Nuclear physics is the study of the composition, behavior and interaction of atomic nuclei and their constituent parts.
1
vote
2answers
22 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.
...
-2
votes
0answers
29 views
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.
1
vote
1answer
29 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 ...
0
votes
0answers
20 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 ...
17
votes
1answer
383 views
Why can Hiroshima be inhabited when Chernobyl cannot?
In Hiroshima, atomic bomb was dropped, but today, there are residents in Hiroshima. However, in Chernobyl, there is no resident living today (or very few). What made the difference?
-4
votes
0answers
27 views
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.
0
votes
2answers
34 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 ...
3
votes
1answer
36 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 ...
0
votes
1answer
35 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?
2
votes
1answer
37 views
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 ...
6
votes
2answers
142 views
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 ...
0
votes
0answers
39 views
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 ...
3
votes
1answer
35 views
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 ...
6
votes
2answers
119 views
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 ...
0
votes
1answer
119 views
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 ...
4
votes
1answer
73 views
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 ...
1
vote
1answer
69 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 ...
0
votes
3answers
37 views
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 ...
1
vote
2answers
64 views
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 ...
1
vote
1answer
63 views
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 ...
1
vote
1answer
53 views
$\require{mhchem}$ $\ce{\beta^{+}}$ 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 ...
8
votes
4answers
174 views
Why are alpha particles such a prominent form of radiation and not other types of nucleon arrangement?
It is said in many textbooks that alpha decay involves emitting alpha particles, which are very stable. Indeed, the binding energy (~28.3 MeV) is higher than for $Z$-neighboring stable isotopes. But ...
0
votes
2answers
68 views
Bremsstrahlung: why is electron slowed/stopped by the positive nucleus?
I can't understand why the electron is slowed/stopped by the nucleus.
The electron is a negative charge and the nucleus is positive... they should attract each other...
-2
votes
1answer
66 views
Is speed of electrons in atoms a constant during explosions? [closed]
E.g. in exploding nuclear bomb or some other big explosions.
I mean if the speed of electrons as waves/particles is a constant or changes according to other "forces" involved?
5
votes
3answers
215 views
We're all star dust?
OK so we've all heard of this from Carl Sagan, Lawrence Krauss and others and we know the argumentation, I don't refute that. There are other examples, for instance I once calculated (this was before ...
6
votes
0answers
64 views
Does quark color contribute to “spin degeneracy” for QGP calculations?
Like the title say, does quark color matter in counting contributions in a early universe plasma (QGP), as when adding up the total plasma energy density, or is it just spin? The book I have (Pathria) ...
4
votes
2answers
128 views
Mass defect- From where mass is being lost?
As a school student, I have wondered while studying mass defect the following mysterious problem
My assumption
Just like a car's mass is constituted by each part of it(i.e total mass of car will be ...
2
votes
1answer
40 views
Ground states in the shell model for odd-even nuclei
I understand that even-even nuclei (Z and N number) have zero spin because of pairing.
Even-odd nuclei have the spin of the odd nucleon, and parity is given by $(-1)^L$ - so my question is, ...
2
votes
1answer
57 views
Why is the total interaction cross section larger for incident particles with lower energy?
The cross section of a nuclear interaction is a measurement of the probability of that interaction occuring. These probabilities are typically presented in terms of barns ($10^{-28}$ m$^2$) as a ...
2
votes
1answer
40 views
Why did Otto Hahn use neutrons to generate transuranium?
In physics textbooks with chapters about nuclear fission there is often a historical introduction about Otto Hahn. That he tried to generate transuranium but discovered the nuclear fission.
If you ...
1
vote
1answer
76 views
Calculate/estimate power of a fission bomb
I have some questions about the released energy and power of a nuclear fission bomb.
What are the key dependencies of the power of a fission bomb?
Is it true that the power of a fission bomb depends ...
1
vote
1answer
61 views
How to superimpose Wood-Saxon and Coulomb potential?
I have just written a simple simulation that models the tunnel-effect of alpha-particles for $^{212}$Po and $^{238}$Ur. In this simulation, I approximate the potential of the nucleus by a simple ...
