x}$$
where $\mu = \rho \frac{N_a}{A} \sigma$ and ...
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2answers
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Coulomb barrier and proton evaporation
Why is it that neutrons evaporate from nuclei more easily than protons do?
Intuitively, since protons are electrostatically repelled (in addition to whatever nuclear forces they have in common with ...
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Alpha particle and helium nucleus
The symbol for the alpha particle is α or $α^{2+}$, it can be written as $He^{2+}$.
What I want to know is that, are they same? I mean alpha particle and helium nucleus are same or any subtle ...
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1answer
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Ratio of Size of Atom to Size of Nucleus
I have the following problem:
In nuclei, nucleons exists in nuclear energy levels and in atoms, electrons exist in atomic energy levels. The order of magnitude of nuclear energy is 1MeV whereas ...
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How is it possible to calculate the energy liberated by a given fission process?
How is it possible to calculate the energy liberated by a given fission process? For example, in the fission of a $^{235}$U induced by capturing a neutron?
