Scattering Definition and 919 Threads

  1. W

    Compton Scattering; Relation between scattering angles

    Homework Statement Show that the scatter angles of the photon (θ) and electron (Φ) in the Compton effect are related by the relation: ##cot (θ/2 )=(1+\frac{hf}{mοC^2}) tan(Φ) ## Where f is the frequency of incident photon 2. The attempt at a solution I wrote down the equations of conservation...
  2. D

    Mechanism for extinction by scattering?

    Let's say you have a monochromatic laser beam directed towards a light sensor. As you move the sensor away from the laser, the intensity read by the sensor will decrease because of scattering on air molecules (extinction). Since intensity is proportional to the square of the E-field amplitude of...
  3. Glacier Studio

    Comprehensive Particle Scattering Table

    For particle physics research reference and education purposes, it's often convenient to have comprehensive particle scattering tables and Feynman diagrams at hand for analysis. May I ask whether there is a web site, app, or ebook that dynamically generates comprehensive scattering tables for...
  4. Anithadhruvbud

    Differences between dispersion and scattering?

    What makes dispersion be different from scattering? What exactly is the definition of scattering? Google says it is to deflect or diffuse.how can deflection be a synonym for scattering? How are they related?
  5. G

    Energy of scattering photon and emitted electron

    Homework Statement Photon of energy E=0,3MeV is scattering at an angle \phi=\frac{2\pi}{3}. Calculate the energy E' of scattered photon and emitted electron. Homework Equations -Compton effect The Attempt at a Solution By Compton effect...
  6. S

    Thomson scattering and radiating power

    I have a question about Thomson scattering from an electron hit by an incident em plane wave. The derivations that I have found all state the same thing. You have an electron in the origin at rest as the initial condition, the incident plane wave is linearly polarized towards z with amplitude...
  7. A

    Derivation of Rutherford Scattering - angular momentum

    Homework Statement I am trying to show that as the alpha particle is being scattered, the angular momentum magnitude at point M is m r^2 \frac{d \phi}{dt}. Diagram: Homework Equations Linear Momentum: ##\vec L = \vec r \times \vec p ## Repulsive Coulomb Force: ##\vec F = \frac{k 2Ze^2}{r^2}...
  8. FrancescoS

    S-matrix element for forward scattering and amputed green fu

    I'm studying dispersion relations applied as alternative method to perturbation theory from Weinberg's book (Vol.1) Let's consider the forward scattering in the lab frame of a massless boson of any spin on an arbitrary target ##\alpha## of mass ##m_\alpha>0## and ##\vec{p}_\alpha = 0##...
  9. I

    Inelastic scattering on a two level atom

    Homework Statement Consider a scattering problem that is described by the Hamiltonian . The target is prepared in the lower level. The kinetic energy of the incident particle is Ev. Find the transmission as a function of energy. Homework Equations . The Attempt at a Solution I tried going at...
  10. S

    Calculating the Cross Section for Rutherford Scattering

    Homework Statement Calculate the cross section for the scattering of a 10 MeV alpha particle by a gold nucleus (Z=79, A=197) through an angle greater than a) 10 degrees b) 20 degrees c) 30 degrees. Neglect Nuclear recoil. Homework Equations...
  11. CassiopeiaA

    Exploring the Mechanics of Photon-Photon Scattering in Particle Collisions

    Why do particles scatter in particle-particle collision while photons don't in photon-photon collisions, assuming that photons don't have enough energy to create particle anti-particle pairs?
  12. S

    Relation between cross section, scattering angle and KE?

    I'm trying to figure our the relation between cross section, scattering angle and KE? I'm doing a few exercises where I've been given kientic energy and scattering angle and have to calculate the cross section. Cross section is in units of Barns (m2), and KE is 1/2 kg*m2*s-2, but I can't seem...
  13. S

    Rutherford Scattering Trajectory

    Homework Statement Carbon scatters on a proton. What is the limit of the angle of scattering? I'm not really sure where to start this question. I know it has something to do with Rutherford Scattering and impact parameter. Homework EquationsThe Attempt at a Solution
  14. carllacan

    What determines the Compton scattering angle?

