Scattering Definition and 919 Threads

Homework Statement The Spacing between the Na and Cl atoms in table salt (NaCl) is ##d=2.82x10^{-10}m##, which was first deduced from Bragg scattering. For an experiment where X-rays of energy 20 eV are produced, what are the corresponding Bragg angles below ##90^{\circ}## for scattering from a...

Hello, Ok, so I’ve been searching about this for a while and there seems to be a difference in explanations that confuses me. What concerns me is the exact detailed physical mechanism that makes particles cause a scatter of a photon and an emission of a photon. The Wiki page about scattering...

Hi. I'm trying to model the attenuation (extinction) of a weak laser through a gas sample using the Beer-Lambert law. I've found that the attenuation cross section can be written as the sum of both a scattering and absorption cross section, however I'm having difficulty finding a source that...

I'm a Physics undergraduate at University and in my labs module I had to recreate the Rutherford Scattering experiment. The basic setup was similar to this: My problem is that this setup only records data in one plane and not 3D. In reality the particles are scattered in a sort of cone...

I'm told that the MnO crystal resembles in structure that of NaCl (FCC) with lattice constant a, and am first asked to write a general expression for the position vector Rj of the ion j in the unit cell of MnO. I am then asked to find the vector K for MnO in order to use the relation...

In order to compute the scattering probability that two particles of type 1 (associated to ##\phi_1(x)##) which come from the far past with the momenta ##p1## and## p2##, to scatter and evolve into two particles of type 2 (associated to ##\phi_2(x)##) with the momenta ##p3## and ##p4## , I am...

Hi i am trying to understand Borh's scattering but i need article that will teach me step by step. Do you know any?

I have tried to solve a scattering problem of two particles in one dimension, following the T operator theory, after to write the system in the center of mass reference. I have used the square potential \begin{equation} U(x) = \left\{ {\begin{array}{cc} U_0 & 0 < x < a \\ 0 & \rm{Otherwise}...

Homework Statement [/B] An unpolarized ruby laser operated at 0.7 μm is projected vertically into a clear sky to investigate the density of the atmosphere. A detector located 10 km from the base of the laser is used to receive the flux density scattered from the laser beam by air molecules...

I'm looking at Aitchison and Hey's QFT book, trying to verify Eq. 8.27 (which is in fact problem 8.2). It asks us to verify that the matrix element for the scattering of a charged spin zero particle (s^+) is <s^+,p'|j^\mu_{em,s}|s^+,p> = e(p+p')^\mu e^{-i(p-p')\cdot x} where...

It has been demonstrated that it is possible to make humans hear sounds using waves. Abstract From Journal of Applied Physiology Is there a practical method for shielding? I mean using materials for simple attenuation, and/or altering characteristics of waves (frequency, phase and/or amplitude).

Hi everyone! What is the difference between coherent and elastic scattering. Maybe the elastic scattering implies that there is not loss of energy, whereas the coherent scattering implies that the wavelength of a ray (or rays) is the same before and after the scattering? Thank you in advance.

It is mentioned in my Textbook that if alpha-particle has large impact parameter, it gets scattered through small angles and vice versa. I understand that impact parameter is defined as the perpendicular distance between the path of a projectile and the center of the nucleus. I am unsure how...

Homework Statement In electron proton scattering, ##\int_0^{1} F^p_2(x)dx = 0.18## For the neutron in electron deuteron scattering, ##\int_0^1F^n_2(x)dx = 0.12## Therefore determine the ratio ##\frac{\int_0^1xu^p_v(x)dx}{\int_0^1xd^p_v(x)dx}##. Homework EquationsThe Attempt at a Solution...

For centuries, scientists argued whether light was waves or particles. Light scattering with other light would favor the particle concept. Today we know both models are wrong, but quantum electrodynamics also predicts this scattering - just with an incredibly tiny rate, so it has never been...

Homework Statement An electron collides with a particle with mass M at rest and scatters elastically through an angle θ (assume electron mass negligible). Show that the fraction of energy lost by the e- is: (Ee - Ee')/Ee = 1/[1+ Mc2/Ee(1-cosθ)] Homework Equations Conservation of Energy: Ee +...

