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

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Peak in continous energy spectrum

I was reading online about particle decay. For the decay of Strontium-90 to Yttrium-90, a beta particle is emitted. The energy distribution of beta particle is continuous. If I know that the maximum ...
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36 views

What is the relation between Nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR)? [duplicate]

It seems to me that the basic principles are exactly the same, right? Then I am puzzled that the former was awarded a nobel prize while the later not. I noticed a similar question here What's the ...
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2answers
2k views

How to detect a secret nuclear detonation here on the earth?

How can we know that North Korea and Iran (to name a few) are exploding nuclear weapons if no inspectors have ever been granted access to suspected nuclear sites in these countries? How can we ...
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2answers
34 views

Nuclear transmutation of radioactive waste using high-energy neutrons

How likely does this work: Accelerate neutrons to as high energy as possible (particle accelerators/ cosmic rays ...) and hit (small samples of) our radioactive waste with it such that it is converted ...
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1answer
46 views

Physical meaning of parity in nuclear decays

I think it has to do with asymmetry in direction during emission of decay products .also what is implied physically when we say parity is violated in beta decays? I cannot imagine 'l' having an odd ...
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1answer
141 views

Parkhomov's E-cat reproduction [closed]

In the beginning of the year, Professor Alexander Parkhomov of Lomonosov Moscow State University claimed to have replicated (as read in e.g. Wired) of the E-cat functioning, albeit with lower effect. ...
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2answers
312 views

Does the population of higher level s-shells affect the decay rate of alpha emitters?

Consider a nuclide like $\mathrm{^{232}Th}$, which has a half-life of 1.4e10 years and which decays by $\alpha$ decay to $\mathrm{^{228}Ra}$. Alpha decay is a quantum mechanical tunneling process in ...
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3answers
1k views

Is the direction of gamma-ray emission by a nucleus totally random?

Let's consider an excited nucleus emitting one gamma-ray (not cascade etc). Is the direction of gamma-ray emission completely random? In other words, is the probability to detect this gamma equal for ...
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3answers
1k views

Why not dilute radioactive waste?

Radioactive wastes are dangerous because unstable elements are too concentrated. Originally radioactive elements come from nature where they were very diluted and that's why they were secure. So why ...
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2answers
457 views

Gamma Ray LASER Theory and Technology

I am aware that a similar question has been asked by someone else in the past, but in a very general form. Due to the physics interest and technology, in this question I put emphasis on the detail of ...
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4answers
78 views

Change in the half-life of a neutron

What would happen if the half-life of a neutron was much more less than it is now? How could this affect the nuclei?
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6answers
2k views

How many times has the “stuff” in our solar system been recycled from previous stars?

Is there a cosmologist in the house? I've got a basic understanding (with some degree of error) of some simple facts: The Universe is a little over 13 billion years old. Our galaxy is almost that ...
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340 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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17 views

Beta Decay: Fermi and Gamov-Teller decays for Neutron - >Proton Decay. Both are possible?

So I've been reading this textbook that says a decay from Neutron to Proton is $n$ -> $ p $ gives a $\frac{1}{2}^{+}$ -> $\frac{1}{2}^{+} $ decay This is corresponds to $\triangle I=0$ which is a ...
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3answers
3k views

Why can't Iron fusion occur in stars?

It is said that iron fusion is endothermic and star can't sustain this kind of fusion (not until it goes supernova). However star is constantly releasing energy from fusion of elements like Hydrogen ...
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2answers
2k views

How did Enrico Fermi calculate the classical Fermi Problem?

From Wikipedia: Fermi was known for his ability to make good approximate calculations with little or no actual data, hence the name. One example is his estimate of the strength of the atomic bomb ...
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3answers
358 views

Does water absorb neutrons?

Water is used as a shielding material in nuclear reactors. What's its function as a shield? Does it absorb neutrons and is there a reaction between water and neutrons?
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3answers
7k views

Origin of elements heavier than Iron (Fe)

In all the discussions about how the heavy elements in the universe are forged in the guts of stars and especially during a stars death, I usually hear that once the star begins fusing lighter atoms ...
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1answer
109 views

Can energy be weighed?

The binding energy of nucleus is calculated as- Mass defect = (Total mass of nucleons-Mass of the nucleus) And after that $E=mc^2$ is used for calculating the binding energy. Hot water is heavier ...
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40 views

Nuclear Fusion using magnetic fields

I was wondering if you could use a very strong magnetic field to produce nuclear fusion. The basic idea is a spherical cavity containing Deuterium (and possibly tritium) nuclei whose walls will be ...
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1answer
276 views

Is the long range neutron-antineutron interaction repulsive or attractive?

I can model this interaction as Zee does in "Quantum field theory in a nutshell". In chapter I.4 section "from particle to force" he uses two delta functions for the source. The integral gives ...
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1answer
90 views

Why are Electromagnetism, Strong & Weak Nuclear and Gravitational Forces different?

If they are different then why the only thing that we 'see' in them, and that identifies them, the so called 'force' as we call and see it, is same among them all.
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1answer
127 views

Effects of massive magnetic field generated by operation of the large hadron collider?

I read an article about the CERN large hadron collider in which it talks about the magnetic field that is generated while the LHC is operating. A magnetic field more than 100,000 times more powerful ...
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1answer
95 views

Mass conservation during $\beta^+$ and $\beta^-$ decay?