    Hi. I've been reading about Compton scattering and I don't understand what determines the angle at which the electron and photon are scattered. Is it a quantum process, and therefore the value of the angle is "random"? If it is a quantum process, is there any theory that gives the probability...
  15. S

    Simple calculation of Compton scattering in string theory

    Hallo. So the other day I reviewed a bit of quantum field theory and went through the Compton scattering calculation. To no ones surprise it was fairly simpel if you have a nice list of identities for rewriting the base results from the Feynman diagrams. See for exaxmple section 5.3 in...
  16. Aaron young

    Reworking of the Drude model using scattering statistics

    Homework Statement The problem I have been set is to rework the Drude model using clearly defined scattering statistics. Homework Equations The Drude model as we have been given it is in terms of momentum \vec{p}(t+dt)=(1-\frac{dt}{\tau})(\vec{p}(t)-q\vec{E}(t)dt)+(\frac{dt}{\tau})(0) Where...
  17. H

    Difference between 2-point and 4-point function in QFT

    As I understand it, the 2-point fnuction is for 1 particle incoming, 1 particle outgoing. The 4-point function is for 2 particles incoming, 2 particles outgoing. Is this correct? So an N-point function describes N/2 incoming particles and N/2 outgoing particles? Thanks!
  18. G

    How Does Neutron Scattering Reveal Anomalies in Phonon Dispersion Curves?

    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...
  19. N

    How is Equation 5-82 Derived from 5-79 in Optical Waveguide Theory?

    Homework Statement I have a problem understanding derivation of particular equation in a textbook on Optical Waveguide Theory (Snyder, Love) - see attached. The equation 5.79 is the starting point. Explanation of 5-80 are clear and derivation of 5-81 likewise. I am stuck, however with 5-82...
  20. J

    Exploring Electron Scattering in Crystalline Nickel Foil

    Homework Statement A beam of electrons with kinetic energy 50 eV is fired at a 100 nm thick crystalline nickel foil. (a) Calculate the speed of the electrons in the beam.(b) Based on your answer to part (a), state, with justification, whether classical (Newtonian) mechanics correctly...
  21. N

    Dirac-Delta Potential (Scattering)

    Homework Statement Say there exists a delta potential V(x) = α(x-L). Solve the eigenvalue problem to yield the energy eigenstates. Say a quanton is in an initial state given by Ψ(x)=Aeikox at t=0. What is Ψ(x,t)? Homework Equations Schrodinger Eqn. The Attempt at a Solution I solved the first...
  22. J

    B-particles inappropriate for scattering experiment

    Homework Statement 2. The attempt at a solution I thought because they are negatively charged and so they will get attracted to the positive nucleus, and also because they are too small, but they are not acceptable. The answer is that they have a range of energies / they are deviated by...
  23. RJLiberator

    Misconceptions about Bragg scattering and how it works

    Homework Statement Briefly describe how diffraction through a crystal lattice could be used to isolate a single wavelength from X-rays of many wavelengths. Homework Equations Bragg's equation: 2dsin(Θ)=n*λ The Attempt at a Solution Pretty fundamental question for the lab that I am about to...
  24. S

    How is the frequency unchanged in elastic wave scattering with a crystal?

    it makes sense that with an inelastic scattering process, a wave approaches a crystal, and then some energy is imparted to the phonons, so that the outgoing wave has a different frequency from the incoming wave. However, with an elastic scattering process, the frequency is unchanged-- how does...
  25. kelvin490

    Quesitons about scattering of light

    I have several questions about the scattering of light. Air molecules scatter sunlight and makes the sky blue, many books say that the air molecules are oscillated by E field and so they becomes sources of EM wave. Is it because the air molecules have charges? I wonder if air molecules or...
  26. K

