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

learn more… | top users | synonyms (2)

3
votes
2answers
409 views

How much radiation exposure in the US was caused by the 105 nuke tests in the Pacific?

Between 1947 and 1962 the US conducted 105 tests of nuclear weapons in the "Pacific Proving Grounds". I'm wondering how much radiation exposure resulted on the west coast of the US. These were part of ...
3
votes
2answers
113 views

About Nuclear magnetic resonance

I'm trying to understand the basic principles of Nuclear Magnetic Resonance reading this link but I have some doubts: 1) I have ever known that when protons aren't in a magnetic field, their spins ...
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 ...
3
votes
2answers
563 views

Stable Nuclei - Deviation from equal protons and neutrons

While studying the semi-empirical mass formula for nuclei, I came across an "asymmetry term" whose function, as far as I understand, is to build in the fact that nuclei "prefer" to have equal numbers ...
3
votes
1answer
434 views

Should the expression for energy conservation in alpha decay include the mass of electrons?

Let $M_P$, $M_d$, $m_\alpha$, $m_e$ and $Q$ the mass of the parent nucleus, daughter nucleus, alpha particle, electron and the disintegration energy, respectively. I understand that applying ...
3
votes
1answer
67 views

The synthesis of $^{254}\text{No}$

How is $^{254}\text{No}$ synthesised? Could you explain the reaction where it is preceded by $^{208}\text{Pb}(^{48}\text{Ca}, 2\text{n})$? References to articles are well enough—I was somehow unable ...
3
votes
1answer
689 views

What is the relationship between earthquakes power and nuclear explosions?

What is the relationship between earthquakes power and nuclear explosions? How to compared power of earthquake with nuclear explosion?
3
votes
1answer
244 views

How do people get the proton number for each element from experiment?

How did people determine the proton number for each element from experiment in each decade of 20th century?
3
votes
3answers
1k views

Does the Breit Wigner formula apply to intermediate virtual particles?

Breit Wigner Formula describes the cross section for interactions that proceed dominantly via a intermediate particle (O*) A+B → O* → C + D: $$σ = \frac{2\Pi}{k^{2}}\frac{Γ_{i}Γ_{f}}{(E-E_{o})^{2} + ...
3
votes
3answers
257 views

Ratio of radiation sources in the uranium cycle

Sorry, I know y'all are probably getting a lot of questions re: Fukushima, but I had a very specific one and no-one has been able to answer it. I am specialised in medical radiation, and have been ...
3
votes
1answer
44 views

What does 'channel' mean?

I see many plots like the following that graph counts per channel, I know what a 'count' is, but I don't know what a 'channel' is. Could somebody please explain to me? My guess is that it is that ...
3
votes
1answer
69 views

What is relationship between Quantum tunnelling and Gravitational potential energy of stars?

Are there a direct mathematical relationship between Quantum tunnelling and Gravitational potential energy of stars? The true source of the Sun's energy was shown by Hans Bethe to be nuclear fusion ...
3
votes
3answers
527 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 ...
3
votes
2answers
2k 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 ...
3
votes
2answers
1k views

How is energy produced in Alpha emission (radioactivity)?

In the above Alpha decay reaction, we get thorium by the alpha decay of uranium with an alpha particle. But we also get energy of amount Q by this process. And according to my course books, this Q ...
3
votes
1answer
475 views

Theoretical power limit of nuclear bomb

Is there any limits of power or power to mass (or any other) limits for nuclear bombs? I found this wiki article: Nuclear weapon yield: Yield limits. Is the information provided is correct? If yes, ...
3
votes
1answer
463 views

“Dynamic Albedo of Neutrons” and all these Farnsworth fusors

I've checked specs of Russian "Dynamic Albedo of Neutrons" module on Mars MSL rover - it can do 10^8 neutron pulses at 10 pulses per second. It works on D-T reaction in tiny linear accelerator, and ...
3
votes
1answer
420 views

Phase space suppression

In talking about production/decay processes, I've heard people speaking of decay modes or cross sections being 'phase space' suppressed. For example, a two body final state is more likely to occur ...
3
votes
2answers
247 views

Pressures Necessary for Carbon Detonation

Carbon detonation is a characteristic event of Type 1a Supernova (EDIT: where an accreting white dwarf near the Chandrashankar limit of 1.4 solar masses explodes), an extremely important standard ...
3
votes
1answer
117 views

Proton-Neutron Lattice as a form of matter?

Would it be possible for a lattice of protons and neutrons (I'm picturing a plane of hexagons in my head) to exist bound by the strong nuclear force (not gravity)? I know that the strong force losses ...
3
votes
1answer
253 views

Can stable nuclei theoretically fission through quantum tunneling?

As I understand it, an unstable nucleus is going to randomly fission because the forces binding it together are momentarily weaker than the electrostatic repulsion of the protons. Given that some ...
3
votes
1answer
436 views

Why the pion does not get mass under Spontaneus breaking of chiral symmetry, but the quarks do?

Some sources state that when the mass of a quark goes to zero, it allows for Spontaneous Breaking of Chiral Symmetry and gets a constituent mass of about $200\, \mathrm{MeV}$. Other sources state ...
3
votes
3answers
592 views

If there is a meltdown at the Fukushima reactors, would the control rods melt also?

