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

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154 views

Do atomic nuclei have fixed orientation and position with respect to the electron cloud?

Does the nucleus of an atom of any element (besides protium) maintain a particular orientation in relation to its electron cloud? Does it bounce around within its cloud? Can it be ejected from its ...
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346 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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50 views

Difference between RPA and generalized RPA

The random phase approximation (RPA) is an approximation method in condensed matter physics and in nuclear physics. What is the difference between RPA and generalized RPA?
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50 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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90 views

physical intuition behind quasi-bound state formation in feshbach resonance

In Feshbach resonance, by scattering theory formalism it is found that the resonance in cross-section happens when bound state energy of the closed channel is near to the scattering state energy of ...
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42 views

how is feshbach resonance potential term physically produced?

In Feshbach resonance model, a 2*2 potential term with space dependent diagonal and non-diagonal terms is written $\left(\begin{array}{cc} V_{11}(\mathbf{r}) & V_{12}(\mathbf{r})\\ ...
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2answers
74 views

Binding energy in fission

In nuclear fission the total rest mass of the products is less than the mass of the original nucleus. But on the other hand, the binding energy of the products is higher. Doesn't the decrease of the ...
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1answer
220 views

Parity of proton is 1?

I have found from Wikipedia that "a parity transformation is the flip in the sign of spatial coordinates". Now when we operate parity operator, does that mean we are taking any physical entity at ...
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2answers
163 views

binding energy of a nucleus is positive?

I have found from this link http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucbin.html that: Nuclei are made up of protons and neutron, but the mass of a nucleus is always less than the sum of the ...
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28 views

What jobs can you get in the field of physics? [duplicate]

What good, fun and reasonably well paid jobs can you get in the field of physics?
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1answer
95 views

Why does mass change in to energy during a nuclear change?

I have been doing some research on nuclear changes and I have found that the energy released during a nuclear change comes from a minuscule amount of mass that is converted in to energy. After making ...
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70 views

Formulas for mass of nucleus and atom. Looking for clarification

I've been searching the internet for a formula for nuclear mass which accounts for various interactions present. I've encountered the following formulas: $$m = Zm_p + (A-Z)m_n - \frac{B}{c^2}$$ $$m ...
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1answer
88 views

Angular momenta of photon

$A^\mu$ can have multipole expansions in classical electrodynamics. This gives rise to dipole photon, quadrupole photon etc. For dipole photon $j=1$ (In electrodynamics books they write it as $l=1$). ...
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1answer
688 views

Potential energy of the human body if all its atoms were split

I am working on a sci-fi story in which a character has control over matter on the atomic level (think Dr. Manhattan from Watchmen). In thinking up potential tragedies for this character I thought, ...
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1answer
90 views

Temperature Dependence of Fission

I've always heard fusion depends on incredible temperatures and pressures, but I'm curious what the temperature dependence of fission is. For instance, if I had uranium and heated it to a ...
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1answer
96 views

Ground State Assignment for nuclear shell model

Why is the ground state assignment $0^{+}$ whenever the number of neutrons and protons are both even?
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49 views

$α$-decay and electron

I'm a Web developer and I'm working on a physic interactive Web page to represent how atoms interact. I'm reading information about α-decay and here is what I understand. Let's say we have a isotope ...
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2answers
228 views

Formula for critical mass? Critical mass of polonium?

I'm looking for the critical mass of Polonium; is there a formula? E.g.:$$\text{Neutrons / Protons}\cdot\text{ Constant = X kg}$$ There is a little table in the Wikipedia. E.g.: ...
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2answers
258 views

Does the fact that protons and neutrons have larger mass than electrons mean they're bigger in size?

and so if a proton is so larger than an electron doesn't that mean it has a shape? What would be the shape of a subatomic particle? are they spherical?
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1answer
46 views

Nuclear forces and Chiral Effective field Theory

I am new to this field "nuclear forces and Chiral Effective field Theory". while reading this paper http://arxiv.org/abs/nucl-th/0006014 . I have got few question: How many different version of ...
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1answer
104 views

Coupling of open and closed channels in Feshbach resonance model

Feshbach resonance is described with coupling of 2 systems differing in the form of potentials :- one is said to produce a bound state (in 'closed' channel) and other is to produce scattering states ...
2
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2answers
280 views

Measuring background radiation

We tried to measure background radiation using a geiger counter for a experiment at school. The meter showed $0.12$-$0.21$ microSv/h during the day averaging at about $0.14$ mcSv/h. As we tried to ...
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30 views
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2answers
77 views

What causes different decays?

Nuclei spontaneously decay according to a certain decay rate. There are however different kinds of decay, alpha, beta, gamma... What causes then the nuclei, when they decay, to do so in one way of ...
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1answer
147 views

What determines the distribution of the energy between the beta-particle and the neutrino in beta decay?

When beta-decay occurs an electron or a positron is emitted along a neutrino or an antineutrino. The energy spectrum of the beta particles is continuous because, as I read, the energy is shared ...
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1answer
43 views

Different kinds of the same isotope

I apologize if this is an obvious question, but I can't find the answer anywhere. In this page: http://ie.lbl.gov/education/parent/U_iso.htm are listed the isotopes of Uranium. Some of them, for ...
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0answers
12 views

What are the coefficients of the Geiger-Nutall law dependent on?

