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

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126 views

Energy balance for beta decay of cobalt-60

I am confused by a simple fact about the $\beta^{-}$ decay of ${}^{60}{\rm Co}$ nucleus. According to Wikipedia, the most likely decay branch is to an excited state of ${}^{60}{\rm Ni}$, see the ...
7
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2answers
661 views

When did the first carbon atom in the Universe come into existence?

I am a chemist with a passion for astrophysics and particle physics, and one of the most marvellous things I have learned in my life is the process of stellar nucleosynthesis. It saddens me how my ...
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2answers
713 views

NMR Analysis of Ethylene glycol [closed]

I have the spectrum obtained by an NMR analysis of Ethylene glycol : I would like to explain the number of peaks in this spectrum, and assign them to the proton spins present in the molecule. I ...
3
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2answers
213 views

How clean will first generation fusion reactors be compared to fission reactors?

Googling the topic seems to indicate that fusion reactors will produce less waste and less toxic radioactivity, but this fact never seems to be mentioned during the current debate over nuclear power. ...
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1answer
213 views

Neutron-Antineutron creation/annihilation data

What is the most precise data for neutron-antineutron production by one photon (hitting a target in the laboratory system)? and/or What is the most precise data for neutron-antineutron annihilation ...
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1answer
319 views

correct formula for Mass Defect / Binding Energy? [closed]

I'm a web developer and I have to change an online course. The course teaches Advanced Nuclear Theory. In the 'Mass Defect and Binding Energy' chapter, it has this formula: $ \Delta M = Z(m_p) + ...
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1answer
34 views

Internuclear Binding Force: Experimental geometric detail

I am looking for the most precise currently available deuterium potential energy curve (generated purely by experimental data) on the nucleon-nucleon scale. This is crucial. I need a radial ...
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0answers
31 views

Conversion from Curies to current of alpha particles

Is the following conversion correct from microCuries to Amperes? $\mu Ci=(1$x$10^{-6}Ci)$ x $(\frac{3.7x 10^{10}Bq}{Ci})$ x $(\frac{2e}{\alpha})$ x $(\frac{C}{e})$ Becquerels are $\frac{decays}{s}$ ...
3
votes
1answer
64 views

pp chain gamma decay / intermediate state

Based on the first equation at http://en.wikipedia.org/wiki/Proton%E2%80%93proton_chain_reaction $$_1^{1}H+_1^{1}H \to _2^{2}He+\gamma$$ Is it correct to say that in the P-P chain two hydrogen atoms ...
0
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1answer
50 views

Algorithm for distribution of radiation

Unstable atomic nuclei will spontaneously decompose to form nuclei with a higher stability. What is the algorithm for deciding what sort of it is? (alpha, beta, gamma, etc. Also, given that alpha and ...
1
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1answer
80 views

Use of fission products for electricity generation

Why can't we use fissions products for electricity production ? As far has I know fissions products from current nuclear power plants create enough 'waste' heat to boil water; and temperature ...
2
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0answers
59 views

Proton as superposition of hadrons: $\vert p\rangle = c_0\vert p_0\rangle+c_1\vert h\rangle+\cdots$

I have a question regarding hadron fluctuations. For instance on page 85 in Feynman's "Photon-Hadron Interactions" equation 15.2 reads: $$\tag1\vert \omega\rangle = \vert ...
2
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1answer
65 views

Characteristic x-ray in energy spectrum

Context: Monte Carlo simulation of a linear accelerator photon beam. The energy spectrum for photons as calculated from the phase space files found in here has a peak somewhere near ...
1
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1answer
61 views

Why does Se-82 undergo double beta decay?

Looking at the decay chain, I saw it undergoes double beta decay. How is it feasible for something to undergo a simultaneous double decay?
3
votes
1answer
66 views

What decides fission products?

I am learning about nuclear fissions and learned about the fission fragment distribution. It was interesting to see that the fission fragments have unequal masses. I was wondering as to what governs ...
1
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1answer
545 views

saturation property of nuclear forces ? and its relation binding energy per nucleon constantcy?

Please explain why binding energy per nucleon is constant(pratically) for atomic number, A, larger than 30 and less than 170, and explain the saturation property of nuclear forces with analogy that ...
-4
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1answer
163 views

How can I destroy earth with physics? [closed]

I want to destroy the whole earth using physics, I would like to learn some of the ways that can be used to achieve this. I tried using a nuclear bomb but it takes so long, and I can't wait that much: ...
6
votes
1answer
433 views

What is the most stable nuclide of an isobar?

From the semi-empirical mass formula, the mass of an atomic nucleus is $$M\left(A,Z\right)=Zm_p+(A-Z)m_n-\frac{E_b(A,Z)}{c^2}$$ I've been told (at first) that for a given mass number $A$, the most ...
4
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1answer
193 views

What does the Coulomb barrier really mean?

I realize I'm trying to get a simple answer on a complicated subject, but here goes anyway. I've done some research and I understand (well, mostly) about how Vc is the amount of energy required to get ...
0
votes
1answer
119 views

What is the theoretical wattage output of a Tokamak fusion reactor?

By that I mean the complete radiative wattage of any type of energetic radioactivity or electromagnetic wave or even particle if that's what they output. My purpose is to compare this to the suns ...
0
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2answers
84 views

It's possible to create a proton colliding a positron with enough energetic photons?

If a proton is supposed to decay in a positron and gamma ray photons is possible to obtain the opposite process colliding enough energetic photons with a positron and create a proton ?
1
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1answer
820 views

Ba K Lines in a Cs-137 gamma ray spectrum

I'm looking at a spectrum for the gamma ray spectrum of a 137-Cs source and I'm not sure where the peak in the lower energies of ~32keV comes from. I understand that it's to do with some sort of ...
3
votes
1answer
171 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 ...
4
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2answers
423 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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0answers
58 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?
4
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1answer
56 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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0answers
112 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 ...
3
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0answers
49 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})\\ ...
2
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2answers
101 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 ...
2
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1answer
486 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
378 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 ...
1
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1answer
126 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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0answers
76 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 ...
2
votes
1answer
99 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 $l=1$). ...
0
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1answer
1k 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, ...
1
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1answer
187 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
130 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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1answer
52 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
480 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
573 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
72 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 ...
1
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1answer
150 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
votes
2answers
441 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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38 views
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2answers
86 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 ...
3
votes
1answer
225 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 ...
0
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0answers
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 ...
9
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2answers
266 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
93 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 ...