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19 views

Can neutrons detect the diamagnetic effects of superconductivity?

It is well known that an applied magnetic field to a superconducting material produces a diamagnetic response due to the induced screening currents. Neutrons used as a probe for magnetism and crystal ...
6
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1answer
70 views

Charge structure of the neutron

David Griffiths’ book on elementary particles says that the neutron is positive at the center and edges, negative in between. (Introduction to Elementary Particles, Wiley, 1987, p. 21). But Wikipedia ...
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2answers
56 views

Basics questions about the strong force

I have what is probably a bitter misconception about the strong force which I would like to clarify. Here's my (probably flawed) reasoning. The strong forces holds protons and neutrons together at ...
2
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1answer
49 views

Clebsch-Gordan Coefficients - Neutron can't decay into a proton and electron.

I've been reading in Weinberg's Lectures on Quantum Mechanics and in a note under the text it said that I can use the Clebsch-Gordan Coefficients to show that a neutron can't decay into a proton and ...
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2answers
54 views

Why don't the magnetic dipole moments in a neutron cancel out?

This may be a silly question. I thought magnetic dipoles were dependent on electric charge, so why in a neutron do the dipole moments not just cancel each other out?
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0answers
76 views

What is the cause of the minor mass difference between the proton and the neutron?

As known, the proton is from two up and a single down quark, while the neutron is from a single up and two down quarks. The down quark is a little bit more massive and the up, and so the neutron is ...
6
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1answer
131 views

Can coherent superpositions of a neutron and antineutron exist?

In my recent post I learned that electric charge is always conserved in contrast to strangeness quantum number, which limits the types of Hadrons that can be build. Furthermore, also different masses ...
3
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2answers
104 views

Did people ever thought of accelerating neutrons?

It is shamefully charge-free. But presumably, if we can tune its velocity, a lot of interesting things can be done, right? So, was there any proposal for obtaining high velocity neutrons?
3
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2answers
117 views

How neutron can have an antiparticle since it have zero charge?

Antiparticles are defined as fundamental particles having the same mass but opposite charge. Now, a neutron has a particular mass (say m) , but zero charge ( =0). Its antiparticle should have mass=m ...
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0answers
80 views

How do we know that electrons are affected by gravity?

There are some theories of gravity which explain it as emerging from other fundamental forces. To better understand the evidence for and against these theories, I would like to have a better ...
4
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3answers
126 views

Why does a “typical” hydrogen atom have no neutron?

There are quite a few sources (mostly high-school physics textbooks) that I've read which don't give the disclaimer that the hydrogen atom they are using in a diagram is an isotope (as in having ...
1
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1answer
35 views

Why don't degenerate gases expand from heat?

Degenerate gases are excellent conductors of heat. However, the fermions that compose the gas will not expand outwards due to heat, except in incredibly high temperatures. Why is this? Does it have ...
0
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1answer
40 views

What are the experimental results of neutron -neutron scattering?

I'm curious about does a neutron - neutron scattering (if such an experiment was carried out) is an in elastic process or is it accompanied by energy losses. Additional question: What is the energy ...
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2answers
46 views

How many neutrons would it take to boil a gallon of water? [closed]

How many neutrons would it take to boil a gallon of water?
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2answers
55 views

Arrangement of Nucleons due to Strong Force

I was reading up on the fundamental forces of nature and I was wondering about the arrangements of nucleons due to the strong force. Considering electromagnetic repulsion, having 2 protons "bonding" ...
1
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0answers
28 views

Can there be a two-neutron bound state? [duplicate]

Is is possible for two neutrons to be in a bound state, assuming that they only interact gravitationally?
0
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1answer
14 views

which unit cell to use for dynamic structure factor in neutron scattering?

I'm trying to calculate the dynamic structure factor for inelastic neutron scattering, but I get a function which doesn't obey certain symmetries of the crystal lattice and which changes depending on ...
0
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1answer
83 views

Collision with a stationary Hydrogen atom [closed]

Can some explain me what happens when an electron or neutron collides with stationary Hydrogen atom? What are conditions for elastic and inelastic condition? For example, how to tackle following ...
1
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1answer
66 views

Why positron emission is unlikely to occur for nuclei with an excess of neutrons?

Is it because a neutron decays into a proton and electron rather than a positron. Which type of nucleus emits positron and which emits electrons . Is it something to do with beta plus and beta minus ...
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1answer
48 views

How are neutrons made?

How are neutrons made? Perhaps no-one really knows, but I'll ask anyway. Are they still being made? or were they all made at some early instant of the universe?
1
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1answer
39 views

Atomic radii for elements as hard spheres

In neutron scattering, the atoms in a system are considered as hard spheres. Where could I find the appropriate (reliable) values of the atomic radii consistent with this physical picture? Thank you ...
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0answers
24 views

Why isn't every magnetic neutron scattering peak a nuclear scattering peak as well?

Neutron diffraction is a well-established technique for determining the magnetic unit cell of magnetic materials. The idea is that nuclear scattering gives you peaks that correspond to the crystal ...
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2answers
435 views

How does zinc affect fast neutrons?

How does metallic zinc interact with nuclear fission? Is it transparent for fast neutrons, or does it interact as a reflector (tamper), absorber, or moderator, or some other way yet? I'm asking it ...
2
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1answer
69 views

Which properties control the strength of strong interactions?

Does the strong nuclear force depend on mass, charge or spin? Accordingly, can we order neutron-neutron, proton-proton and neutron-proton pairs by the strength of the strong force between them?
1
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1answer
54 views

Neutron population growth in a reactor

In nuclear reactors physics, the effective constant $k_{eff}$ is defined as $$k_\text{eff} \equiv {\text{number of neutrons in one generation}\over \text{number of neutrons in the preceding ...
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2answers
146 views

Why don't neutrons cluster on their own?

