Neutron Definition and 770 Threads

Hi, Does an Atom's Type have to do with the number of protons and neutrons it has? Or are they completely unrelated? Just curious. Thanks :)

Does the pressure within a neutron star compress the neutrons to a smaller size?

When the teacher is asking for the definition of "Neutron activation and moderation" does he mean it together or separate. I google the quoted word but it gives "Neutron activation analysis". Is this the same thing or do I look separately the word "Neutron activation" and then "Neutron moderation".

I have a liquid scintillator, the electronics system, and a beam of neutrons from a reactor. How do I calculate the neutron flux? Cold anybody give me a formula or equation? Not this equation: phi = n X v, where phi - flux, n = number of neutrons per cm3, v = velocity of the neutrons, because I...

Has anyone analyzed the process of Neutron formation and decay from the perspective of "information conservation"? Does anyone have any thoughts on what the results of such an analysis would be? What is the status of the observed evidence of reality in respect of whether one should conclude...

Homework Statement Calculate the number of white dwarf, neutron star and black holes the galaxy will have after 5Gyr of evolution. M<8(solar mass) for white dwarf 8(solar mass) < M < 40(solar mass) for neutron star M > 40(solar mass) for black hole Initial mass function is ξ(M) = AM-s...

I'm trying to make a LSC with U-238 (non-aqueous form) dipped in the scintillating cocktail to detect fast neutrons (no thermals or epithermals, only fast) from a Cf-252 source. How do I calculate the wavelength emerging from the cocktail (assuming U-238 does not react with the cocktail)? Also...

There is some discussion regarding the decay time of the neutron here for example. Has the decay time of the anti-neutron been predicted or seen to any degree of accuracy that could be compared to the decay times seen for the neutron? Is it expected to be the same?

Just wondering why to use negative hydrogen H- ion in spallation neutron source. I read the literature through http://neutrons2.ornl.gov/facilities/SNS/works.shtml , still not yet get the answer. If directly use proton, then still easy to accelerate, and no need to strip off the unwanted...

So a programme that I watched on tv was talking about neutron stars and they said that the neutron stars neutrons were formed by protons and electrons combining to make neutrons. I was just wondering, how does this work, in the field of the quarks in the proton and how they are effected by an...

Hello everyone, What is the average intensity of the background neutron radiation?

Hello everyone, Is it practically possible to detect a neutron source with an intensity of 0.1 Bq and each neutron having nearly 10MeV energies (and differentiate it from background neutron radiation)? If that's possible, what kind of equipment can be used? Do you need extremely sensitive and...

How durable are the neutron stars, ie how long can they last? Will they "evaporate" like black holes or something else will happen with them after a very long period of time (eons)? Or are they immortal? I'm asking because I have found nothing clear about the lifespan of a neutron star.

I am reading about mergers of a neutron star with a black hole and the association with GRB. While talking about the accretion disk, the paper I am reading says about the last stable circular orbit. Firstly I thought it was where the Roche limit lies, where mass transfer or matter ejection from...

I am wondering, if the sun is a fusion reactor, it should have an "atmosphere" of neutrons ? So presumably a craft with suitable fuel eg boron or uranium, in a close pass, would be able to use that to react with the fuel in a suitable drive ? Probably not good for humans - (!) but for an...

Now kindly pardon my ignorance but I hope one of you can explain to me how this can be possible. A rotating neutron star or pulsar have been observed to spin at between 10 to 700 times per second. Now before I proceed further I like to draw your memories back to the merry go round we played as...

Question in my textbook:- The wavelength of light from the spectral emmision line of sodium is 589 nm. Find the kinetic energies of electron and neutron at which they both have same de broglie wavelength. Logically, since light of same energy is falling on both then their kinetic energies must...

My wife and I attended the Perimeter Institute for theoretical physics. We watched the public lecture called: THE COSMIC GIFT OF NEUTRON STARS by VICTORIA KASPI. I thought it was a decent lecture (perimeter has had some outstanding ones in the past). On the way to work this morning I was...

Suppose a shield that is infinite in the y and z directions and of thickness 1 meter in the x direction is constructed of alternating layers of materials A and B. Will this shield attenuate a beam of neutrons with more or less or the same attenuation that it would if it were constructed of the...

Does this neutron star have an accretion disk?: https://en.wikipedia.org/wiki/IGR_J11014-6103#/media/File:Lighthouse_nebula.jpg

Could neutron star jets with velocity greater than 0.9c be caused by a mix of ultra-relativistic core material escaping the star? See this link: http://www.dailygalaxy.com/my_weblog/2015/08/neutron-star-jets-near-speed-of-light-rival-those-of-black-holes.html

Hello It seems to me that the nuclei have a flat elastic scattering cross section of neutrons, for neutron energies from eV to MeV. http://www.nuclear-power.net/wp-content/uploads/2015/11/Elastic-Scattering-Cross-section-light-elements-min.png I thought that maybe it was caused because the...

"Looking at time behaviour of neutrons in a reactor on time scales of both ~sec and ~days/months Start with fission process e.g. 235U + n -> 236U ->fission Usually divide into 2 Fission Fragments 10%-20% of fission emit a scission neutron (i.e. at time of scission)" I've heard...

Dear PF Forum, Just out of curiosity. What happens when an anti proton hits a 'normal' neutron? According to this: https://en.wikipedia.org/wiki/Proton https://en.wikipedia.org/wiki/Neutron A proton has 2 up quarks, 1 down quark A neutron has 1 up quark, 2 down quarks. 1. Does anti proton has 2...

What happens to the neutrons in a neutron star as it collapses Into a black hole?