During the above mentioned decays the following happens $$n\to p+e^{-} \ and \ p\to n+e^{+}$$ then i assumed that this implied $$m_n=m_p+m_{e^{-}} \ and \ m_p=m_n+m_{e^{+}}$$ but by adding both sides ...
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1answer
111 views

Why is this nuclear reaction $p\to n+e^++\nu$ forbidden for a free proton? [closed]

Why is this nuclear reaction forbiden for a free proton? $$p\to n+e^++\nu$$ Where $p$ is the proton, $n$ is a neutron, $e^+$ is a positron, and $\nu$ is a neutrino. What i´ve been thinking is because ...
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1answer
132 views

Does the mass of a nucleus increase when it is excited to higher energy levels

If we consider an atomic nucleus that is excited to a higher energy level. This maybe due to absorption of gamma for example or as a result of some other decay or interaction. Would the mass of that ...
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4answers
431 views

Radioactive decay - What mechanism decides when an unstable nucleus decays?

My first question on Stackexchange (if it is formatted wrong or something please tell me so I know in future) - here it is: Given an unstable nucleus (exactly which nucleus is not particularly ...
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1answer
34 views

How the number of binary collisions increases with centrality faster than the number of participant in heavy ion collisions?

How the number of binary collisions increases with centrality faster than the number of participant in heavy ion collisions at different particle colliders?
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58 views

Probe the nucleus by using high energy particles

Why alpha particles would give better resolution than protons moving at the same speed? Can it be explained by Heisenberg uncertainty?
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1answer
175 views

What happens to mass during beta decay?

Sorry for being ignorant, but I'm in high school and our chemistry teacher barely went over beta decay. I decided to do some research and learned that in β+ decay, positrons are emitted from protons ...
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4answers
120 views

Why can't a nuclear reactor be used as a rocket motor?

Nuclear fission, and potentially fusion, reactors generate vast amounts of energy, primarily as heat. What stops us from harnessing that energy to propel spacecraft at or above escape velocity from ...
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1answer
2k views

Absolute isotope activity in a nuclear fallout

I've seen nice graph showing relative activity of each isotope in Chernobyl fallout: Could anyone suggest similar graph or raw data but for absolute isotope activity for the case of nuclear ...
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17 views

Diffusion of magnetization (NMR)

In the context of MRI I'm trying to understand the mechanisms of magnetization diffusion. Consider a sample that is magnetized by an external magnetic field. We have displacement of magnetic moment ...
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2answers
69 views

Does chemical energy contribute to mass? [duplicate]

Does chemical energy contribute to the mass of an object? I don't mean the bond energy, but the possible energy that could be released (i.e. Does an atom of oxygen and a molecule of hydrogen (H2) have ...
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2k views

Why is boron so good at neutron absorption?

Why is boron so good at absorbing neutrons? Why does it have such a large target area compared to the size of its nucleus?
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2answers
166 views

In a nuclear reaction, where does the energy go?

Lets say two hydrogen fuse together, where does the energy released go? Is it carried away as momentum imparted on the helium atom? Is it carried away in neutrinos? Is it carried away as gamma rays? ...
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1answer
198 views

nuclear physics- Energetics and Mechanics of Nuclear Reaction Homework [closed]

A sample of $^{24}_{12}\mathrm{Mg}$ is bombarded by a monoenergetic proton. If the resulting nucleus in a $^{24}_{12}\mathrm{Mg}(p,\gamma)$ reaction; $^{24}_{12}\mathrm{Mg}(p,\gamma)$ has its ...
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1answer
167 views

Mass loss for Fusion energy? [closed]

I am thinking how you can estimate the mass loss of the fusion energy for 1 kWh. I think you cannot use Einstein's $E=mc^2$ to calculate the mass loss in the fusion reaction of the Sun. How can ...
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2answers
282 views

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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1answer
56 views

Characteristic Ka X-rays [closed]

In an experiment one observes the characteristic Ka X-rays of two elements at energies of 6.930 and 7.478 eV. The higher energy line is due to Ni. What element is responsible for the lower energy ...
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40 views

Meaning of 'nuclear surface vibrations'?

Would like to know the meaning of nuclear surface vibrations as mentioned by Bohr in his paper titled 'The coupling of nuclear surface vibrations to the motion of individual nucleons'. The paper talks ...
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52 views

Positive/negative octupole moment of nuclei?

Does octupole moment of nuclear charge distribution show any positive/negative character, like the quadrupole moment does? Quadrupole moment has prolate and oblate types, but what about ...
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1answer
144 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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5answers
10k views

How do control rods work?

I understand the basic idea of nuclear fission: put a bunch of fissionable material together and let the neutrons fly. An atom gets split, kicking out a few more neutrons, which split other atoms, ...
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2answers
149 views

Why do heavy nuclei have half lives

Why do heavy nuclei have half-lives if they are unstable why do they take millions of years to break down in some cases why don't they simple do it instantly? What makes them stay together?
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90 views

Relationship between time, separation and neutron transfer probability?

As an ansatz, suppose we know that when a smaller nucleus is incident upon a larger one with 1 MeV of kinetic energy, there is a nontrivial probability that a neutron will tunnel from the smaller to ...
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2answers
148 views

Could I turn into a nuclear bomb?

Just out of curiousity, could the nuclei of our atoms split via quantum tunnelling, thereby leading to nuclear reactions and ultimately turning us into atomic bombs? I know that this is ...
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2answers
19 views

What combination of stable GE isotopes make up the germanium in a Ge(Li) spectrometer

I work with a Ge(Li) gamma spectrometer. I'm trying to work out the different populations of stable Germanium isotopes in it. I'm trying to model the unrealistic scenario where none of these isotopes ...
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Modelling populations of GE isotopes

I asked a question similar to this here: What combination of stable GE isotopes make up the germanium in a Ge(Li) spectrometer And got some very good answers. This question is instead based on the ...
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1answer
634 views

Why can't electrons be found inside the nucleus if there are infinite number of orbitals?

If there are an infinite number of orbitals, we can assume, that they can be present in any point in space. If that is correct, why do we not find electrons in the nucleus? I study in high school. ...