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

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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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26 views

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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35 views

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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62 views

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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48 views

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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73 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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324 views

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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163 views

What is an 'S-factor' in nuclear physics?

I have seen the "S-factor" in many places, but I've never read an explanation of what it actually is. I have read that it is related to the cross-section of a reaction, but that's about it.
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289 views

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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69 views

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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81 views

Working of fusion reactor

The present type fusion reactors use the magnetic confinement technique for the production of energy. Moreover only 48% for the energy is only absorbed and converted into useful energy . Why we are ...
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44 views

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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41 views

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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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 is the required thickness of concrete needed to entomb a leaking reactors emissions?

What is the minimum thickness of an aggregate concrete membrane to prevent radioactive particles from escaping a broken reactor? I am interested in calculating the amount of concrete required to ...
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89 views

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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45 views

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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39 views

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 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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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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Can a nuclear reactor be used as a space-based weapon?

Imagine you have a ship, running on power from a nuclear reactor. We will assume this ship uses some kind of advanced technology that allows nuclear reactors to function in a microgravity environment. ...
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What practical issues remain for the adoption of Thorium reactors?

From what I've read on thorium reactors, there's enormous benefit to them. Their fuel is abundant enough to power human civilization for centuries, their fission products are relatively short-lived, ...
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205 views

What's the difference between binding energy and separation energy?

My understanding of the two was as follows: the binding energy of a nucleus is, classically speaking, the energy needed to put together/take apart that nucleus completely (i.e. a measure of the strong ...
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Nuclear orbitals for nucleons [duplicate]

I'm currently taking a nuclear physics class, and of course, earlier courses taught me how electrons "moves" in orbits around the nucleus. In that case, it is their wave function that is spread out in ...
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422 views

Why are neutron absorption cross sections high at low incident energy?

For example, U-235 fission cross section looks like this: As I understand it, the resonances peaks correspond to discrete quantum states of the excited compound nucleus. As you go higher, the ...
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25 views

Nuclear physics

What is difference between proton radius and charge radius. I have seen a formula rp=sqrt(rc^2-0.8^2), where 0.8 is rms charge radius of an isolated proton, rc and rp are rms charge radius and proton ...
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Radiometric dating calculation [closed]

If a sample of zircon initially contains no Lead, find an expression for the ratio $$\frac{N_U}{N_{Pb}}$$ as a function of time? How do I do simplifications from this? Do I just go: ...
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Given the quadrupole moment of the nucleus as Q, is it possible to find the order of magnitude of the dimensions of the nucleus?

Given the quadrupole moment of the nucleus as Q, is it possible to find the order of magnitude of the dimensions of the nucleus? ( order of magnitude means approximate value to the powers of ten)
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How do scientists measure the spin-parity of a resonance?

I have seen many plots and data tables which display the cross-section vs. center of mass energy for a particular nuclear reaction at a given angle. Here is an example. You can see that there are a ...
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41 views

Why does the nuclear volume scale (roughly) linearly with number of nucleons?

As far as I know, it is the fermi repulsion that gives a collection of protons or neutrons its finite size. But this only acts on indistinguishable fermions. If the protons and neutrons do not repel ...
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60 views

Spin orientations

The concept of spin is purely a quantum mechanical effect, it is restricted to given values in given orientations. If hypothetically spin were a classical concept yet still of a fixed value, would its ...
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1answer
60 views

Pair production with nucleus

I've seen in other questions that pair production is not possible in vacuum, i.e. it needs a nucleus or something massive in order for conservation of momentum to hold. I've seen the derivation of ...
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Arrangement of neutrons and origins

I my physics textbook, it is given that atom consists of protons and neutrons. But my question is that how are they arranged in a nucleus of a heavy atom such as uranium?
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electrons inside nucleus and uncertainty principle [closed]

State the assumptions of the proton-electron model of the nucleus. Show that if one uses the Heisenberg uncertainty relation to estimate the speed of an electron inside a nucleus with a diameter of ...
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Spin and parity transition levels gamma radiation

Just a quick question regarding spin and parity. I am studying nuclear physics and I am just a tad confused with a concept about gamma radiation. Say I have ${^{20}_{10}Ne}$ And the lowest electric ...
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121 views

Is there a maximum number of neutrons of an isotope?

