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

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Unknown peaks on RBS spectrum

I was given a sample, that it is supposed to be a medium thickness Rhodium on top of an infinite silicon waffer. The experimental RBS spectrum along with the simulation looks like that Apparently, ...
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76 views

How to describe hadron-hadron strong interactions from QCD?

I'm trying to set up the problem of deriving the thermodynamics of hadronic matter. I know how to proceed in the case of an effective description such as mean field (Walecka/linear sigma model) but ...
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199 views

Nuclear physics from perturbative QFT

Is there a renormalizable QFT that can produce a reasonably accurate description of nuclear physics in perturbation theory? Obviously the Standard Model cannot since QCD is strongly coupled at nuclear ...
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88 views

Problem with shell model and magnetic moment of Lithium-6

I have a problem with the calculus of magnetic moment of Li-6. The configuration of protons is $1p_{3/2}$, and the neutrons' one is the same. I have to add the magnetic moment of uncoupled proton ...
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462 views

How do we know that the nucleus isn't a quark-gluon plasma?

The standard picture of the nucleus of atom is that is several distinct nucleons, which themselves are composed of quarks. However, it seems to me like a much simpler picture is that the nucleus is ...
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71 views

Why is binding energy $\Delta mc^2$?

As we know the mass-energy equivalence relation $E=mc^2$ originally came from special relativity. And the binding energy is $\Delta mc^2$. How do we know that the extra mass coming from theoretical ...
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86 views

Why does the Walecka model not include pions?

The Walecka or $\sigma$/$\omega$-model is an effective theory describing nucleon-nucleon interaction by an exchange of $\sigma$/$\omega$-mesons. Why does it not include interactions by pions?
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53 views

Copper coils for nMRI

Given the lack of financial efficacy in the medical industry, I was wondering if nuclear magnetic resonance imaging would be possible with a copper/silver coil if the use is short 10 second imaging ...
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10k views

Why do electrons occupy the space around nuclei, and not collide with them?

We all learn in grade school that electrons are negatively-charged particles that inhabit the space around the nucleus of an atom, that protons are positively-charged and are embedded within the ...
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149 views

How is North Korea planning to test a nuclear device underground? [closed]

I am reading the news about North Korea planning to test a nuclear device underground, and while fascinating, I have no idea what this phrase actually means. Could somebody explain, in absolute ...
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1answer
19 views

What is the distribution of energy between the alpha, beta and gamma particles emitted in nuclear fallout per one RAD?

I have been trying to find a relation to be able to convert from RAD to REM. What I found is that I need to know the "quality factor" as some sources call it, which is the effect of different ionizing ...
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17 views

Critical size and Radioactive Nuclei

Nuclear fission requires the mass of the fissile material above the critical mass. So that the explosion takes place at least in the case of a nuclear bomb. But once a single nucleus got involved in ...
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546 views

Long time deviations from exponential decay in radioactivity

Are there any examples of common substances whose decay is not exponential? We're used to thinking about radioactivity in terms of half-lives. This is a concept that makes sense only for a decay that ...
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48 views

Why is Silver-108 unstable

Why is Silver-108 unstable if silver-107 and silver-109 are stable? I found it on crash course but no answer was given.
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1answer
77 views

What causes radioactivity? Is it a quantum mechanical effect?

I'm just curious what causes radioactivity. I've been told that in the case of alpha decay, since the nucleus is quantum mechanical, there is a probability that the configuration of protons and ...
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1answer
36 views

Which nucleus is the most resilient against gamma-induced fission?

To state the title question perhaps more precisely: What is the largest photon energy $E_{\gamma}$ and the corresponding mass number $A$ and atomic number $Z$ of a suitable nucleus ${}^A_ZX$ ...
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Why can Hiroshima be inhabited when Chernobyl cannot?

