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

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Why is this nuclear reaction $p\to n+e^++\nu$ forbidden for a free proton? [closed]

Why is this nuclear reaction forbiden for a free proton? $$p\to n+e^++\nu$$ Where $p$ is the proton, $n$ is a neutron, $e^+$ is a positron, and $\nu$ is a neutrino. What i´ve been thinking is because ...
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117 views

Does the mass of a nucleus increase when it is excited to higher energy levels

If we consider an atomic nucleus that is excited to a higher energy level. This maybe due to absorption of gamma for example or as a result of some other decay or interaction. Would the mass of that ...
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398 views

Radioactive decay - What mechanism decides when an unstable nucleus decays?

My first question on Stackexchange (if it is formatted wrong or something please tell me so I know in future) - here it is: Given an unstable nucleus (exactly which nucleus is not particularly ...
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33 views

How the number of binary collisions increases with centrality faster than the number of participant in heavy ion collisions?

How the number of binary collisions increases with centrality faster than the number of participant in heavy ion collisions at different particle colliders?
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54 views

Probe the nucleus by using high energy particles

Why alpha particles would give better resolution than protons moving at the same speed? Can it be explained by Heisenberg uncertainty?
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134 views

What happens to mass during beta decay?

Sorry for being ignorant, but I'm in high school and our chemistry teacher barely went over beta decay. I decided to do some research and learned that in β+ decay, positrons are emitted from protons ...
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119 views

Why can't a nuclear reactor be used as a rocket motor?

Nuclear fission, and potentially fusion, reactors generate vast amounts of energy, primarily as heat. What stops us from harnessing that energy to propel spacecraft at or above escape velocity from ...
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2k views

Absolute isotope activity in a nuclear fallout

I've seen nice graph showing relative activity of each isotope in Chernobyl fallout: Could anyone suggest similar graph or raw data but for absolute isotope activity for the case of nuclear ...
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Diffusion of magnetization (NMR)

In the context of MRI I'm trying to understand the mechanisms of magnetization diffusion. Consider a sample that is magnetized by an external magnetic field. We have displacement of magnetic moment ...
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67 views

Does chemical energy contribute to mass? [duplicate]

Does chemical energy contribute to the mass of an object? I don't mean the bond energy, but the possible energy that could be released (i.e. Does an atom of oxygen and a molecule of hydrogen (H2) have ...
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Why is boron so good at neutron absorption?

Why is boron so good at absorbing neutrons? Why does it have such a large target area compared to the size of its nucleus?
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147 views

In a nuclear reaction, where does the energy go?

Lets say two hydrogen fuse together, where does the energy released go? Is it carried away as momentum imparted on the helium atom? Is it carried away in neutrinos? Is it carried away as gamma rays? ...
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197 views

nuclear physics- Energetics and Mechanics of Nuclear Reaction Homework [closed]

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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151 views

Mass loss for Fusion energy? [closed]

I am thinking how you can estimate the mass loss of the fusion energy for 1 kWh. I think you cannot use Einstein's $E=mc^2$ to calculate the mass loss in the fusion reaction of the Sun. How can ...
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253 views

Sommerfeld Parameter Confusion

In almost every reference site I can find, the Sommerfeld parameter $\eta$ is explicitly stated as $$\eta=\frac{Z_1Z_2e^2}{\hbar \nu}=\frac{Z_1Z_2e^2}{\hbar }\sqrt{\frac{\mu}{2E}}$$ Where $Z_1$ and ...
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51 views

Characteristic Ka X-rays [closed]

In an experiment one observes the characteristic Ka X-rays of two elements at energies of 6.930 and 7.478 eV. The higher energy line is due to Ni. What element is responsible for the lower energy ...
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39 views

Meaning of 'nuclear surface vibrations'?

Would like to know the meaning of nuclear surface vibrations as mentioned by Bohr in his paper titled 'The coupling of nuclear surface vibrations to the motion of individual nucleons'. The paper talks ...
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50 views

Positive/negative octupole moment of nuclei?

Does octupole moment of nuclear charge distribution show any positive/negative character, like the quadrupole moment does? Quadrupole moment has prolate and oblate types, but what about ...
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144 views

What is the difference between zero background radiation and field background radiation in Nuclear Physics measurements?

Can someone please explain the difference between these two terms (Zero Background Radiation and Field Background Radiation) used in radiometric prospecting measurements?
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How do control rods work?

I understand the basic idea of nuclear fission: put a bunch of fissionable material together and let the neutrons fly. An atom gets split, kicking out a few more neutrons, which split other atoms, ...
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146 views

Why do heavy nuclei have half lives

Why do heavy nuclei have half-lives if they are unstable why do they take millions of years to break down in some cases why don't they simple do it instantly? What makes them stay together?
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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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2answers
143 views

Could I turn into a nuclear bomb?