3
votes
1answer
281 views
Kinetic energy of alpha-particle in $^{212}$Po decay
Admittedly, Nuclear Physics is not my strength. I'm writing a simulation to model alpha-decay. So far, I have looked up the values of the kinetic energy of the alpha particles that are emitted in a ...
3
votes
0answers
30 views
What is the difference between the KDEMO and DEMO projects?
I'm writing a paper on the future of fusion technology and I can't seem to find the difference between Europe's DEMO experiment and Korea's KDEMO except for the fact that they are both planned to ...
-3
votes
1answer
61 views
Can an Anti nuclear atom be synthesised so it can neutralise the effect of nuclear atom [closed]
as we have studied that if the number of electron becomes equal to number of proton then that particle becomes neutral. so what will the energy or procedure required to break the chain reaction in ...
0
votes
0answers
222 views
Difference between Nuclear Bomb and Atomic Bomb? [closed]
What's the difference between the Nuclear Bomb and the Atomic Bomb? Or are they necessarily the same thing?
0
votes
1answer
49 views
What does the Atomic Form Factor means?
I was reading about Nuclear Physics and the autor mentioned something about the Atomic form factor, something relationated with the Fourier Transform of the espacial distribution of the electric ...
3
votes
0answers
46 views
What fraction of nuclear excited states are known?
I was reading a paper today claiming observation of a new $2^+$ state in $^{12}\mbox{C}$, which would correspond to a sort of rotationally excited Hoyle state. Looking at NuDat reveals that this ...
0
votes
1answer
77 views
Developments originating from $E=mc^2$
What kind of significant impacts have originated from $E=mc^2$.
Generally, it is regarded as the most famous equation of all time. Except for nuclear energy (fission and fusion) I do not know any ...
4
votes
2answers
121 views
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 ...
32
votes
3answers
1k views
Can the solar system really fit in a thimble?
Almost every time somebody talks about atoms, at some point they mention something like this:
If we remove the spaces between the atoms and atomic components, we can fit the solar system in a ...
1
vote
1answer
34 views
Nuclear transition notation
I have a question which asks me to determine what x is for the following nuclear transition
$$^{29}Si(\alpha, n)X$$
But I don't have any idea what this notation implies.
Another example:
...
3
votes
2answers
79 views
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 ...
-1
votes
1answer
100 views
Determining energy of gamma-rays after alpha-decay of Am-241
So it turns into Np, and electrons just falling into 'free new' levels and emmiting, right?
Give me a link where to read, please, if it's very easy to answer.
3
votes
1answer
107 views
Gamma Ray LASER Theory and Technology
I am aware that a similar question has been asked by someone else in the past, but in a very general form. Due to the physics interest and technology, in this question I put emphasis on the detail of ...
4
votes
0answers
58 views
Can we excite a nucleus by means of very intense low energy gamma-photon irradiation?
The phenomenon of multiphoton ionisation of atoms has been studied, both theoretically and experimentally, for several decades. Intense LASER beam devices are the apparatuses used for the experimental ...
3
votes
4answers
235 views
How can the nucleus of an atom be in an excited state?
An example of the nucleus of an atom being in an excited state is the Hoyle State, which was a theory devised by the Astronomer Fred Hoyle to help describe the vast quantities of carbon-12 present in ...
0
votes
2answers
67 views
Nuclear based wireless power?
I would like to ask if there is any Nuclear process which can be used to produce a wireless power ?
Is there any nuclear process can be radiate to the environment with no harm to human beings?
...
0
votes
0answers
32 views
What is this underground nuke test name and params? [closed]
Here is a famous video of an underground nuclear test:
http://www.youtube.com/watch?v=S1f6vbiuUt0
What are its characteristics?
4
votes
3answers
90 views
Does a Photon leave trace in a silicon tracker?
I am having this image from ATLAS Detector.
In gray you can see the ATLAS's Si Tracker.In Green you see the Electromagnetic Callorimeter. In red there is the Hadron Callorimeter and in Blue there ...