The Geiger-Nutall law for alpha-particles predicts a linear relationship between the logarithm of the decay rate and the energy of the particle, and I've observed that in ln(decay rate) / (energy) ...
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25 views

Origin of the names for the decay chains

Is there any reason for the names of the decay chains? As shown in this chart (larger version here): only the Thorium chain starts on an isotope of the element it takes its name from, and it can ...
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2answers
239 views

The life of proton

I have two questions regarding protons 1) Wikipedia says Mean lifetime of a proton $>2.1×10^{29}$ years (stable) Obviously this means practically nothing happens to a proton, but what does ...
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1answer
86 views

What is the state of the art in particle detection and localization

I am researching methods to detect the position of radioactive materials (emitting gamma and beta particles), and would like to know what current methods are used to do this. What type of sensors are ...
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2answers
195 views

How Does Lead Block Radiation

How is it that lead can block radiation, and things are lead lined. In the Indiana Jones 4 movie he climbs inside a lead-lined fridge and he somehow survives the blast and radiation?
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4answers
304 views

Is it possible to split baryons and extract useable energy out of it?

Since baryons (e.g. protons, neutrons) are composite particles it should be possible to split them apart. If so, is it then possible to extract useable energy out of the splitting of baryons in ...
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0answers
28 views

Troubles with the Nucleon Bound Energies

I was reading my quantum mechanics text and I have a doubt. I have the energy levels well defined for the finite square well and the author suddenly compares (I believe) those levels with the levels ...
4
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1answer
156 views

Is a Betelgeuse supernova able to neutralise earth's nuclear arsenal?

According to an article on newscientist.com, a neutrino beam could neutralise nuclear bombs by inducing a slow meltdown of the nuclear fuel. The neutrino generator would need to be more than a ...
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How can a proton be converted to a neutron via positron emission and yet gain mass?

The mass of a neutron is greater than mass of a proton so how is it possible in positron emission for a proton to form a neutron and a positron?
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1answer
84 views

Is it possible to calculate the half-life of a nucleus?

Is it possible to calculate theoretically the half life of a nucleus (how?) or they are all known through measurements? As an example how do you calculate the half life of Carbon-14?
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51 views

Does the spinning of a nucleus alter its charge distribution?

I put a nucleus in a magnetic field. It spins. Does the electric charge distribution remain homogeneous or does the charge redistribute? Can this be measured? Will accept reference as answer.
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100 views

Geometric quantization AND nuclear physics

Classical mechanics has a natural mathematical setting in symplectic geometry and it may be asked if the same is true for quantum mechanics. Geometric quantization is one formalization of the notion ...
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1answer
103 views

Proof of Bethe-Bloch stopping power

I want to prove the Bethe-Bloch stopping power formula but I don't know where to start. Any one can offer a book or paper? Related: http://en.wikipedia.org/wiki/Bethe_formula
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1answer
472 views

Nuclear Spin of Sodium 23

I am actually calculating the nuclear spin of Sodium 23. Here we have 11 protons and 12 neutrons. Now both the nuclei are short of the magic numbers. When I use the shell model for protons and ...
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0answers
27 views

Geometric structure of atomic nucleus? [duplicate]

The electrons in an atom have a certain configuration and we can predict in which space the electrons can be present of a certain energy level (s-orbitals have a sphere-shape,....). Recently I read ...
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1answer
107 views

Nuclear fission or fusion occurring at or near the speed of light

Suppose a device or object were traveling at or near the speed of light, and fission or fusion occurred while in this state of motion, creating an enormous blast, what would occur? Would this cause an ...
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1answer
261 views

Centrality and collision parameter b

Can someone tell me what does it 20-30% collision centrality mean in terms of impact parameter b?
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1answer
267 views

Radioactive decay / binding energies

If my understanding is correct, the binding energy determines a nucleus' stability and the greater the binding energy, the more stable the nucleus (e.g iron-56). The mass of the sum of nucleons that ...
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1answer
152 views

What is Rabi nutation in NMR?

What is the mathematical and physical significance of Rabi Nutation in terms of NMR?
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1answer
134 views

Does the Strong Nuclear Force follow Superposition?

I have just started the study of nuclear physics in my high school, and while reading about nuclear forces and binding energy per nucleon, I found out that the nuclear forces are highly short ranged ...
4
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1answer
51 views

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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1answer
2k views

What prevents an atom's electrons from “collapsing” onto its protons? [duplicate]

Forgive me if the answer to this is obvious. I have no formal physics training, and I remember that when I asked my physics teacher this, she just frowned and said "Good question." An electron is ...
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1answer
66 views

4 element super conductor without oxygen and iron

I am trying to find a list with super conductors. In particular I am searching for a superconductor, that consists of 4 elements none of which is Oxygen. The reason I rejected Oxygen, is because(from ...
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0answers
79 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 ...