Neutron Definition and 746 Threads

Hello, Can somebody please tell me in details about the rotation speed of a neutron star? Does it rotate very fast and then slows down? Thanks.

Hello, I want to understand: just as the Crab Nebula is the result of SN 1054 and has a neutron star spinning at the center: (a) Does all supernova produces a nebula? (b) Does all supernova remnant has a neutron star at the center? (c) What is the outcome of Kepler supernova i.e. SN...

Pulsars -- Rotating neutron star produces EM radiation? Hello, If a neutron star is composed of neutrons, which do not carry any electric charge then how it's rotation produces pulsars which are electromagnetic radiation? Thanks.

Greetings to all, I know activity for a Am-Be neutron source. I want to compute strenght source in neutrons/s. Yours advices are welcome. Thank you!

Hi could you please explain me what happens with the atomic structure and overall material structure of neutron absorber rods used in fission reactors? As I imagine when they are used they absorb the neutrons that keep the chain reaction going so to stop the chain reaction hence shut the...

If a proton, a neutron and an electron have the same total energy than rank the the particles in terms of most momentum to least momentum This is the first problem I attempted after learning about special relativity. I used the equation E^2 = \rho^2 c^2 + (m c^2 )^2 Since the energy is...

On decays I have only a preliminary understanding. I was looking up the half life of a neutron for another reason. The value I found for neutron decay for a free neutron was 10.3 seconds. Hope that's reasonably accurate. Anyways knowing that neutrons are stable in a nucleus held together...

can anyone give an example in which a nucleus absorbs a neutron and becomes a stable nucleus? or the combination must break into parts?

Homework Statement About neutron stars we can say that: a) They are newborn stars b) They are generated when a Solar-type star dies c) They are generated when a very massive star dies d) They are in the main sequence Homework Equations None. The Attempt at a Solution I'm...

Part 1----------------------------------------- Ok, the site I have just read through is http://burro.astr.cwru.edu/stu/stars_lifedeath.html one. I have a few questions about it. Firstly, about the fusion of helium into hydrogen... http://burro.astr.cwru.edu/stu/media/fusion.jpg It...

My research is about Design and modeling of beam tube of nuclear reactor for BNCT(Boron Neutron Capture Therapy) application and I need some journals and related books about it.

The following problem appeared on the A2 Edexcel Physics unit 4 exam paper January 2012 question 18. The solution, as given by the exam board, is attached. Question: 18. James Chadwick is credited with discovering the neutron in 1932. Beryllium was bombarded with alpha particles, knocking...

I have been looking for experiments demonstrating neutron interferomerty with protons or electrons instead, and found non. Should there be any difference? I refer to experiments in which, for example, the Mach-Zehnder interferometer is cut from a single crystal.

The mass of proton is 938mev/c2 where as mass of quarks in proton is 11 Mev/c2. Much of the reminder is gluon. But gluon does not have any mass. So how can it be gluon? Also in neutron decay, one d Quark transform itself into u quark by absorbing / emitting W boson. in this case W boson is...

Hi All, Trying to write a simple Monte Carlo code for mono energetic neutrons in a steady state slab geometry in one-dimension. Their is an incident source on the left hand side of the slab and its of length L. I understand how to work out the path length and scattering angles based on...

Hello people, I think the problem what I have is well known in experimental physics. Hope, somebody can helps me, thanks in advance. Here is: There is a source of neutrons with a flux of λ neutrons per minute, which you do not know and want to estimate. You open the detector for one minute...

Homework Statement What is the de Broglie wavelength of a neutron that has fallen 0.60 in a vacuum chamber, starting from rest? Homework Equations Not entirely sure λ=h/mv The Attempt at a Solution I can't figure out what the velocity is, I think it would have to do with the change...

neutron capture --> gamma's Someone could explain me how neutron capture in Gadolinium happens? If a neutron is captured, an energy of about 8 Mev is released in form of gamma-ray cascade (Ʃγ). But... how many gammas are released? I believe the answer will be in form of probability...

in general how to calculate binding energy of neutron star? in simple details, what tricks may be included in such a problem..

As I know, the method to solve neutron problem is divided into two steps now, neutron transport calculation for fuel assemblies and neutron diffusion calculation for whole reactor core, both using specified code such as CASMO and SIMULATE from STUSVIK. I want to know whether the commercial...

Hi, I'm considering the following process n+p→d+\gamma where d is the deuteron and \gamma a photon. I want to find out the energy of the photon. I know it will be much less than the rest mass of the deuteron (1875.666 MeV/c2). Can I simply use conservation of energy here? i.e E\gamma...

Hope mods will allow this. Seeking comments on neutron detection techniques described in the linked paper. Authors are affiliated with China Institute of Atomic Energy, Beijing. This is a LENR paper with no theoretical content. Full text is free to download...

I wrote a paper in the physics department's student newspaper at my school, which described why, in my opinion, I considered a neutron star's surface as the smoothest surface in the universe, I considered the space between the particles at the surface (thousands of times smaller than at TPN...

Does the strong force have any major role in neutrons stars other than obviously holding individual nuclei together? Would low energy neutrons tend to "clump" together in the core?

Deaar all good morning I am very interested to the flux in a slab of extrapolated thickness a, containing distributed sources of neutron. A I have an example in which the source is given as s(x)=S(x+a/2) where S is a constant and x distance from the center of the slab. You mentioned in one...

If Neutron stars are what they are... I mean made of literally only neutrons ...how do they generate such immense magnetic field (of the order 10^8 or something) .. I think the name is somewhat misleading and it ought to have a near half ratio of protons ...But still being so compact how...

