Neutron Definition and 771 Threads

Does anyone know if an average Neutron star with a diameter of 10 miles, was headed towards Earth.. would our Nuclear weapons be able to physically destroy it? Assuming our technology can provide a direct hit, and do it in time. If so, then how many Megatons would the Nuke need to be, and how...

Homework Statement What is the rest mass energy of one mole of neutrons? Hint one mole is 6.02 x 1023 particles (avocado's number), and the neutron has mass m=1.675 x 10 -27 kg. Homework Equations The Attempt at a Solution I wasn't sure of the relationship between moles and...

What is the minimal mass of a neutron star, if the semi empirical mass formula is used?

I have a decent understanding of neutron-induced reactions in heavy nuclei (fission, capture), but less so when light nuclei are involved. I do know of Li6 + n --> He4 + T and the Li7 equivalent. Those reactions are more like nucleus splitting (fission). My question is: do neutron capture...

Hi there, I'm a lay person and would appreciate if anyone could point me in the direction of a good theoretical explanation of the neutron. All I can remember from high school physics is an explanation that went something like:- "Uh, well it doesn't actually do anything, it's just there do make...

Wikipedia said U-238 is better with capturing fast neutrons than slow neutrons. shouldn't it be the other way round? I thought U-238 is not fissile but is fissionble by neutrons with high enough K.E, and doens't fast neutrons have higher K.E.??

well, that's the question. They both have the same queark structure. (udd). is it only their different bound states the differentiates them?? thus giving both different masses?

As I understand it, it can be calculated that 1 minute after the big bang, when protons and neutrons freeze out and are no longer being created, that for every neutron that exists there are 7 protons. Does anyone know what equation is used to calculate this and if it is not a equation that is...

I need help with this problem where we are suppose to determine the fraction of kinetic energy lost by a neutron m=1.01u when it collides head-on and elastically with a target particle at rest which is. examples used.. Hydrogen = 1.01u heavy hydrogen = 2.01u How would you do this? Do...

Here's one for everyone to ponder.. Firstly, this question has always bugged me since I was born. It's not impossible to imagine an Alien civilization 1.5 billion years more advanced than us, using the method of 'Hurling Neutron Stars at 99% the speed of light, to destroy planets and their...

I was told that if there is a wavefunction containing a proton and a neutron that it must be anti-symmetric under exchange of a proton and a neutron. I am having trouble understanding this. The short handwavy explanation is that they are indistinguishable via the color force. What bothers...

Well I was talking to my physics teacher because were currently studying nuclear physics. And he likes tellign stories to make his examples more straight foreward. And I asked the question what types of radiations are in nucleaar bombs. Gama, Beta or alpha. He answered me with those three types...

how plausible is it to image a single molecule using low energy neutrons? I was thinking it might be possible to build something similar to an interference microscope in order to accomplish this however I'm not entirely sure. I was thinking of doing a little research project on the mechanics...

In Modern Quantum Mechanics, Sakurai say that at quantum level the gravity is no more geometrical because the schrodinger equation depend on the fraction \frac{m}{\hbar}. Can someone explain better this claim or link me some detailed paper on this argument?

I want to know if a photon can interact with a neutron? I understand that a photon will mediate the electromagnetic force between electrically charged particles (such as electron and proton). This is even manifested in the photoelectric effect. So, I presume when we "see" matter through...

Since a neutron has no charge and an electron is not involved in the strong nuclear force, does this mean that an electron has no interaction between a neutron? As in a very dense neutron star, would we expect that electrons could easily pass right though without being absorbed/deflected in any way?

Here is a beta decay related question: Masses are from Particle Data Group (http://pdg.lbl.gov/2008/listings/contents_listings.html) Neutron has udd quarks. Mass is approximately 2.5, 5, 5 MeV. Total 12.5 MeV Products are: 1. Proton. uud quarks. Mass approx 2.5, 2.5, 5 MeV 2. Electron...

Homework Statement which of the following has closed neutron shells? (the number in front should be a superscript) 36S, 50V, 50Ca, and there are more but i just want to understand why. Homework Equations The Attempt at a Solution i know the answers, i just don't know how to get...

Quark motion inside a neutron Using electron-neutron scattering I'm trying to find out how the three quarks (udd) behave inside the neutron. S.Kopeky (Phys. Rev. 1995) found that for small Q2 the equation for the neutrons rms-radius goes towards: -6 \hbar \frac{dG_E ^n (Q^2)}{dQ^2}...

Using electron-neutron scattering I'm trying to find out how the three quarks (udd) behave inside the neutron. S.Kopeky (Phys. Rev. 1995) found that for small Q2 the equation for the neutrons rms-radius goes towards: -6 \hbar \frac{dG_E ^n (Q^2)}{dQ^2} \right|_{Q^2=0} = -0.113 \pm 0.005...

Hello! I have a very interesting question, whose answer I have not yet been able to find out. Now, according to The Standard Model there are three generations of matter, therefore three generations of quarks also. Generations of Quarks: 1st: up (u) & down (d) 2nd: charming (c) &...

I had a homework question I am really stuck on- How do you calculate neuron flux

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to move off at an angle θ'2 = 45° from the neutron's initial direction. The neutron's initial speed is 7.0 × 105 m/s. a) Determine the angle of...

Homework Statement Supposed that the mass of certain spherical neutron star is twice the mass of the sun (1.991*10^30) and its radius is 13.5 km. Determine the greatest possible angular speed it can have so that the matter at the surface of the star on its equator is just held in orbit by...