There was an atomic bomb dropped in Hiroshima, but today there are residents in Hiroshima. However, in Chernobyl, where there was a nuclear reactor meltdown, there are no residents living today (or ...
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39 views

Strength of strong nuclear force vs distance?

Is there at least an approximation of the decrease in strong nuclear attraction vs distance from the center of the nucleus?
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101 views

How do substances with like charges repel each other?

I have read in a number of places how substances with opposite charges attract each other: The excess electrons in the one substance repels the electrons in the other substance so that they move away ...
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145 views

Spallation neutron generation and pure U-238 reactors

Main question: Is it possible to achieve net power generation based on linear proton accelerator and U-238 target? In the proposed reactor design there is a proton beam with energy ~10 GeV, and on ...
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757 views

Why did nuclear testing not result in nuclear winter?

According to Wikipedia over 2000 nuclear tests have been performed since the Manhattan Project. If nuclear war would bring about a nuclear winter, why didn't testing do? Were they too much spread out ...
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269 views

Why doesn't a nuclear fuel pool become irradiated?

Why doesn't the volume of water in a nuclear fuel pool become irradiated? Why wouldn't the water around the pool become radioactive and circulate around making the whole thing deadly? My question ...
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28 views

Blazars and nuclear physics!

How are studies on blazars related to the field of nuclear physics? Should these not purely belong to Astrophysics? Just inquisitive.
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41 views

Are there any established theories as to why dubnium-268 and 270 have such high stability for a trans-actinide?

Dubnium-268 has a half life of 29h and 270, 23.15h. I know of the island of stability but if dubnium is in it, the island is very small as only rutherfordium has isotopes that approach the same ...
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56 views

Is fission reaction considered natural or artificial? [closed]

As I learned, nuclear fission doesn't occur without the control of a human made nuclear reactor, by hitting a neutron to a fissile isotope. Thus, the fission reaction is considedred as a part of ...
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262 views

Coordinate system

Quoting from 'Nuclear Physics - Theory and Experiment' by RR Roy, BP Nigam 2005 edition Link to text How did the author arrive at equations (23a, 23b,23c)? Chapter 8 Nuclear model II, 8.7 ...
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45 views

Does Uranium-235 always split into Krypton and Barium in nuclear fission?

In most nuclear fission examples and exercises, the products of a nuclear fission of Uranium-235 are two light nuclei of Krypton and Barium: $$\mathrm{ _0^1n + U \longmapsto Kr + Ba + energy }$$ Is ...
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72 views

Is there still mystery about spin crisis?

The gluon is a vector boson; like the photon, it has a spin of 1. If this is true and if we know the spin of protons and neutrons then why the news SPIN COMES FROM GLUONS? is telling that, we ...
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104 views

Why do almost all nuclear reactions release energy?

I'm just wondering why almost all nuclear reactions release energy, in a typical way, the mass defect is transformed into energy ? Is there a nuclear reaction that gains mass (resp. energy)? or most ...
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93 views

Why is the spectrum of the $\beta$-decay continuous?

the spectrum of the Gamma and Alpha decays are both discrete, i.e. the $\alpha$-particles and the $\gamma$-rays take on only discrete values when emitted from a decaying nucleus. Why is it then, that ...
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Why is beta negative decay more common than beta positive?

In simple terms, why is beta negative decay more common than beta positive? I know it's something to do with occuring inside/outside the nucleus - but I can't find a simple, easy to understand ...
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55 views

Shell model of an odd-odd nucleus: $^6$Li

Lithium-6 isotope has an approximate magnetic momentum of $0.88\ \mu_N$ in its fundamental nuclear state. I'm trying to find its angular momentum and parity. I found in a standard table: $I=1^+$ and ...
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29 views

Thorium based nuclear reactor [closed]

My question is how thorium works as a radioactive nuclear fuel and what are the special properties of thorium based nuclear reactor.
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229 views

About mass defect

Here's how my book explains mass defect: Particles inside the nucleus interact with each other - they feel attraction. The potential energy $U$ of such attraction is negative, because in absence ...
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22 views

Nuclear Compton Scattering Data

Is there a repository where one can find unpolarized nuclear Compton scattering data $\gamma (Z,N)\rightarrow \gamma (Z,N)$ for specific nuclei $(Z,N)$? or even some parametrization of structure ...
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Would it be possible to detect nuclear explosion on exoplanet?

