Neutron Definition and 746 Threads

If proton decay does not occur, are neutron stars immortal? I was hearing that that was the case.

Homework Statement Calculate the energy of a neutron wavelength 0.1nm Homework Equations The Attempt at a Solution let L = lambda So i just use E = hv/L L = hv/E But how do i write v in terms of E? isn't E the total energy rather than just kinetic...

Does anyone know where I can find good tables for low energy nuclear processes? For example collisions to products like: - proton into a material yields neutrons - neutron into a material is captured to give different element - electron into a proton yields a neutron etc. Here's an example type...

I don't know much about quarks but if a proton is uud and a neutron is udd, is the (mass of a neutron)-(mass of proton)=mass of a down quark?

Can we calculate the difference in mass between a Proton and Neutron? If so, how? [ Moderator: why did you move this from QM to general physics? ]

Hi, I'm having some trouble interpreting an equation. In Lamarsh's Introduction to Nuclear Engineering. The formulae for neutron attenuation is: I(x) = I_{0} exp(-\Sigma_{t} x I am given the formulae \frac{-dI}{I(x)} = \Sigma_{t} dx This formulae has been described as "the probability of a...

http://www.physorg.com/news/2010-11-laser-neutron-yield-energy.html DT produces 17 MeV per fusion, so that's an output of about 800 joules; a factor of about 150X short of break even for energy applied to the target, and perhaps ~1000X short of the gain required for a practical fusion power...

How much energy does a neutron need to be able to split an atom and start nuclear fission?

A letter in the current issue of Nature: ==quote== A two-solar-mass neutron star measured using Shapiro delay P. B. Demorest1, T. Pennucci2, S. M. Ransom1, M. S. E. Roberts3 & J. W. T. Hessels4,5 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, Virginia 22093, USA...

When a neutron star flucuates into a black hole does the gravity increase tenfold? Or does the neutron star gravity (while turning into a black hole) increase as expected with the addition of more mass?

Homework Statement Suppose you want to observe neutron diffraction in a crystal with 0.27nm spacing between lattice planes. Part A asks for the momentum of neutrons with a wavelength equal to the spacing. I used p = h/lambda to get the correct answer 2.5×10−24kgms-1 Question1: Find the...

Dears I know that the neutron diffusion coefficient D= (The transport mean free path/3), but in some documents i read that:( D=The transport mean free path*v/3) where v=The neutron number. How is that?

Is there any direct evidence that black holes are smaller in size than (less massive) neutron stars?

Hello, I am looking at scattering cross sections for neutrons. From basic scattering theory and the partial wave expansion I have understood that the reaction and scattering cross sections are dependant of each other. There can be scattering without reactions but only 1:1 the other way around...

Firstly, I would like to say hello to everyone as this is my first post. I am an artist working a personal project that will be a visual investigation into the effects of a collision between a Neutron Star and Earth. The star would have a fully collapsed core at 1.5 solar masses (maybe...

Hi all I have been searching the internet but not with much luck. What can be expected to happen when a tritium is bombarded with a neutron of suitable energy? Will a neutron be knocked off or not? Regards bmeagle

Homework Statement The energy that binds an orbiting electron to the hydrogen nucleus is 13.4 eV. Calculate the ratio of the binding energy per nucleon to the binding per electron in deuterium. Which particle is held more tightly, the electron or the neutron? Homework Equations using...

If black holes are not real, just wondering? By the way they may or may not exist. But since some people don't believe they exist and some do, then if you DO NOT , how do you explain what happens to neutron stars that are 20 -25 the size of the sun? typo in the title, it should read: " what...

Hi guys. I have a small question and i would appreciate your help. I want to find how many neutrons per second (in 4π) are produced from a neutron generator. The generator works with T(d,n) reaction.. We have 0.5 mA d at 100keV energy that hits a target of titanium-tritium that has 2*10^20...

I always here about neutron stars and black holes sucking the gs from their companions. However, a star loses mass before it becomes a neutron star so I don't understand why it afects its neighbor more when it is a neutron star than when it was a regular star.

Homework Statement If a neutron star were bright enough to see its surface with a telescope, we'd be able to see not just the hemisphere facing toward us but also part of the far hemisphere. Explain why and estimate the latitude above which the far side could be seen. Homework Equations...

Dear all I have done some studies trying to understand the relation between the QCD theta angle and neutron electric dipole moment. General, the QCD vacuum produces the term L_{\theta} = \theta g_s^2\: G_a^{\mu\nu} \, G^a_{\mu\nu} this I can derive! I have studied Srednicki ch 93, Ramond...

Homework Statement Moderating a Neutron In a nuclear reactor, neutrons released by nuclear fission must be slowed down before they can trigger additional reactions in other nuclei. To see what sort of material is most effective in slowing (or moderating) a neutron, calculate the ratio of a...

What causes the neutron to have a magnetic moment , and is it paramagnetic or diamagnetic.

How can you measure the mean density of a neutron star if your only told its mass is three times that of the Sun?

