Neutron Definition and 746 Threads

I see that in some books, Proton and Neutron charge differ a bit. Why is it? :confused: I thought them to be same. But... And I am new to this forum... Let's hope we will have a great time together studying science...

Is it possible for a beam of slow neutrons, to be deflected by a strong magnetic field? I have found something for a beta asymmetry in Wu experiments, but haven't understood much. Is it a particle physics subject?

Does anyone know what the necessary conditions are for a nucleus to undergo fission with a thermal neutron? I have found something for the chain reactions, but not very helpful. I want to find out the conditions for ONE nucleus to undergo fission with a thermal neutron.

Homework Statement 1)Neutron emission is not a possible mode of decay for K(40,19).Why? Homework Equations The Attempt at a Solution I think it is because the neutron to proton ratio for potassium(40,19) is almost unity(more precisely N/P=1.1). So, neutron emission is not a mode...

Homework Statement 1) In a sequential process, U(235,92) plus a neutron forms the compound nucleus [U(236,92)]* which then fissions; the fissions then produces decays. If the initial fission fragments are Ba(143,56) and Kr(90,36), illustrate a process leading to the final stable nuclei...

Consider a reactor being held sub-critical, Keff < 1, by control rods. The reactor has heavy water reflector and has been operatored for some time prior to the current state (we got Photo Neutrons). Keff is then bought to 1. It seems to me, for Keff = 1 the neutron population should be...

can a neutron decay into a proton? i certainly didnt think so, but i am reading hawking's new little book "breifer history of time", and he states that in there while talking about the early universe. thanks.

Hi guys, I'm not to great at physics and all but I want to learn more. I hope you guys can help me in that aspect.First of all, how do neutron stars form? I was told their electrons shrink into their nucleuses and therefore the whole star shrinks, but what causes the atoms to behave like that?

A (free) neutron has a lifetime of some 10 minutes or so, how come it is stable in a nucleus?

I have a question about current experimental findings on the status of the neutron N while contained within nuclear radius of a stable atom, say Helium-4. It is well known that the N will undergo beta(-) decay when it is free from a nucleus (takes ~ 14 minutes). But... My question...

hiii guys, what's the binding energy of a neutron and how do you arrive at the answer? durrrrrrhhhhhhhhhh :confused:

I read a sentence in my book saying, The fast neutrons released through the first nuclear fission are passed into the moderator, thus producing (becoming) thermal neutrons. What is a Thermal neutron? What is the difference between Thermal and a Fast Neutron?

Hello, I can't find :confused: where do we get the starting neutron(s) for the chain reaction in the reactor. I'm aware that then the splitted atom emits enough(in fact even too much?) neutrons to selfsustain the reaction, which are then slowed down to be able to split uranium and so on...

I am plotting the in-hour equation. For the delayed neutron fraction, I was thinking of using a weighted dnf for the particular U fuel enrichment of interest, ie combination of U235 & U238 dnfs, as I cannot look one up for this particular enrichment. Any comment on the “validity” or otherwise...

Can anyone hepl me with this?I need some web resource,to start learning from scratch.

Hello, Can someone explain to me exactly why a bound state of two identical nucleons is not possible? I have a feeling its something to do with antisymmetric wavefunction, but haven't found a satisfactory explanation in any book. Cheers.

Homework Statement Suppose the sun collapses into a neutron star. What will its radius be? The questions also gives some backround explaining that stars fuse hydrogen into helium until they collapse into a neutron star. The protons and electrons fuse into neutrons with the density of nuclear...

The question is: Suppose the sun collapses into a neutron star. What will its radius be? The question gave a brief backround explaining that stars are powered by nuclear reactions that fuse hydrogen and helium. When the hydrogen is used up the star collapses into a neutron star. The force of...

A neutron star has a mass five times that of Earth and a 10 KM radius. Find the distance from this star's surface a satellite must be at to stay in a circular orbit if the satellite is moving at 50000 km/min. First, I changed the 10 KM to meters and found the mass of this neutron star...

Neutron stars represent the final stage of life for some massive stars. Typically, they have radii of 10 km. Determine the magnitude of the centripetal acceleration for a piece of neutron star matter on the star surface at the equator (so the matter moves in a circle of radius 10km). Assume...

I was wondering if some of you could describe a couple of the applications of a neutron generator and or suggest some further reading on the types of such?

Does anyone know of a good reference regarding solving the Tolman-Oppenheimer-Volkov equations for neutron stars? Most things I find are either too elementary and others skip multiple steps. I think the EoS to use should be that of a Fermi gas model, but I am not sure.

I was intrigued by this paper, and apparent implications for Smolin's cosmic natural selection [CNS] conjecture. http://arxiv.org/abs/astro-ph/0609644 Observational constraints on quarks in neutron stars Authors: Pan Nana, Zheng Xiaoping Comments: 16 pages,6 figures We estimate the...

Does anyone know if there are descriptions of the neutron and proton configurations in atoms and why certain configurations are more stable than others. For example the average atomic mass of oxygen and flourine are the whole numbers 16 and 19 while most other elements have more variation...

hi, in neutron scattering, if the lowest kinetic energy of a neutron is increased by a factor of 2, how do you work out the number of peaks produced? I have worked out the lowest kinetic energy for a beta-brass CuZn to be 2.37meV using [tex]E=\frac{\hbar^{2}k^{2}}{2m}[\tex] where...