Is there any good information about the chemical composition of relativistic jets from neutron stars? If the chemical composition of the jets was different from the accretion material it could shed light on the process that forms the jets.

A method of definitely distinguishing a neutron star from a possible stellar black hole is that it produces X-ray bursts, which have a sharp rise time and may last for an extended period. I had previously thought these occurred when hydrogen fell to the surface and was immediately fused to...

Could accreting material on a neutron star’s poles impact with enough energy to initiate fusion reactions, some of which escapes the star as ultra-relativistic jets?

OK so some stars evolve into neutron stars which I assume are so small (10's of kms) because ALL empty space is removed between the atoms.. absolute highest density possible? Now.. is a black hole larger (massive and in diameter) than a neutron star and called a black hole only because the...

When a large amount of plasma radiates greatly while accreting on a magnetized neutron star, where does the radiation ultimately get its energy from, the magnetic field and/or gravitational field? Without doing the numbers, if the magnetic field does the work against the gravitational field, and...

If a bubble of quark type matter formed near the core of a magnetized neutron star, what would happen to its shape? Would it elongate along the magnetic field lines? Could it burst out of the magnetic poles of the star?

I think this could be a good chance that we see how neutron stars form from White Dwarf mergers. The combined mass of the two are less that than required for a type Ia Supernovae. Won't they merge and collapse into a neutron star? What does everyone else think might happen. I want to be sure if...

Consider a monoatomic 1-D chain of atoms (only acoustic branch). What happens with the inference of the dispersion curve through neutron scattering? In one dimension, conservation of momentum dictates $$ k'=k+K_s $$, if k_s is the phonon momentum vector and we only consider processes where a...

Hello all, I could be looking at this the wrong way but here it goes: From what I understand, if a star collapses into itself to form a neutron star, it would become more compact, denser and heavier with a larger gravitational attraction. Now, if I understand correctly, the size of...

Homework Statement Calculate the de - Broglie wavelength associated with a neutron moving with energy of 2ev .( mass of proton mp= 1.67*10^-27 kg ) Homework Equations Wavelength= nh/ 2π KE = eVs = 1/ 2mv^2 eVs=hf Wavelength= v*f The Attempt at a Solution To calculate the wavelength at first...

In calculations of quantities in Neutron stars with degenerate matter is usual to set temperature zero. If I'm right it means that pressure of this matter is negligible against pressure due to Pauli principle. But what about situation when the matter is in neutron star locally compressed. How...

I'm curious, why does Helium-3 fission into H-3 and H upon neutron absorption? Surely the He-4 nucleus configuration is more stable? I get that the energy release may be what splits the nucleus, because it releases quite a lot of energy if it were to simply absorb the neutron.

In a neutron star gravity has overcome electron degeneracy pressure allowing the protons and electrons to combine into neutrons. But if that is the case, how do neutrons emit light if there are no electrons to swoosh the photons away? I have been thinking, and wonder if the surface (or "crust")...

Quarks join up with other quarks to form composite particles like protons and neutrons, but in the center of something like a nucleus, how do they know which quarks are in THEIR proton or neutron? When all the quarks are together and it becomes a "soup" of quarks, why doesn't it form things like...

I'm starting a new thread; it's not just about cyclotrons this time. The question is as follows: has anybody ever heard of or read about neutron production (=fusion reactions) when a beam of fuel nuclei, such as D+ or Li3+, is bent by a (strong) magnetic field, such as a bending magnet in an...

There tend to occur in accelerators and ion sources, when they are "run" on deuterons, fusion reactions with neutron production, due to collisions with residual gas in the chamber. Now, I wonder if the same phenomenon has been observed with cyclotrons when they are "run" with deuterons? Or...

If they are so insanely dense and their gravity is so mind-numbingly great, what prevents a neutron star from immediately collapsing into a black hole?

The answer according to my booklet is 1.6734×10-24 (g), but I don't understand how we got this answer. proton: 1.6725×10-24 neutron: 1.6748×10-24 electron: 0.0009×10-24 To get the mass, I added protons with neutrons, but I got 3.3473×10-24. What am I doing wrong?

Homework Statement A Helium 5 at rest decays into Helium 4 and a neutron. Mass of Helium 4 = 6.648 x 10^-27 Mass of Neutron = 1.67493 x 10^-27 Helium 4 has a momentum of 1.903 x10^-20 and Ek 2.723x10^-14Homework Equations E=mc^2 v= square root of (E2/m) The Attempt at a Solution I have found...

Dear PF Forum, I have question concerning neutron star and star just simply out of curiousity. 1. Can a star reach silicon burning stage then stop. It doesn't continue to iron burning stage. 2. Once a star reach iron burning stage, there's no stopping it to blast into supernova? Is supernova...

I've been trying to find a source for this somewhere, but I always end up with different sources explaining what holds protons and neutrons together in the nucleus of an atom. I know that the gluons hold them together, but I'm not sure exactly how they do this, and what type of transfers occur...

I'm a high school student reading through a book on the discovery of the Higgs boson, and, among several other things, there's one part that I don't understand completely. I understand that the Higgs field is what gives mass to lots of particles that would otherwise be the same without the...

why is each fundamental particle round

Do neutron star, pulsars, magnetars etc. have solar flares like the sun or do they have sun spots like the sun or do they have solar winds and if they do have any of those types of weather, what are they called?

Hi everyone. Most of what I've read on thermal neutron cross sections talks only about what isotope makes up the neutron target. Likewise, all of the cross sections listed on Sigma: http://www.nndc.bnl.gov/sigma/index.jsp?as=9&lib=endfb7.1&nsub=10 ... are broken down just by isotope. However...