Homework Statement This is the problem 3.34 from Goldstein, 3rd Edition: Consider a truncated repulsive Coulomb potential defined as V=k/r, for r>a and V=k/a, for r<=a. For a total energy E>k/a, obtain expressions for the scattering angle ##\Theta## as a function of ##s/s_0##, where ##s_0##...

At next to leading order, a photon may couple to gluon via means of a quark loop insertion. Consider the process $$ \gamma(k_1) + g(p_1) \rightarrow \gamma(k_2) + g(p_2)$$ Apparantly there are eight diagrams at one loop contributing to this process and two are zero on grounds of colour...

Hello, I'm studying the setup of distributed Brillouin sensor (using fibre optics) and don't quite understand the purpose of EOM in the sensor. It says that "to generate both the pump and the probe waves from a single physical light source by using an electro-optical modulator (EOM)", but since...

I am reading through Bailin and Love's argument (see P.151-152 of 'Introduction to Gauge Field Theory') that as ##Q^2 \rightarrow \infty##, we probe the product of the two electromagnetic currents appearing in the hadronic tensor for DIS on the lightcone. I will write out the argument here and...

Hi, I have to make a work about what are the major components of Mie scattering from a quantum physics point of view. Unfortunately, from the research I did I only came up with how Mie scattering can be derived from the Maxwell equations. I must probably using the wrong research words, and I...

So I'm studying scattering and size parameters now, I've come to understand that the sky is blue because the size parameter is such that it's an excellent "scatterer" of blue-violet visible light, and horrible at red-orange, that let's pass, and such the sun is yellow within the Earth. I've also...

origin page : http://www.physicspages.com/2012/08/08/finite-step-potential-scattering/ No quite understand how the solution come from this equation

Is there some way to - from an intuition standpoint - justify the fact that there should be a factor of ##a^{6}##, (where ##a ## is the particle diameter) in the Rayleigh Scattering formula? I've seen a few sources hint that there should be. I can follow the derivation from e.g a Lorentz atom...

I read many times that the early universe was opaque foremost because of the scattering of photons off free electrons (Thomson scattering). Why is the scattering off free protons not equally important? Btw, the same they say about stars. Photons within stars need a very long time to get out of...

Hi I am revising for an exam and am a bit confused with Rutherford Scattering - Finding the cross section (is the cross section different to the differential cross section?) - Finding the solid angle. So here is a past question: A beam of 6MeV alpha particles is incident on a platinum foil. A...

Homework Statement [/B] (Note: this is not strictly homework, but it is related to one course I'm doing, and I can't find a useful solution anywhere) Find the analytical expression for the scattering cross section of two longitudinally polarized electrons at tree level. Homework Equations...

Homework Statement This is just a simple proof of substitution, but after one day struggle, I still can't get where that minus sign appear. Homework Equations Here is the equation: $$ (p_1 - p_3)^2=-(\mathbf p_1 - \mathbf p_3)^2$$ where ##p_1=(E/c,\mathbf p_1)## and ##p_3=(E/c, \mathbf p_3)##...

Homework Statement Two identical charged particles, each of mass m and charge e, are intitialy far apart. One of the particles is at rest at the origin, and the other approaching it with velocity v along the line x=b, y=0 where b=e^2/2 \pi \epsilon_0 mv^2. Find the scattering angle in the CM...

I was wondering if it is possible to image the motion of individual air molecules? What I am picturing is using a laser to illuminate a volume of air, and using scattered light to measure the velocity of individual air molecules through the doppler shift of the scattered light. It seems that...

Hi, I read in some papers which say the unit of atom scattering factor is e/atom. what is the meaning of that? thank you!

Hello, what is the physical meaning of the scattering length? I know this question was discussed here before but I still have questions. This quantity is listed in table 1 of this paper: http://rpd.oxfordjournals.org/content/132/1/29.full.pdf. I need to clarify a few things: does scattering...

Homework Statement After undergoing through 90° compton scattering, the fraction of energy lost by photon is a) 10% b) 20% c) 50% d) zero e) none of these Homework Equations ∆λ= h/moc (1-cosΦ) The Attempt at a Solution What i m doing is that, i get scattered photon energy and subtracting...

According to Tong there are two Feynman diagrams for nucleon-nucleon scattering in the interaction of the complex and real scalar fields, but I can draw another diagram where the p1 and p2 particles enter a vertex and the p1' and p2' particles go out of another vertex (linked to the first one by...