According to the reports, the shutdown procedures at all the Fukushima reactors were successful, and all the control rods were fully inserted. So - if there was a meltdown, would the control rods ...
3
votes
3answers
82 views

Why do nuclear weapons create a blast wave?

As far as I know, in a nuclear explosion the energy is released in the form of radiation (neutrons, gamma rays, alpha particles and electrons), light and heat. There isn't a chemical reaction that ...
3
votes
2answers
63 views

What's the slowest nuclear decay rate that's been measurably linked with a narrow energy linewidth?

As was explained in the question What is the relation between the half-time and the line-width of a radioactive nucleus?, the half-life $\tau$ of an unstable nucleus is related to the linewidth ...
3
votes
4answers
115 views

Can neutrons be synthesized purely from protons and electrons?

Can neutrons be synthesized purely from protons and electrons? Note: I'm looking for reactions that do not require neutrinos or any particles besides just protons and/or electrons as reactants.
3
votes
1answer
216 views

Why are atomic quadrupole moments calculated using nuclear spin?

It's my understanding that electric quadrupoles interact with the gradient of an electric field, and I understand roughly how this works. I am trying to calculate the interaction between an atomic ...
3
votes
1answer
138 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 ...
3
votes
1answer
99 views

Put yourself in the shoes of Wolfgang Pauli (1930): How could Pauli have narrowed the culprit down to one particle, instead of many?

A while ago, during my introductory physics course, my professor purposefully neglected to tell us about the existence of the anti-electron neutrino in beta decay; he made it an assignment(on our ...
3
votes
1answer
198 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 ...
3
votes
2answers
900 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 ...
3
votes
1answer
459 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 ...
3
votes
2answers
364 views

Proton-proton bound state

There is something unclear for me. We say that the deuterium is a proton-neutron bound state of orbital angular momentum L=0 and of total spin S=1. I don't understand why can't we build such a state ...
3
votes
1answer
381 views

Why is the total interaction cross section larger for incident particles with lower energy?

The cross section of a nuclear interaction is a measurement of the probability of that interaction occuring. These probabilities are typically presented in terms of barns ($10^{-28}$ m$^2$) as a ...
3
votes
1answer
237 views

The vacuum as trigger

Do the apperance in the atomic nucleus of virtual matter-antimatter particle pairs play a role in the random nature of radioactive decay?
3
votes
1answer
203 views

$\frac{1}{\sqrt{2}}$ (|Independent particle Model⟩+ |Strong Interaction Model⟩)?

What is an adequate way to understand this simultaneously. One has the underlying assumption that matter is saturated and has the merit of being able to come up with an accurate formula for the ...
3
votes
1answer
254 views

PNMR, Pulsed Nuclear Magnetic Resonance, Experiment

I am writing a lab report for class on PNMR experiment that we did. How come in this experiment we don't worry about the electron spins in our sample? Aren't the electrons affected by the PNMR machine ...
3
votes
1answer
116 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.
3
votes
1answer
173 views

Velocity distribution in ion source (electron bombardment) for Bainbridge mass spectrometer

Consider the following schematics of a Bainbridge mass spectrometer (Source: ...
3
votes
1answer
63 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 ...
3
votes
2answers
149 views

Can I excite an already unstable element for accelerated decay?

Say I had an unstable element ready to go through beta decay and I introduced it to high speed electrons: would this lessen the time needed for the product to go through beta decay?
3
votes
1answer
128 views

Containement system of a nuclear reactor: role of the water moderator

In a modern nuclear reactor for example a PWR there are multiple containment systems which prevent the release of radioactive material into the environment and shield the environment from the ...
3
votes
1answer
365 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 ...
3
votes
2answers
2k views

Why is the binding energy per nucleon not zero for hydrogen atom?

The lone proton has not to be worked on against any electrostatic force. So where does the energy come from? What is mass defect for a hydrogen nucleus?
3
votes
1answer
370 views

gamma ray lasers?

Is it really possible in the foreseeable future to create a gamma ray laser? I've read these two articles on Wikipedia: the Hafnium controversy Induced gamma emission It sounds pretty amazing, ...
3
votes
1answer
1k views

Decay of Cobalt-60 isotope

How does the Gamma decay of Cobalt-60 occur? Motivation: A research team led by D. Habs made contributions to our understanding of the gamma decay of Ca-40 and Zr-90: ...
3
votes
2answers
779 views

What are nuclear isomers? What is isomeric energy?

Can someone explain nuclear isomers to me, and in particular what the energy involved is? I understand generally that we're talking about moving from a less to more stable configuration of nuclear ...
3
votes
1answer
1k views

Why must the deuteron wavefunction be antisymmetric?

Wikipedia article on deuterium says this: The deuteron wavefunction must be antisymmetric if the isospin representation is used (since a proton and a neutron are not identical particles, ...
3
votes
0answers
26 views

Why is the nucleon axial charge a charge?

Lets take a look at the definition of the nucleon axial charge $g_A$ $\langle p|A^a_\mu|p\rangle = g_A \bar u(p)\gamma_\mu\gamma_5\tau^au(p)$ with the QCD axial current ...
3
votes
0answers
24 views

References or resource recommendation for the mathematics concerning fission

I am working on a statistical problem that appears similar (in some respects...) to nuclear fission. I am interested in the properties of a system undergoing fission around, or near, delayed ...