    Dimensional analysis on equation including scattering length

    Hi all, I post a question about the dimension of wave function in position space before and people help me to identify that the unit of wave function should be in the unit of ##\text{m}^{-1/2}##. I am verifying that by doing the dimension analysis on Schrodinger equation...
  27. K

    Thermal Emission and Scattering (Mie or Rayleigh)

    From a book intro I've been reading, Scattering, Absorption and Emission of Light by Small Particles by Mishchenko, it states that when incident light hits a particle, that particle may absorb light, scatter light or emit the light. Excerpt: Can anyone explain to me, on a physical level, the...
  28. D

    Classical Scattering Formalism

    So the standard way to introduce scattering classically is through the two body problem for a central force where we move to the centre of mass reference frame and all the dynamics is explained by a one body problem for the separation vector ##r_{12}=r_1-r_2## with a reduced mass ##\mu=\frac{m_1...
  29. D

    Goldstein Central Force Repulsive Scattering

    On page 108 in Goldstein 3rd edition in the paragraph after equation (3.94) he says that ##\psi##` can be obtained from the orbit equation (3.36) using the limits as ##r_0=\infty## ##r=r_m## which the distance of closest approach and ##\theta_0=\pi## which is the initial direction. So looking...
  30. T

    PreReqs for Quantum Scattering

    Hi everyone, What chapters in Shankar do I HAVE to read before I can understand Scattering Theory?
  31. Y

    Partial width for elastic scattering

    Homework Statement A beam of neutrons hit a target of heavy nuclei with spin ##J_N = 0## with resonance when the energy of the incident beam is 250eV, in the cross section distribution with a maximum of 1300 barns. The width of the maximum is 20 eV. Find the partial width of resonance for the...
  32. R

    Axion thrust by enhanced scattering

    Axions in theory are uncharged, spin 0, very light particles, and have a very small scattering cross section when interacting with photons. But there is a very interesting article about a strong enhanced scattering of neutral particles. "Resonant radiation pressure on neutral particles in a...
  33. Z

    Researching Pi-N Scattering and Virtual Photon Excitation of Neucleons

    Pi-N scattering is useful for research on neucleon resonance.But pi meson is not stable,how could it be controlled to collide with a neucleon? While,virtual photon is also used to excite neucleon,it is internal line particle,which is determined by a reaction,so how hard could it be controlled...
  34. Avatrin

    Conservation of momentum in compton scattering

    Hi I recently got some weird feedback on homework. It said that "..momentum is only conserved componentwise..". The problem involved Compton scattering, and I had used p_{\lambda,1} = p_{e,2} + p_{\lambda,2} to find p_{e,2} for collision between an electon and a photon. I had used the...
  35. K

    Scattering amplitude, link between quantum mechanics and QFT

    In quantum mechanics, we can define the scattering amplitude f_k(\theta) for two particles as the coefficients of an outgoing spherical wave. More precisely, the asymptotic behaviour (when r\rightarrow\infty) of a wave function of two scattering particles, interacting with some short range...
  36. U

    2D problem of nearly free electron model

    Homework Statement (a) Find energies of states at ##(\frac{\pi}{a},0)##. (b) Find secular equation Homework EquationsThe Attempt at a Solution Part(a)[/B] In 1D, the secular equation for energy is: E = \epsilon_0 \pm \left| V(x,y) \right| When represented in complex notation, the potential...
  37. Harry Atkinson

    Compton Scattering: Find scatter angle of electron & Vf

    Homework Statement http://oi58.tinypic.com/2zitybl.jpg Homework Equations As above The Attempt at a Solution [/B] Rearranging the above equations to remove unknowns, finally substituting new equations into the compton effect equation. Will post up next page as I fill it, - is it acceptable...
  38. A

    Mass dependent multiple scattering

    What is the dependence between multiple scattering (Moliére formula) and the mass of incident particles? I'm reading on my book: "the effect of multiple scattering is generally small for heavy charged particles" but I really can't find a correlation with mass in the Molière formula, while the...
  39. U

    Form Factor - Simply take the real part?