How strong would have to be nuclear explosion on exo-planet that orbits some other star for it to be detectable outside of that system. Or it would be impossible due to amount of radiation coming from ...
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25 views

Nuclear explosion wavelength data

I am looking for data source (or chart) of spectral data that is being emitted on detonation of nuclear or thermonuclear explosion. Reason I am looking is to see if this data has specific signature ...
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40 views

Explosive energy in a container [closed]

What happens when the explosive energy of a grenade or a bomb is contained in a container, if you will, and no energy can be released through the container in the form of heat or sound etc...? Just ...
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480 views

Would being underwater help survive a nuclear bomb?

If I jump in my pool, on the river near my house knowing that a nuclear bomb, or atomic or H-Bomb exploded around 10 km from my house, would I survive? The way I see it is that water will protect me ...
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44 views

Parity of a system composed of 2 particles

I have read that for a system of 2 particles, the total parity is given by: $P=P_1 P_2 (-1)^L$ where $ P_1, P_2$= insisec parity of particle 1, 2 $L$ = relative angular moment what's the meaning ...
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27 views

Could someone explain the “revolving frame” to me, as it is used in basic NMR?

I am an undergrad intern at a national lab currently working with a basic proton NMR device. The device consists of two big coils which provide the static magnetic field, and a smaller coil, which ...
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56 views

Radioactive decay law and the exponential model, is it always valid?

The law of radioactive decay reads $$ N(t)=N_0e^{-\lambda t}$$ Is it valid when there is less than 1 nucleus or particle to decay? Obviously, it is nonsense to consider that we have 1/2 of nucleus ...
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Is the half-life of Primordial Nuclide determine only by the age of the earth? [closed]

Is the half-life of Primordial Nuclide determined only by the age of the earth? Or are their other age defining considerations? The point of the question is to know that the only reason that we have a ...
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255 views

Why does the addition of paramagnetic ions decrease the spin lattice relaxation time of protons?

My question pertains to NMR (nuclear magnetic resonance). $T_1$, the spin lattice relaxation time of protons in water is about 2.5 seconds. If you add some $CuSO_4$ (copper sulfate) to the water the ...
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36 views

Totally antisymetric wavefunction: clarification about terminology

Pauli's Principle says: "The wavefunction of two identical fermions must be totally antisymmetric". I know that, for a antisymmetric wavefunction, $(-1)^L*(-1)^{S+1}*(-1)^{I+1}=-1$ "totally ...
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66 views

What makes nuclear binding energy so much stronger than chemical energy

The strong force acting between quarks and responsible for holding protons together is 100 times stronger than the electromagnetic force. How come the nuclear binding energy derived from the strong ...
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1answer
25 views

Collision of a heavy charged particle with an electron at rest - Deduction

When I was studying Nuclear Physics I saw this formula about interaction of radiation with matter. The book mentioned that when considering a elastic collision of a heavy charged particle of mass $M$ ...
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545 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 ...
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Why do all elements above $\require{mhchem}\ce{Fe}$ not decay to $\ce{Fe}$?

OK, so $\ce{Fe}$ is the most 'stable element'. As such, why do all elements above it not decay into $\ce{Fe}$? In all cases, would it not lead to an increase in binding energy and therefore energy ...
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Nuclear Physics: Eigenvalues of nucleus angular moment

In the shell model of nuclei, when we talk about collective motions, we describe any nucleus deformation, expanding its radius on spherical harmonics base like this $R(\theta,\phi) = ...