I wish to verify a couple of assertions. From the NNDC and other references, it appears that the neutron capture cross section of 3H (Tritium) is zero to a first approximation. This holds true for all neutron energies, including cold neutrons. These statements are equivalent to asserting that 4H...

Hi Everyone, Does anyone know of a tool that can extract thermal neutron cross-section data from endf for all availible isotopes? I'm trying to help my professor compile some data to modernize one of his courses. I'm trying to find a list of capture and scattering cross-sections for a wide...

I was wondering today what is the colour of pure neutrons confined together, I'd guess it's either completely black or white, because it doesn't have the electric orbitals needed to generate different wavelengths. I'm generally guessing it just reflects light and is therefore what... maybe a...

Hello! J(Ω) = ∫n(Ω)vΩdΩ This is a neutron current question. It wants me to figure out the net neutron flux (and direction) through a unit area of the xy plane. It gives an equation for n(Ω) = (1/4π)(1-cosθ), but I am trying to figure out what Ω is inside the intergrand because that is...

In the Wikipedia article "Quantum Gravity", it claims that there is some experimental motivation for finding a quantum theory of gravity. In one of the experiments it cites, neutrons are found to jump between discrete quantum states in the Earth's gravitational potential, similar to the discrete...

2 closely orbiting massive objects are predicted to deserve the fabric of spacetime so much that they will release a ripple of gravitational waves. When geavitational waves are released, they slowly loose velocity energy and spiral into one another. 2 pulsars were discovered orbiting each other...

The situation is this: In a neutron star the Coriolis force induces Rossby waves, just like on Earth. These are waves with very long wavelength -- like halfway around the Earth -- and very large volume but very little amplitude, like fifty meters. On Earth they have a big effect on climate...

Ive been researching for a while now and i still can't understand why neutrons rich isotopes are unstable. As neutrons act like the glue and hold protons together as they increase the Strong Nuclear force that act upon protons and neutrons, i thought the more neutrons the stronger they would...

Homework Statement Suppose that there is a beam of neutrons with a range of wavelengths. One intends to produce neutrons of single wavelength by the use of neutron mechanical velocity selector. The question is, if the slot in the disk B (second disk) of the selector lags the slot in the disk...

Homework Statement Under some circumstances, a star can collapse into an extremely dense object made mostly of neutrons and called a neutron star. The density of a neutron star is roughly 10^{14} times as great as that of ordinary solid matter. Suppose we represent the star as a uniform, solid...

With beta decay a down quark turns into a up quark + W- results in e- and (anti-neutrino) and up quark turns into a down quark + W+ produces e+ + (neutrino), does the W- and W+ get emitted and then turn into e- + (anti-neutrino) or e+ + (neutrino) or do they stay in the nucleus? How does the Z...

what if...Neutron stars I know likely its been answered but if two neutron stars collid, it wouldn't seem that there combined massess would forum a black hole...if I recall that any matter striking the surface of a neutron star impacts with such violence that there is a massive explosion. So I...

why is hydrogen the only element in the periodic table that lacks a neutron?

If proton decay does not occur, will neutron stars just last for eternity unless something collides with them?

i need a help in solving ,using 1 group approxmation , estimate the critical size of cube consisting of 75% zirconium-91 and 25% plutonium--239 by volume , when the cube is surrounded by a vacumm. zr-91 microscopic cross section (capture)=0.00335 microscopic cross section (scattering )=5.89...

hello, I am new to MCNP, could somebody tell me how to use imp:n, what is imp:n=0 means, if neutron importance is 0 in one cell, why the F4 tally is 0 in this cell? how about imp:n=1 or some large number? Thanks for all.

Ok, I know neutron stars are mainly composed of neutrons. But also, they have some protons and normal nuclei at their surfaces. Is this crust of protons needed to keep the neutrons below stable? As in, if it disappeared, would the neutrons below start decaying back to protons to form its...

Why do different nuclei need different neutron speed to achieve fission?? My understanding is that U-235 requires a thermal neutron in order to be likely to cause a fission reaction, however Pu-239 requires the additional energy of a fast neutron in order to cause the nucleus to undergo fission...

Hello, I was reading about big bang nucleosynthesis recently (If it helps, I'm using Mukhanov) and it was calculating the abundance of neutrons. It seems to say that X_n→X_n^{eq} (It says that X_n^{eq} is the equilibrium abundance of neutrons) as t→0. So...does that mean that the neutrons...

There is a recent article about neutrons and how they escape to parallel universe. It is only a theory. You can probably find it by googling the title. How and when will they test for this? Is this likely to be true? Are there multiple universes or only an additonal universe plus are own?

After reading "The Five Ages of the Universe" by Greg Laughlin and Fred Adams, I wondered, if all matter composed of ordinary atoms (protons decay) decay, and black holes decay due to Hawking Radiation, do neutron stars decay in any way? They are composed entirely of neutrons that are kept...

I have had a question that I cannot get an answer for. I recently had an exam for energy in the nucleus which included a question about why lead nuclei would be inadequate for use as a moderator in a reactor. When I got the answer for the question, it stated that the lead nuclei reflect neutrons...

Hi, I'm a new member in the forum. I own two similar GM military grade meters with calibration certificates, calibrated for gamma-rays metering and each one has two tubes filled with helium, argon (or neon), halogen (or quenching) gases. When I am exposed to some radiation source, my GM meter...

Homework Statement What is the maximum kinetic energy (in keV to 3 significant figures) of an electron emitted in the beta decay of a free neutron? Write down the decay equation using accepted notation. Mass of a Neutron: 1.008665 u Mass of a Proton: 1.007276 u Mass of an Electron...