"The answer lies in their one part in a thousand extra mass. Adding neutrons costs a little in mass, and in Einstein $E=mc^2$ implies that mass equates to energy. So it costs energy to add neutrons(...
2
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1answer
64 views

Is it possible to tidally lock a neutron star?

As I know, neutron stars are almost perfect sphere and no net moments, does it mean it is not possible to tidally lock it?
1
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1answer
33 views

What is the physical interpretation of imaginary terms in the neutron optical potential model?

I'm doing a computational project on neutron scattering and I've found that if you simulate (n,n) collisions on Uranium 238, the program predicts resonances not found in experimental data. The ...
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2answers
103 views

How is an electron “recycled” in a neutron?

A proton is made up, they say, by 2 up and 1 down quark, drowned in a sea of virual paricles: when an electron is captured this process thereby changes a nuclear proton to a neutron and ...
0
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1answer
32 views

Neutron scattering off molecules

From neutron scattering off molecules it is possible to get information about molecules' geometry. Given the size of a particular molecule, what are the criteria for choosing the wavelengh of the ...
3
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0answers
12 views

Why is this result wrong for finding speed of a neutron in relation to deBroglie wavelength [duplicate]

So given a deBroglie wavelength 1.8nm and the equations E=hf and E=1/2mv^2 you can get v = 2h/m*(1.8*10^-9) but this is 2 times the expected value. Wherever I look online people use the momentum p ...
6
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0answers
165 views

Intensity of inelastic neutron scattering: analitycal expressions

I am currently working with experimental results of magnon spectrum (in antiferromagnet with many atoms per unit cell), which was obtained by inelastic neutron scattering method, but some spectral ...
2
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2answers
80 views

Why did James Chadwick use berryllium to discover neutrons?

In Rutherford's alpha particle scattering experiment he used gold foil because it's malleable and can be drawn into very thin sheet. Why did James Chadwick use Berryllium while discovering neutrons ...
0
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2answers
121 views

A Neutron Star and an Atom are Similar [closed]

In an earlier question I asked if photons could exist without atoms. Is a neutron star's residual light released similar to an exited atom the difference is gravity hold in the electrons in the star ...
3
votes
1answer
48 views

Neutron activation time for Boron, Silver, and possibly other materials

How do i justify/explain that the time needed to activate Boron is 2 hours and the time needed to activate Silver in water is 45 minutes? Response to comment: In a neutron cross section experiment, ...
4
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3answers
118 views

Would a bag of neutrons have temperature?

Neutrons interact with each other only via exchange interaction, while "every-day particles" and their temperatures are governed by electrostatic forces. What are the implications of this difference ...
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0answers
33 views

Does an atom become positively charged as a result of Beta decay? [duplicate]

Since a neutron breaks down into an electron and a proton, and the electron is emitted as beta particles, the atom has an extra proton (protons>electrons). So, the atom becomes positively charged. But ...
2
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1answer
105 views

Is Neutronium possible?

Now I am not talking about neutron stars here. I am talking about a supposed substance with only neutrons in the nucleus. All atoms of this category would have a negative charge and negative charge ...
3
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1answer
99 views

Is neutron-neutron fusion viable?

Do I get unusual baryon maybe like pentaquark or just a pair of conjoined twin that is very unstable?
2
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3answers
107 views

Head-on collision between two neutrons

If two neutrons were set to collide head-on, being electrically neutral: Will they feel each other's presence due to electrostatic interaction between quarks of approaching neutrons? When they ...
1
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1answer
62 views

How are neutron refractive indices calculated?

I have been informed of the fact that neutrons refract similarly to light in accordance to Snell's Law. How would one calculate the refraction index for a neutron?
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3answers
97 views

Can a neutron decay to the gravitons?

Is it possible that a bunch of neutrons totally decay to the graviton? In other words, does the baryon number conserve in the quantum gravity interactions?
4
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1answer
163 views

Why do neutron stars have solid crusts?

A long time ago I read that neutron stars have a solid crusts that are several orders of magnitude harder/stronger than alloys here on the Earth. So how is this possible ? A neutron star has a ...
0
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2answers
60 views

Can both types of W boson be responsible for a neutron-neutrino interaction?

My textbooks lists the exchange particle for a neutron-neutrino interaction as being the W- boson. Is this the only option, or can it also be a W+ boson? Nothing jumps out at me that would suggest it ...
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0answers
37 views

Question on decay constant

I have a model of the radioactivity of a target which is undergoing Neutron Spallation. The Protons are incident upon the target for approximately 200 hours. Within the model, over the course of ...
0
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2answers
35 views

Can multiple adjacent reactors use neutron reflector walls in common to save mass?

Reactor designs like fission-fragment and some others use large masses of neutron reflectors to attain criticality. (For that matter, the very first pile did too, and in a staggered form rather ...
0
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4answers
83 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?
1
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2answers
35 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 ...
4
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0answers
53 views

Which is the mechanism through which dying stars shed their outer atmosphere and leave behind their core? [closed]

I was looking into neutron star creation and I read that when a star dies, it expells its outer atmosphere and leaves behind a really small really dense nucleus (a white dwarf if the first star was a ...
1
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2answers
42 views

Can we create sheet of neutron

I want to know are there any theory or technology to create a neutron matter like neutron star on earth. Even a tiny thin sheet like graphene And how heavy it is if we create 1x1 sqmm of neutron ...