I wondered whether there is a maximum number of neutrons in an isotope. Or is there no maximum number? So, can an H-75 atom exist?
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60 views

Possible Meson decays

For an excited state $D_s^{**+}$ of the $D_s^+$ meson, a possible decay is $$D_s^{**+} \rightarrow D_s^+ \pi^0 $$ For which of the $1P$ mesons, i.e. $1^1P_1, 1^3P_0, 1^3P_1,1^3P_2$, is this decay ...
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How often does nuclear fusion occur within the human body?

I'm just curious. I figure atoms fuse occasionally just by chance, like quantum tunneling or rogue waves. Is this true? If so, any idea how often?
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Did Don Borghi's experiment show that neutrons can be synthesized purely from protons and electrons?

C. Borghi, C. Giori, and A. Dall'Olio published an article entitled "Experimental evidence of emission of neutrons from cold hydrogen plasma" appearing in Yad. Fiz. 56, 147-156 (July 1993) and Phys. ...
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102 views

Solution to Schrödinger equation

I'm trying to solve the Schrödinger equation for a given potential. With some assumptions I end up with: $$\frac{\hbar^2}{2M}\frac{d^2u(r)}{dr^2} = - \left(E - V(r)\right)u(r)$$ Since it's a square ...
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31 views

Centrality analogue in proton-proton collision

If we look at ion-ion collisions one can represent most observables as a function of centrality (0-5% centrality class event etc.). Is there any possibility to introduce centrality analogue in ...
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Deuteron wave function

The deuteron wave function is given by $$|\psi _d\rangle = a|^3S_1\rangle+b|^3D_1\rangle$$ where all states are normalized. How do we find $b^2$ s.t. the wave function reproduces the magnetic moment ...
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Is it correct that whenever energy change, mass also change?

Can I simply claim that, according to the mass-energy equation $E=mc^2$, whenever the energy of an physical object (not necessarily a microcosmic one) changes, its mass also change? Okay, I ...
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Estimate the moment of inertia of nucleus [closed]

How do I estimate the moment of inertia of the rotating nucleus, $^{232}_{90}Th$, using the first order estimate assuming the nucleus does not change shape at high rotational angular momentum? Can you ...
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22 views

Free energy for a nucleus

What is the physical significance of Free energy F? Why do sometime we calculate Free energy instead binding energy for a nucleus? If free energy is minimum at a certain temperature, then can we say, ...
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63 views

Isotope with longest decay chain to reach a stable isotope

Which decay chain of a radioactive isotope has the most 'steps' before reaching a stable isotope, i.e. decays into the most other isotopes before becoming stable?
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27 views

Complex structures bound by nuclear forces ( nuclear molecules ?)

This is very hypothetical question. Consider all chemistry (even bio-chemistry) is just physics of valence electrons. Because solutions of Schroedinger equation for system of electrons and nuclei are ...
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Nuclear fusion ignited by neutron capture

Does anybody know if there was some attempt to make a hydrogen (fusion) bomb using neutrons released from the fission primary? e.g. using $^{10}\text{B}$ hydrate as a fuel? Assuming reaction ...
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Why ingoing and outgoing impact parameters equal in elastic scattering?

Take the Rutherford scattering, as for example in this picture: What is the easiest way to show that the impact parameter "b" (see picture) is the same for the ingoing and outgoing trajectories? ...
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Underwater nuke - why does the shock wave first become visible at the top of the plume?

Seen at 0:30 seconds in, this video of Operation Crossroads Baker nuclear test the condensation behind the shock wave seem to become visible initially at the top of the plume - why?