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

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Protons and Neutrons Overshoot Actual Mass? [duplicate]

When I add up the mass of 6 protons and 6 neutrons in amu, I get a mass that is greater than the mass of carbon. I thought that it should be the other way around, because I have not including binding ...
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Why do nuclear bomb explosions create an array of visible electric discharges in the form of lightening in the upper atmosphere?

I've seen videos on the internet, showing nuclear bomb test explosions, and there appears to be a large amount of visible lightening discharging numerous times over the development of the mushroom ...
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Nuclear medical physics [on hold]

How do you calculate the half life of daughter isotope (in secular equilibrium) Given a table of countrate(cps) and time (min). Like: Time (minutes) Count Rate (cps) time (min) Count Rate ...
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25 views

Regge trajectories for higher spins

I have read that Regge theory did/does predict higher spin meson states, but that at higher spins the data becomes fuzzy for spins greater than 4. Why is this so? In the book "A Brief History of ...
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Fraction of kinetic energy carried by neutrons after D-T fusion [closed]

I am trying to answer the following question: Ignoring the initial kinetic energy and momentum of both particles in a D-T fusion reaction calculate the fraction of the released kinetic energy ...
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94 views

Why U235 over U238?

There are 3 isotopes of uranium that can be found in nature[1]: U234, U235 and U238. For a chain reaction to last there must be a high amount of neutrons contents and by comparison, U238 contains 92 ...
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37 views

Discrepancy problem in lithium?

Why is there a discrepancy between the amount of lithium-7 predicted to be produced in Big Bang nucleosynthesis and the amount observed in very old stars?
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Can we predict the half-lives of radioactive isotopes from theory?

Is there any way to predict the half-lives of radioactive isotopes from theory (that is, using only theoretical considerations, without using data about the decay)? For example, could we predict that ...
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Carbon-14 formation in atmosphere

Wikipedia says Carbon-14 is formed in the atmosphere by the reaction: 1n + 14N → 14C + 1p This looks like neutron capture. However, I would expect neutron capture to result in 15N. However, "proton ...
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Semi-empirical mass formula

The mass formula is given by $M(Z,A) = ZM_{p}+(A-Z)M_{n}-a_{1}A+a_{2}A^\frac{2}{3}+a_{3}\frac{Z(Z-1)}{A^\frac{1}{3}}+a_{4}\frac{(Z-A/2)^2}{A}+a_{5}A^\frac{-1}{2}$ So I am just wondering here what ...
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Why doesn't a nuclear reactor's filament deform?

Why doesn't a nuclear reactor's filament deform? The filament in the core of a nuclear reactor is usually made of uranium rods. So in the nuclear reactions the neutrons constantly move from filament ...
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Mass of an Atom

So the mass deficit of an atom, denoted by $\Delta M(Z,A)$, is given by the following formula, $\Delta M(Z,A) = M(Z,A) - Z(M_{p} + m_{e}) -NM_{n}$ However since the rest mass of an electron is a lot ...
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Binding Energy of an atom

I would like to know if there is any difference between the binding energy of a nucleus and the binding energy of an atom and what exactly do we mean when we say Binding energy per nucleon.. Edit to ...
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25 views

What is the charge/matter distribution?

I am a mathematics student who is doing an introductory course in nuclear physics and since the course is rather elementary a lot of the definitions/derivations are skipped which makes it quite tough ...
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Can Dark Matter just be clumps of Neutrons

I was wondering about Dark matter, and it occurred to me that why could it not be just nuclei of Neutrons with no electron cloud. Is it possible for such things to exists. Can Neutrons bond to one ...
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nuclear fusion scaling with reactor size

Thinking about physics of thermonuclear fusion, I have always intuitive sense, that making fusion feasible is matter of reactor size. In other words I feel like: if the fusion reactor is big enough ...
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25 views

What is the difference between mass defect and mass deficit?

Is there any difference between the mass defect and the mass deficit? I have read that the mass defect of a nuclide is never negative and have also been told that the mass defect is the same as the ...
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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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65 views

Why can “slow” neutrons trigger fission?

My understanding of nuclear fission is that some massive isotopes such as uranium-235 are unstable and when split via fission there will be a "slow" neutron. This slow neutron will hit another ...
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What happens to the nucleus energy when it decays?

When an atom decays into another atom, what happens to the potential energy of the nucleus ? I think it will get more negative because, in general, through fission and fusion an atom tries to get a ...
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58 views

Why is energy released during decay?

Why is energy released when an atom decays into another atom, even though no energy is added? What does the mass defect mean? Is it because a nucleus which decays is unstable (proton/neutron = 1)? ...
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In an all-out nuclear war, how long should remain sheltered? [migrated]

Fairly common in sci-fi literature is the scenario where the Earth is destroyed by an all out nuclear war. Typically, the protagonist have survived by remaining in underground shelters for decades ...
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Could the LHC be used for fusion experiments? [duplicate]

Just looking at the beam energy and peak power for the LHC, 360 MJ and petawatts, respectively, dumped in about 100 µs, would this be sufficient to do useful fusion experiments?
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Stone vs. Atomic Bomb

What would do more damage, a B53, a 9 megaton uranium bomb, or a medium sized stone (2 kg) stone throw at 90% the speed of light. One thing that I know that will have to be considered is that fact ...
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84 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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mirror nuclei: accounting for the difference in mass between nuclei

I was wondering if anyone here could guide me in the right direction with respect to the following problem: two nuclei are considered mirror nuclei if interchanging the neutrons and protons turns one ...
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The Interior of A Nucleon

Just like, in a Bohr model, the atom has a particular structure, what is it like inside of a Nucleon? Like, are there particular ways the quarks are arranged, and what about the binding energy that ...
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Electron Beam Welding equation

I am studying for a nuclear physics course right now and came across a question and topic that sparked my interest - Electron Beam Welding. As I understand it, the process heats up the metal by ...
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What is the energy threshhold to produce Cherenkov radiation?