Homework Statement A low-energy particle collides elastically with a stationary particle of the same mass. The angle between the subsequent paths of both particles are 90 degrees. But when a high-energy proton collides with a stationary proton, the angle between the two paths is not 90 degrees...

Homework Statement Onto an Aluminium 50μm thick plate, we send a beam of alpha particles with unknown kinetic energy. the cross section of the beam is 2cm2, density 1013 / scm2 . Whats the kinetic energy of the particles if every second we sense 105 scattered particles between the angles 40°...

Hello I am a lower-intermediate user of MCNP and I do not know how to obtain the diffusion coefficient (or maybe the angle of scattering) using tallies. I also have read a paper (Multigroup Scattering Matrix Generation Method using Weight-to-Flux Ratio Based on a Continous Energy Monte Carlo...

From what I understand, a photon of "sufficient" energy will interact with a free electron such that the recoil electron receives part of the energy of the photon, and the scattered photon has a Doppler shift (change in wavelength). If the scattered photon still has "sufficient" energy, Compton...

Hi everyone, with this thread I kindly seek for advice from more experienced people to hear as many opinions as possible. I will try to explain the situation clearly: I am doing a 4 years Msci programme in Theoretical Physics, in which I almost completed the third year. During the third year...

In a typical collider experiment, two particles, generally in approximate momentum eigenstates at ##t=-\infty##, are collided with each other and we measure the probability of finding particular outgoing momentum eigenstates at ##t=\infty##. Firstly, what does it mean for the particles to be in...

The normalized differential quantum-field-theoretic probability ##dP## of scattering is given by ##dP=\frac{|\langle f |S|i\rangle|^{2}}{\langle f|f\rangle\langle i|i\rangle}d\Pi,## where ##|i\rangle## is the initial state, ##|f\rangle## is the final state, ##\langle f|S|i\rangle## are the...

Hello all, I'm just doing some practice for an upcoming exam and came upon this question in my notes: One experimental way to generate very high energy photons is to ”collide” a laser beam against an electron beam, the photons that recoil in the direction parallel to the electron beam will have...

Homework Statement A 0.7MeV (E°) photon scatters off a free electron such that the scattering angle of the photon is twice the scattering angle of the electron (θ=2φ). Determine the scattering angle for the electron. Homework Equations λ' - λ° = h/(mec)(1-cosθ) E = hc/λ ρelectron = mev /...

Homework Statement In a fixed target experiment a particle of mass M and kinetic energy T strikes a stationary particle of mass M. By evaluating s, t and u in the laboratory frame and using the above relation, or otherwise, show that the kinetic energy T' of the particle scattered elastically...

I'm trying to visualize the effect of the inverse square law, not on a direct source of light, but on scattered light carrying visual data, such as that responsible for our everyday sight of things as well as our images of Earth from satellites. It seems to me that it should be true that, while...

Hi, I really don't have a clue to solve this. I tried something like the dirac function identity: But then I saw it's dk' not dk' and couldn't got it straight. Can someone help me with this?

Homework Statement 1) Calculate the angular diameter distance to the last scattering surface in the following cosmological models: i) Open universe, ΩΛ= 0.65, Ωm = 0.30 ii) Closed universe, ΩΛ = 0.75, Ωm = 0.30 ii) Flat universe, ΩΛ = 0.75, Ωm = 0.25 Describe how the CMB power spectrum...

We know that the solution of the schroedinger equation for a free particle in position representation is a plane wave: \psi(x)=Ae^{ikx}+Be^{-ikx} which means that the particle has a probability to move either to the left or to the right. "Now let's take the potential step problem. V(x)=0 for...

Homework Statement 1) Calculate the angular diameter distance to the last scattering surface in the following cosmological models: i) Open universe, ΩΛ= 0.65, Ωm = 0.30 ii) Closed universe, ΩΛ = 0.75, Ωm = 0.30 ii) Flat universe, ΩΛ = 0.75, Ωm = 0.25 Describe how the CMB power spectrum...

Hello everyone, Still working on my reading of Weinberg's Lecture notes on QM book. At one point, the following integral $$\int d^3 xd^3 x' V(\vec{x~}) V(\vec{x'}) / |\vec{x~} - \vec{x'}|^2$$ has to be computed in the case where ##V(r) = -e^{-r/R}/r##. This reminds me of retarded potentials...