1. A neutron has a kinetic energy of 10MeV. What size object is necessary to observe neutron diffraction effects? Is there anything in nature of this size that could serve as a target to demonstrate the wave number of 10MeV neutrons? K= 10MeV or 1.602 x 10^-12J Mass of neutron = 1.675...

This question concerns a problem in Arfken and Weber (from the infinite series chapter, after the power series section). I went to the homework section, and the titles beneath each section specifically imply that a question from a graduate book is inappropriate for that section. I thus post it...

Calculate the velocity and kinetic energy of a neutron (mass 1.675x10-27kg) that has a wavelength of 0.2nm. How does this compare to the average kinetic energy of a gas molecule at room temperature (0.038eV at 200C)? 1. E=mc^2 2. KE = 1/2 mv^2 I used 1. to calculate the energy which was...

Does anyone know anywhere where I can find reliable up-to-date cross section infromation? In particular I'm looking for the absorption cross section of Gadolinium-157 for thermal neutrons. Everywhere I look seems to give a different value ranging fro 70000barns up to 450000barns.

I know there is no way to deflect a neutron by electromagnetic force since it is a uncharged particle.Can anyone come up with any other ways?Thanks very much.

how to turn a proton into neutron by e+p-->n? Just as the topic said,is it possible to turn a proton into a neutron by forcing a electron into the proton?If it's possible,what condition is it required?

Homework Statement Calculate the binding energy of a neutron in 13-C. Homework Equations mass defect= (Z*mp) + (N*mn) - (mc13) B = mass defect * conversion factor B/(Z+N) = Binding Energy per Neutron I wasn't given any values for the numbers, so I wiki'd them. The Attempt at a...

This question is probably very basic for those who understand nuclear fusion but it has been annoying me for a while now and I would like an answer. I have tried searching these forums but I can't find what I'm looking for. The sun is constantly fusing hydrogen atoms to form helium atoms...

A neutron star cannot spin with less than a certain critical period, or else it will start to lose mass from its equator due to the “centrifugal” force. Estimate this period.

I seek some links for pointers to be able to answer the question .. "Given that neutrons can approach each other easier than protons, and that the Strong Force will hold neutrons to neutrons when they get within the (short!) range where the Strong Force can be effective, why do we not have pure...

If anyone can help me with this question I'd be greatly appreciative... Here's what I think I understand: Nuclear fission is the breaking of an atomic core of an atom. Like with U-235. It absorbs a slow moving neutron which yields the unstable U-236. Because of the instability the atomic...

can someone Explain the NS-NS or NS-BH or BH-BH mergers proposed to explain short GRB’s. Thanks

Problem Given that \frac{2ma^2 |V|}{\hbar^2} = \left(\frac{7\pi}{4}\right)^2 for an electron in a potential well of depth |V| and width 2a = 10^{-7} \text{cm}, if a 100\text{-keV} neutron is scattered by such a system, calculate the possible decrements in energy that the neutron may...

I want to know more about the cross sections in reaction neutron + targets which neutron has energy in the resonance of target. Help me!

An isolated neutron, changes to a proton within 15 minutes by one of the down quarks becoming an up quark. Why does the change need to include the intermediate step of the heavy W boson? Where did all the W boson mass come from and where did it go? jal

You can calculate that the proton and neutron in a deuteron spend quite some time so far away from each other, that they are outside each others force range. Why doesn't the deuteron break up? Is it because of the binding energy?

well, that's the heading of a project i am doing...i need some help on neutron detectors... how they are dectected and what is the probable graph of count rate vs, pulse height that i might get for a nuclar fission reaction of U-235... can anyone help?

Hey! What would happen if you were orbiting a neutron star and shot a powerful laserbeam at the surface, at some angle? Would it reflect? Would it be absorbed? Thinking (if you picture the star as a perfect neutron star) that the surface is absolutley smooth, it would reflect light...

We all know that the magnetic moment is (gq/2m)J, so then why does a neutron precess in a magnetic field if q=0? This should cause the Hamiltonian to be 0.

It seems strange that a neutron wouldn't have a function within an atom other than obtain mass, a neutral charge, and stick to protons. Do neutrons have more gravity than protons?

If a proton and neutron have a mass of roughly 1.67e-27 kg . And a proton has a diameter of 1.65e-15 .. Is the diameter of a neutron the same?

Neutron bombs (not that we hear much of them now) are said to produce intense neutron radiation but little blast. I long wondered how this could be done. It then occurred to me that fast neutrons from the DT reaction in a thermonuclear bomb could drive the energy-absorbing reaction Be-9 + n...

Homework Statement A neutron star has a mass of 2.0 x 1030 and a radius of 5.0 x 103. Suppose an object falls from rest near the surface of the star. How fast would it be moving after it had fallen a distance of 0.010 m? (Assume that the gravitational force is constant over the distance of the...

Can somebody please explain effective neutron multiplication factor, with example? So when k=1, k>1, k<1 , please give me some example. k=\frac{N_2}{N_1}=\frac{N_3}{N_2}=...=\frac{N_i}{N_i_-_1}

hi there, friends of physics, could anybody help me? All we know that electrons have 4 quantum numbers that describe them and -as the Pauli exclusion principle said- it can´t exist two electrons with the same quantum numbers. But I have a question, does protons and neutrons have quantum numbers...

Is neutron diffusion, traveling neutrons from the nucleus, to direction outside of the nucleus? In my textbook says that there is neutron diffusion, where there is not nuclear reaction. In that case are neutron bouncing off the nucleus?