We were having a little chat in my physics lesson about neutron stars for our A level course, and nobody really understood why neutron stars have a magnetic field if they are consist of neutrons, which are obviously neutral charge. We thought that you needed charged particles to create a...

The situation involves a neutron in a constant gravitational field (g=9.8). I need to find the energies of photons that transition to the excited state. I solved the Schrodinger equation by doing a variable transformation using Airy functions. To fully solve, however, I need to find the roots...

There is a good review article on inelastic neutron scattering experiments and results on hole-doped cuprate superconductors. One of the authors (Tranquada) was the first person to report experimentally on the possible existence of the stripe phase in such a compound using the same technique...

taking a set of questions and came across this one: "Capture of a neutron by nickel-60 produces a proton and what new element or isotope ? " I thought it was copper-61 since it goes through beta decay as indicated by the proton but supposedly it is not... please help

This is one of those old-high school questions that never got answered (And the search mechanism here doesn't narrow on quotemarks)-- A neutron decays to a proton, electron, antineutrino ... But the highspeed escaping electron is a charge moving relative to (away from) the proton opposite...

Is there anything in the observable universe that weighs more? 1 teaspoon = billion tons

A neutron can decay into a proton, a positron, and a neutrino. A proton is made up of two up quarks and a down quark. A neutron is made up of one up quark and two down quarks. An up quark has a charge of +2/3, and a down quark has a charge of -1/3. Given the statements above, can someone...

Basically the steady-state diffusion equation can be written in a form \nabla^2\phi\,+\,k^2\phi\,=\,S When S = 0, this is just the Helmholtz equation - http://mathworld.wolfram.com/HelmholtzDifferentialEquation.html See also -...

In the text I use for class, the examples and derivations for functions showing the neutron flux at some point, are all about sources within infinite mediums. Now I have a probelm where I must show that neutron flux, for a point source within a finite sphere, is found by the following equation...

I am to calculate everything in a non-relativistic state: a 15MeV photon is completely absorbed in colliding with a neutron initially at rest. Determine the speed of the neutron: conservation of momentum: E=\frac{hc}{\lambda} 15MeV=\frac{1240MeV nm}{\lambda} \lambda=8.2667x10^{-5}nm...

I assume that the neutron is a particle with finite size and is <really> a single particle (that is that it does not have any further structure or components-like nucleus) and lastly it is electric nutral. I hope that these assumptions are close to the experimental observations. I am making life...

neutrons are fermions, with half spin, as such the must not occupy the same quantum state (meaning the wave functions can't overlap - atleast not with a big probability density portion of each other). so, if neutron star is in the most dense state it can get, meaning its degenerate and every...

Hello, I'm new to this forum. I was hoping someone might be able to help me understand what the constituents of a neutron are. Last month I read a book that stated that the neutron was composed of 2 'd quarks' and 1 'u quark'... while the proton is composed of 2 'u quarks' and 1 'd quark'...

I was reading about neutron stars and wonder if anyone can help me with something that puzzled me , namely what happens to the electrons in such a mass of atomic neuclii? I can only see there might be 2 possibilities .Either 1) that the electrons are expelled from the atoms during the collapse...

I understand the difference between the two main Neutron decays but, is there an observable difference when an electron collides with a neutron compared to a positron colliding with a neutron? In particular, I need to know if there is a difference in the behaviour of the neutron.

what is deffrence between nutron energy spectrum and nutron flux

Is a neutron star held together mainly by the strong force? Are they dense enough so that this is the case, or is gravity the only thing to consider? What about black holes?

Neutron fluence at the reactor pressure vessel wall a comparison of French and German procedures and strategies in PWRs U. Jendrich (GRS), N. Tricot (IRSN) Abstract: While the neutrons within the core may take part in the chain reaction, those neutrons emitted from the core are basically...

A He4 nucleus, with a mass of 4 amu moving with speed v breaks up into a neutron 1amu and a He3 nucleus 3amu . If the neutron moves in a direction perpendicular to the direction of motion of the original He4 nucleus with speed 3v, what is the speed of the He3 nucleus? if the neutron moves...

Nasa team has solved a great mystery:http://www.nasa.gov/mission_pages/swift/bursts/short_burst_oct5.html

press release from NRAO http://www.nrao.edu/pr/2005/fastpulsar/ The fastest-moving neutron star ever seen, clocked at 1100 kilometers per second, a speed that will take it out of the Milky Way galaxy, was given its initial "kick-off" by the supernova that formed it. journal article...

What are they? :confused:

Why does a neutron not decay in some nuclei? Why does it decay in other nuclei? Is there some mechanism suppressing the d quark -> u quark + W- boson channel? I'm looking for a fundamental QFT / Standard Model explanation. Thanks!

http://arxiv.org/abs/astro-ph/0506364 Title: Neutron Diffusion and Nucleosynthesis in an Inhomogeneous Big Bang Model Authors: Juan F. Lara Comments: accepted for publication in Physical Review D This article presents an original code for Big Bang Nucleosynthesis in a baryon...

I have a question about the time scale for a certain type occurance causing a neturon star to explode, and a related question about the conditions of this occurrance. If you have a binary star system with one of the stars being a neutron star, I read that if the other star sucks off enough...