I am in a nuclear course right now and am getting some misleading information from different sources. I am trying to figure out what the minimum total energy is that a proton must have in order to ...
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What is the “penetrability factor”?

I have read/heard this term a few times in nuclear physics papers. I'm guessing it has something to do with the Coloumb barrier of a nucleus. Could you maybe explain what this "penetrability factor" ...
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30 views

Are nuclear processes the only processes that release more energy than is input?

Are the nuclear processes of fission and fusion the only known processes or events that release more energy than is input to create those processes? I know I am being a little vague; I do not know the ...
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49 views

The semi-empirical formula and $E=mc^2$

The semi-empirical formula is used to find the binding energy of a nucleus. But if you know the mass of a nucleus and the number of neutrons and protons that this nucleus consists of (and you know ...
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136 views

What was Feynman's famous formula?

In Welton(1983), Memories of Feynman, Welton mentions two formulas which he denotes as Feynman's Famous Formula (FFF) and FFF #2. Which famous formulas is he talking about? Is he maybe talking about ...
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Is a nuclear bomb in some sense a bullet travelling at the speed of light, but along time rather than along space?

Apologies if this is a silly or perhaps obvious question, but $E=mc^2$ just looks so much like classical kinetic energy (except for the factor of 2). So I'm thinking of the to-be-fissioned-away ...
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Electric Field inorder for Fusion to occur

If I want to do D-D -> He + n fusion in an electric field - what potential would I need? So I know the coulomb barrier is at $U=k^2 \frac{e^2}{10^{-15}} = 1.44 MeV$ This is when the strong force ...
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How does the number of neutrons in an atom affect the strong force?

How does changing the number of neutrons (making a different isotope) affect the strong force and therefore the protons and the overall atom?
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Electricity should deform the conductor then why doesn't it?

In electric current both negative particles and positive particles flow but in opposite directions. So why doesn't the conductor's shape deform because its particles are moving here and there? OR is ...
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PP Chain and CNO cycle relationship

At what temperature would the energy generation rates of the PP-Chain and CNO cycles be roughly equivalent? The dependences are so vastly different that I am wondering how and by what equations they ...
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62 views

Effective Coulomb barrier for deuteron

What is the effective Coulomb barrier for a Deuterium-deuterium fusion reaction? I am seeing temperatures of about $40 \times 10^7 K$ online, but have no idea how they are getting this. If we have ...
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What is the reduced width amplitude of an unstable state?

Particularly used in nuclear physics when describing the lifetime (i.e. partial decay width) of a resonant state (a.k.a resonance) is the term "reduced width amplitude". I have searched online, and ...
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Evidence that nuclei contain neutrons and protons (other than nucleons appearing if a nucleus is smashed)?

This may seem like a silly question, but I believe this to be very fundamental because the Standard Model of particle physics seems based on the axiom or assumption that neutrons and protons exist ...
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Is there a difference in the energy output of a nuclear fission reaction as opposed to fusion?

For example, if I split a Helium atom will I get the same amount of energy as when I fuse Hydrogen into Helium? If there is a difference, what will be the difference (in general not according to ...
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Do the nuclear reactions produced by different elements release different amounts of energy?

Does the nuclear reactions in an element like Uranium produce a different amount of energy than the nuclear reactions in Plutonium? I am not concerned with those elements in particular, they just seem ...
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Why does the 180°-pulse in mrt not sync all phases like the 90°-pulse does?

As far as i understand, in mrt with the constant field B0 pointing in the z-direction, the 90°-pulse "screws" some of the relaxed spins, so that the expectation value of their magnetic moment rotates ...
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What process happens in an IT nuclear decay?

I've been researching medical isotopes and alot of them decay by an IT path. Does anyone know what IT stands for? And what physical process is happening? Example: ...
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What happens if the Russians decide to nuke the Kola borehole?

I recently came across research on the Kola Superdeep Borehole in Russia. It's one of the world's deepest at 12 km (7.5 mi) down. If someone decided to hoist a nuclear weapon all the way down and set ...
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What does it mean for a state to have a negative partial decay width?

I don't understand what it means when a particular decay mode has a negative partial decay width. I'm guessing the total decay width for a particular system must always be positive (now that wouldn't ...
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During Nuclear fusion why Atomic mass of β becomes zero?

I would like to know during Nuclear fusion how/why Atomic mass of β becomes zero. For example: two Protons fuse to form a deuterium nucleus. Please see the attachment. Thanks
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How nuclear fission works in power plants? [closed]

As per the laws we are not able to see atoms (atom is microscopic). Then how does the nuclear fission works? *. In nuclear fission, splitting atoms is a exact calculation or probability(like we 1 ...
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Orbital angular momentum of nucleus?

For nuclei, I know that it is the $J^{\pi}$ that is usually measured/calculated, which is the spin-parity. I don't see "orbital angular momentum" of a nucleus very often. Now my notion of spin vs. ...