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

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Why do you need debroglie wavelength less than nucleus diameter to probe a nucleus via deflection? [duplicate]

e.g. you need to give enough energy to electrons to probe a nuclear structure via deflection.
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51 views

Gamma spectroscopy – What is this structure?

What is this strange structure in the gamma spectrum between 450 and 550 keV (below) around the peak at 477 keV? The spectrum seems to rise to a plateau (almost like a small Compton plateau) around ...
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82 views

Length of time interval for an atom in excited state to drop to lower energy level [duplicate]

This is either a basic question or one that doesn't make any sense, but here goes. If I have an atom in an excited state (1st energy level or 2nd or more), how long does it take to drop to a lower ...
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105 views

How do protons and neutrons interchange?

I recently read in a book that a nucleon with +1/2 isospin is a proton and if the isospin is changed to -1/2, it is a neutron, so it is the same particle in different states. If a proton has a ...
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53 views

Coincidence summing in gamma spectrum

Question on coincidence summing here. I've been reading about the coincidence summing effect when a radionuclide has two energy levels that decay to another state in rapid succession. There is also ...
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90 views

Relationship between time, separation and neutron transfer probability?

As an ansatz, suppose we know that when a smaller nucleus is incident upon a larger one with 1 MeV of kinetic energy, there is a nontrivial probability that a neutron will tunnel from the smaller to ...
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1answer
158 views

When i tear a paper, can i accidentally create nuclear fission?

I know it's a stupid question... but when I tear a paper i may coincidentally split it and create nuclear fission. When i tried experimenting, by tearing the paper for HELLKNOWS how many times, I ...
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211 views

What is this jump in U235 fission yields?

Is it an artifact? (I have drawn the black line). Or can anybody explain it theoretically? The plot is the "235U Chain 14MeV" provided in the website https://www-nds.iaea.org/ Some sources call it ...
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7 views

Have the BaF2 scintillator have a strong correlation with the alimentation current that cause the shifting of the centroids?

In gamma gamma correlation I suspect the presence of sistematic error maybe caused by a non optimal alimentation voltage according to someone there is a quadratic correlation between centroids ...
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72 views

How can a black hole be a cause of a Big Bang? [closed]

Is it possible that Big Bang occurred as a result of the black hole formation - that is the matter compressed so densely that it "exploded" within the boundaries of its horizon and became a what we ...
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36 views

Why asymmetric fission product is so enhanced?

The thermal fission yield of usual Pu, U mix https://en.wikipedia.org/wiki/Nuclear_fission#/media/File:ThermalFissionYield.svg is tuned in a way that practically ignores symmetric yield. But if we ...
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18 views

Can an excited nucleus capture a second neutron? [duplicate]

I am wondering if is it possible to have the following scenario: Nucleus captures neutron. Nucleus is excited but does not relax through decay but captures another neutron. Maybe it is possible if ...
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60 views

Nucleon-meson interaction

Suppose interaction lagrangian between neutron-proton doublet and $\pi$-mesons: $$ \tag 1 L_{\pi pn} = \bar{\Psi}\pi_{a}\tau_{a}(A\gamma_{5} + B)\Psi , \quad \Psi = \begin{pmatrix} p \\ n\end{pmatrix} ...
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100 views

What produces this 477 keV spectral line?

Question about a specific line on a gamma spectrum, here. Below is a background gamma spectrum observed by a Ge[li] detector. I've been able to identify all the lines with mostly certainty, apart ...
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1answer
45 views

What does the g mean after the isotope given?

I'm familiar with notation such as Sc-44m standing for the meta stable state of Sc-44. What does Sc-44g mean? There are a few examples of this notation; here's one: ...
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4answers
176 views

Do neutrons in an atomic nucleus exert strong force on each other?

If they do, then why do we never see clumps of neutrons assembled into "atoms" without protons? Or are neurtons mutually repelled by the strong force?
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2answers
77 views

Estimation of the age of Earth

By calculating the ratio of U-238 to Pb - 209 the age of the earth can be estimated. Is it not a possibility that non radioactive lead already there formed during the birth of earth it self alter the ...
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1answer
42 views

Gamma spectrum: Question about cross sections

If I have a gamma spectrum and I suspect that I should have an isotope, Fe-59 for example, present in the environment, I will then look here: ...
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3answers
661 views

Fission of U-235 produces Cs-137 along with…?

Question about Nuclear fission in general, here. If I have the fission of U-235 and I know that one of the products is Cs-137, is there a way of figuring out the other product? Should there be ...
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2k views

How much energy is released from the splitting of a single hydrogen atom?

My question is a fairly simple one that I cant seem to find on Google: How much energy, in both technical and laymans' terms, is released from the splitting of a single hydrogen atom?
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180 views

Matter to energy conversion

Okay so I have a question, during a nuclear explosion or particle/antiparticle annihilation, matter is converted into energy. How do I determine if a from a explosion will come lets say a small ...
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2answers
231 views

What is meant by mass defect of a single neutron or a single proton?

As per my understanding The mass defect of a nucleus represents the mass of the energy binding the nucleus, and is the difference between the mass of a nucleus and the sum of the masses of the ...
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2answers
64 views

Fission producing Cs-137

This is I suppose quite a precise question about Nuclear fission. What produces, aside from U-235, via a fission process, Cs-137? Does any isotope of Actinium, for example, undergo a fission process ...
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1answer
425 views

Should I observe single/double escape peaks for all energies above 1022 keV

I have already asked a question similar to this, but that question was specifically relating to the case of K-40. I'm going to generalize it to any case My question is to do with the field of gamma ...
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1answer
24 views

How to choose which elements to use when synthesizing an ultra-heavy element?

I've been told that synthetic ultra-heavy elements are produced by bombarding a light nucleus into a heavy one, and that several combinations are (at least in theory) possible, as long as the sum of ...
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1answer
44 views

Why do I not observe single/double escape peaks for K-40

A question on gamma spectrometry here. If I'm looking at a background gamma spectrum with a big peak at 1460KeV (approximately 180 counts) and I attribute this peak to the presence of K-40, should I ...
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1answer
58 views

Nuclear decay of V-48

I have a question on the "decay" of Vanadium-48. The reason it's in inverted commas is because I'm not sure whether decay is the right word. Basically what I'm trying to work out is whether it's ...
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135 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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3answers
156 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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1answer
84 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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46 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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40 views

Gamma Spectroscopy - Why no Intensity level for Neutron Capture?

I'm undertaking a bit of work looking at a Background Gamma Spectrum. On the spectrum, I have a clear, tall line at 834 KeV. I have a PDF file of a table of Gamma Spectra (ordered in energy) from ...
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2answers
65 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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128 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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Why didn't the Big Bang create heavy elements?

In the case of a supernova explosion it is possible to create heavy elements through fusion. Supernovae have a tremendous amount of energy in a very small volume but not as much energy per volume as ...
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49 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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3answers
132 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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42 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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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
138 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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232 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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1answer
60 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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4answers
387 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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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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55 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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101 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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14 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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1answer
229 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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301 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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58 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 ...