Homework Statement What is the de Broglie wavelength of a neutron whose kinetic energy is equal to the average kinetic energy of a gas of neutrons at temperature T = 17 K? Homework Equations lambda = h/p = h/mv. The Attempt at a Solution Well first I tried taking the h =...

Does a moving neutron have an electric field ?

Homework Statement I have an assignment question that asks the me to look up the partial mass attenuation coefficients for Beryllium for Rayleigh Scattering, Compton Scattering, the Photoelectric Effect, and Pair Production in both the nuclear and electron fields on the NIST database for...

Hi guys, I am trying to calculate the macroscopic cross section (scattering and absorption) for high energy neutrons between 1 MeV and 10^7 MeV in Silicon. I am using the macroscopic cross section to determine the mean free path. To calculate the macroscopic cross section, i need to know the...

Neutrinos can pass through solid objects like the Earth easily, and a light-year of lead would only stop half of them from passing through. What about something very dense like a white drawf or neutron star? How readily can neutrinos penetrate that? What % flux reduction would be achievable...

Homework Statement Calculate the energy released in the alpha neutron reaction for beryllium. The mass of beryllium is 9.012183u. ^{4}_{2}He + ^{9}_{4}Be \rightarrow ^{1}_{0}n + ^{12}_{6}C Homework Equations The Attempt at a Solution Tried finding the total binding energy for both...

"neutron collides elastically with a helium nucleus" Homework Statement 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 rebound at an angle θ'2 = 40° from the neutron's initial...

Edit: nvm

Hi all. I am going to be doing an experiment involving neutron scatter. I am going to be firing fast neutrons into water and then detecting the thermal neutrons scattered. I am also going to look into thermal neutron capture where the hydrogen atom captures the thermal neutron and gives off a...

Despite sharing similar physical properties(neutron and proton having little variation in masses, protons and neutron being made up of quarks, both elementary particles are held together by the strong force) why is the decay time for like a neutron 10 minutes and the decay time for like a...

Hi, I did some calculations and I worked out the density of 1 neutron to be about 3.19887549*10^57 kg/m^3. However, I want to know if the method I used is correct. Density = mass/volume, correct? If this is true, then Density = [mass of neutron]/[volume of neutron] I found the volume of a...

Hi What is the best book about neutron scattering and diffusion? Regards

Here's a question. Why does slow neutron is most likely to cause a nuclear fission in Uranium 235, compare to a fast neutron?

I have two nuclear engineer related questions, please bear with me. 1. Why is hydraulic material (like water) is good to shield against neutrons? Why not high Z material like lead? 2. In cross section vs. energy of the nuclei, the curve of the graph undergoes 1/E relationship until it hits...

Can someone explain what "hardening" of a neutron spectra means?

Straight forward question. What would prevent the process of a giant lump of neutrons from forming a stable nucleus?

a) I need a simple description of how a Neutron Generator is built and how it works. b) Where can I see a picture of what a Neutron Generator looks like? c) What is a Plasma Focus (PF) Neutron Generator? d) Is PF the only type of Neutron Generator or are there other types?

when two neutron stars collide, do they creat both a balck hole and release gamma rays or does it happen in stages?

Homework Statement Assuming a neutron star is made from an incompressible material, what is the hydraulic pressure 50m below the surface? Mass = 1.98x10^30kg Radius = 10km 2. The attempt at a solution g=GM/r^2 = (6.67x10^-11 x 1.98x10^30)/ 10000^2 = 1.32x10^12 m/s^2 P=P_{0} + \rhogh Pa...

Homework Statement A neutron with kinetic energy T= 2mc^2 (m=rest mass),strikes another stationary neutron.What will be the combined kinetic energy of both the neutrons in the frame of their centre of inertia and the momentum p of each neutron in that frame.what is the velocity of the...

The binding energy for nucleon in a light atom (like deuterium) is lower than the binding energy for nucleon in a heavier, more stable element like iron. Suppose you remove the neutron from the light atom, and allow it to conjoin (by neutron capture) with an element that had an atomic number...

I have a problem here that has me a bit suck: In scattering between incident neutrons and target protons at rest, show that the angle between the two scattered particles is always 90 degrees. I have set up the conservation of energy and momentum equations and have: Energy: Tn=T'n+Tp...

Hi, here's the problem: "a neutron at rest decays into a proton with a decay energy of 0.78MeV. What is the maximum kinetic energy of the proton left behind?" here's what I've tried: In this decay, I assumed that although it's not mentioned, there would be something negatively charged...

Homework Statement If you were given 4 cookies, each emitter different ray 1)Alpha, 2)Beta,3) Gamma , 4)neutron You have to make decision of the following: a)eat one of the cookies b)dispose one of the cookies at storage facility called WHIP c)put one of the cookies in your pocket...

Homework Statement 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 rebound at an angle θ'2 = 41° from the neutron's initial direction. The neutron's initial speed is 6.2 x10^5 m/s...