Just out of curiousity, could the nuclei of our atoms split via quantum tunnelling, thereby leading to nuclear reactions and ultimately turning us into atomic bombs? I know that this is ...
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19 views

What combination of stable GE isotopes make up the germanium in a Ge(Li) spectrometer

I work with a Ge(Li) gamma spectrometer. I'm trying to work out the different populations of stable Germanium isotopes in it. I'm trying to model the unrealistic scenario where none of these isotopes ...
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Modelling populations of GE isotopes

I asked a question similar to this here: What combination of stable GE isotopes make up the germanium in a Ge(Li) spectrometer And got some very good answers. This question is instead based on the ...
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564 views

Why can't electrons be found inside the nucleus if there are infinite number of orbitals?

If there are an infinite number of orbitals, we can assume, that they can be present in any point in space. If that is correct, why do we not find electrons in the nucleus? I study in high school. ...
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Models for populations of decay products

I'm looking to create a population model for the specific nuclides in a neutron spallation source. The source is a target (Tantalum clad Tungsten) which is being bombarded with protons, and in turn is ...
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96 views

How does neutron reflection work?

What I mean here isn't what is it used for, but what's actually going on with the reflector. There are a lot of sub questions to this. how much energy is lost in the act of reflection. not ...
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32 views

Notation on chart of the isotopes

I recently purchased a complete chart of the isotopes, (this one: https://shop.marktdienste.de/shoppages/produktuebersicht.aspx ) and have it on the wall next to me in work. The different coloured ...
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33 views

Nomenclature of nuclear excited states

I read in an online portal about $^{112}$Sn nucleus making a transition from $0_{g.s}^{+} \rightarrow 2_{1}^{+}$ state. Also, some higher excited states were named as $0_{2}^{+}$, $3_{1}^{-}$, etc. ...
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834 views

Can we generate infinite energy by successive fission and fusion reactions?

Fission divides one Helium atom into two Hydrogen (Deuterium) atoms. And fusion, once again, puts together those two Hydrogen atoms into one Helium atom. In both reactions, overall output energy is ...
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488 views

Weak contribution to nuclear binding

Does the weak nuclear force play a role (positive or negative) in nuclear binding? Normally you only see discussions about weak decay and flavour changing physics, but is there a contribution to ...
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108 views

What would happen if you split an antimatter nucleus? [duplicate]

If we had the huge money required to make it, could it be used as a weapon more destructive than a regular nuclear bomb? Here it would undergo fission AND annihilate regular particles, so...?
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50 views

Oscillation of nucleons mediated by polarizing electron charge on opposite ends of the nucleus?

Assuming I have a nucleus and its known that there are nucleons inside its shell. Lets say I have an electron that alternates its position from the top of the nucleus to the opposite bottom, back and ...
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48 views

minimum hyperbolic distance for Rutherford Scattering

I saw in a textbook that gave the minimum distance for a hyperbolic trajectory in Rutherford scattering is given by $$r_{min}= ...
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100 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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How massive can an atom get?

After reading this thread, it appears to me that creating a new element is a game of chance some sort of an art. It also appeared to me that the higher you go, the harder it is to make an element. ...
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297 views

Tritium decay is spontaneous even if the binding energy of tritium is higher than the binding energy of 3He. Why?

Given this nuclear reaction: $^3_1\mathrm H\to {}^3_2\mathrm{He}+e^-+\bar{\nu}$ and knowing the binding energies: $BE(^3_1\mathrm H)=8.48 \,\mathrm{MeV}$ $BE(^3_2\mathrm{He})=7.72 \,\mathrm{MeV}$ ...
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422 views

Island of Stability

When I was much younger, I remember being fascinated by the thought of an Island of Stability at very high atomic numbers. However, I have not heard much on this and I was wondering Did this idea ...
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1answer
44 views

Doubly magic isotopes

I understand the definition of a magic number in nuclear physics to mean a number of either protons or neutrons to completely fill a nuclear shell. I see here the term "doubly magic" used for 78Ni: ...
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401 views

Gamma spectroscopy - Table of radioactive isotopes with gamma energy search

For anyone doing gamma spectroscopy by hand, the task is considerably eased by tables like this: http://nucleardata.nuclear.lu.se/toi/ Where not only can you search for particular nuclides, but you ...
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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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Gamma spectroscopy - Do annihilation photons produce a backscatter peak?

Below is a diagram of part of a structure which I find in a gamma spectrum taken from a hall in which a neutron source is undergoing spallation. The structure which I'm interested in can be seen ...
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97 views

Color Force & Nuclear Force [closed]

I was wondering if the color force and nuclear force are both sub-forces of the Strong Interaction? If so is the Strong Interaction responsible for any other forces?
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42 views

Reading ensdf files

I understand that this is more of a computing question, but I still think the appropriate place to ask it is here. The Evaluated Nuclear Structure Data Files are on the internet, available for ...
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Does core of a proton exist? [duplicate]

I understand a proton is made up of quarks/gluons. I want to know if a proton has an actual core? Also whether protons have a core/surface temperature.
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236 views

Feynman-Bethe Critical Mass Formula

According to the historical lore of the making of the atomic bomb at Los Alamos, Richard Feynman and Hans Bethe supposedly worked out a formula for the critical mass for the core of the A-bomb. Is it ...
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622 views

Was the early Earth radioactive?

I've been reading of the (surprising) fact we are uncertain on whether there is nuclear fission in the center of the Earth or not (yet we know so much detail on structures at the other end of the ...
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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 ...