    Homework Statement Show that the Form factor is ##\frac{3(sin x - x cos x)}{x^3}##. Homework EquationsThe Attempt at a Solution [/B] I know that the form factor is simply the Fourier transform of the normalized charge density: F(q) = \int \frac{\rho}{Z} e^{-i (\Delta \vec k) \cdot \vec r}...
  40. U

    What does this length represent?

    I was doing some calculations earlier and tried the ratio between a metal's fermi temperature ##T_F## and debye temperature ##\theta_D##: \frac{T_F}{\theta_D} = (6 \pi^2)^{\frac{1}{3}} \left( \frac{\lambda}{a} \right) where ##\lambda = \frac{\hbar}{2 m_e c}## and lattice spacing is ##a##. I...
  41. R

    Electron - Phonon scattering, deriving the contribution to

    ... electron transport. 1. Homework Statement Electron - Phonon scattering, derive the contribution to electron transport. Homework Equations Trig. The Attempt at a Solution Am I being REALLY stupid here, I can't see how the equation matches the triangle. If you resolve KF' doesn't KF'...
  42. U

    What Are the Calculations Behind Electron-Phonon Scattering in Copper?

    Homework Statement (a) Find fermi temperature and debye temperature. Calculate them for copper. (b) Show the scattering wave relation (c) What does ##\lambda## mean? Homework EquationsThe Attempt at a Solution Part(a) The fermi temperature and debye temperature is given by: T_F = \frac{\hbar^2...
  43. S

    How Does Changing Lattice Dimensions Affect X-ray Scattering Angles?

    Homework Statement We scatter a roentgen light with ##\lambda =\frac{2a}{\sqrt 7}## on a particle of dust of a crystal, with cubic crystal lattice as shown in the attached image. a) Calculate geometric structure factor. Calculate with cubic primitive cell. b) At which scattering angles do we...
  44. S

    Rutherford scattering - electromagnetic form factor

    Homework Statement Hi there. This is not really a problem, I am only trying to understand something but I simply can't. So Rutherford scattering says that $$ \frac{d\sigma }{d\Omega}=(\frac{Ze^2m}{8\pi \varepsilon _0 p^2})^2\frac{1}{\sin ^4(\Theta/2)}|F(q)|^2$$ where $$F(q)=\int \rho (\vec...
  45. thegirl

    Rutherford Scattering model geometry

    Hi, I was just wondering if someone could help clarify how pi - theta = phi? That is the link to the youtube video I was watching, the guys pretty good check him out if you want to learn how to derive the differential scattering cross section.
  46. K

    Understanding Scattering Length in Atom Interaction: A Comprehensive Guide

    Hi all, I am reading some materials on the scattering. There is simple model to consider atom as a rigid body but with radius replaced by the so-called scattering length. I didn't learn the scattering theory systematically but my understanding on the scattering length is the minimum separation...
  47. A

    Photoelectric effect and Compton scattering

    Homework Statement A photon with of 13600eV energy interacts with a hydrogen atom at rest and ejects the electron (photoelectrically) in the direction in which the photon was travelling. If 13.6 eV is required to eject the electron, find the speed of the photoelectron and the momentum and...
  48. U

    'Special' fourth order Feynman diagram Compton Scattering - Why is it allowed?

    I thought the fundamental electromagnetic vertex is Why is the following diagram below allowed? The 'special' feynman diagram for compton scattering ##e^- + \gamma \rightarrow e^- + \gamma## is
  49. F

    What is the difference between the scattering BC and PML?

    Hi, I want to know what is the proper boundary condition in COMSOL RF module to study optical interactions, Scattering BC and PML? or what is the difference between them? also I want to know if the rules are different for application of these two BCs in far-field and near-fields studies...
  50. M

    Elastic scattering of WIMPs off nuclei

    Hello, My problem is as follows I've tried differentiating to find the maximum and I've tried plotting E against m_{\chi} for a range of values and this did not suggest a maximum at m_N = m_{\chi}. Could someone explain why it is the case that the energy transfer is maximum when these masses...
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