Scattering Definition and 918 Threads

Scattering is a term used in physics to describe a wide range of physical processes where moving particles or radiation of some form, such as light or sound, is forced to deviate from a straight trajectory by localized non-uniformities (including particles and radiation) in the medium through which they pass. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection. Reflections of radiation that undergo scattering are often called diffuse reflections and unscattered reflections are called specular (mirror-like) reflections. Originally, the term was confined to light scattering (going back at least as far as Isaac Newton in the 17th century). As more "ray"-like phenomena were discovered, the idea of scattering was extended to them, so that William Herschel could refer to the scattering of "heat rays" (not then recognized as electromagnetic in nature) in 1800. John Tyndall, a pioneer in light scattering research, noted the connection between light scattering and acoustic scattering in the 1870s. Near the end of the 19th century, the scattering of cathode rays (electron beams) and X-rays was observed and discussed. With the discovery of subatomic particles (e.g. Ernest Rutherford in 1911) and the development of quantum theory in the 20th century, the sense of the term became broader as it was recognized that the same mathematical frameworks used in light scattering could be applied to many other phenomena.
Scattering thus refers to particle-particle collisions between molecules, atoms, electrons, photons and other particles. Examples include: cosmic ray scattering in the Earth's upper atmosphere; particle collisions inside particle accelerators; electron scattering by gas atoms in fluorescent lamps; and neutron scattering inside nuclear reactors.The types of non-uniformities which can cause scattering, sometimes known as scatterers or scattering centers, are too numerous to list, but a small sample includes particles, bubbles, droplets, density fluctuations in fluids, crystallites in polycrystalline solids, defects in monocrystalline solids, surface roughness, cells in organisms, and textile fibers in clothing. The effects of such features on the path of almost any type of propagating wave or moving particle can be described in the framework of scattering theory.
Some areas where scattering and scattering theory are significant include radar sensing, medical ultrasound, semiconductor wafer inspection, polymerization process monitoring, acoustic tiling, free-space communications and computer-generated imagery. Particle-particle scattering theory is important in areas such as particle physics, atomic, molecular, and optical physics, nuclear physics and astrophysics. In Particle Physics the quantum interaction and scattering of fundamental particles is described by the Scattering Matrix or S-Matrix, introduced and developed by John Archibald Wheeler and Werner Heisenberg.Scattering is quantified using many different concepts, including scattering cross section (σ), attenuation coefficients, the bidirectional scattering distribution function (BSDF), S-matrices, and mean free path.

View More On Wikipedia.org
  1. J

    Atmospheric Scattering Problem

    Hello, So I have a scenario where the Earth's atmosphere, instead of scattering blue light from the sun, actually scatters green light based on Rayleigh scattering. I know that the sky will therefore appear green, but how will the sun appear? I reasoned the sun will be magenta using...
  2. F

    Photon Scattering: Find Wavelength of Incident Photon

    Homework Statement A photon scatters in the backward direction (\theta= 180) from a free proton that is initially at rest. What must the wavelength of the incident photon be if it is to undergo a 10.0% change in wavelength as a result of the scattering? Homework Equations...
  3. B

    General angular momentum question (rutherford scattering context)

    ... if you consider something simple momentum conservation, like in the case of a bullet, if you consider the system of the gun and the bullet, the momentum is zero before and after the shot is fired. same for collisions etc... however when you consider something like a deflection in...
  4. C

    A decent intermediate treatment of central forces and scattering?

    Hiya. I'm revising for a classical mechanics first year exam, and the lecture notes on central forces are less then ideal. I'm looking for a fairly simple treatment of the subject with especial regard to circular motion, bound and unbound orbits, binary systems, kepler's laws, distance of...
  5. N

    Explanation of particle physics phenomenon - multiple Coulomb scattering

    Homework Statement Hi 1) I read the following article: http://pdg.lbl.gov/2005/reviews/passagerpp.pdf On page 12 of the .pdf there is a figure, figure 27.8, which shows how a charged particle deviates from it's path when scattered by the Coulomb force that comes from the nuclei of the matter...
  6. X

    Mastering Compton Scattering Squaring for Scientists

    Homework Statement How to square this : (Pi+m.c-Pf)^2 ? Homework Equations The Attempt at a Solution I did : Pi^2 + m^2*c^2 + Pf^2... but then I don't know the rest of the completion.. please help me.. Thank you in advance..
  7. D

    Compton Scattering Effect: Max Kinetic Energy

    Okay, so I have two questions, both pertaining to the Compton Effect. Homework Statement Evaluate the maximum kinetic energy for a recoiling electron that is struck by a photon with momentum 0.04MeV/c Homework Equations Maximum Kinetic energy: E_{k} = \frac{hf}{1 + (mc^{2}/2hf}...
  8. Q

    Two questions concerning scattering in QED

    1. Are there possible (4th order)process of "decay of photon" \gamma\rightarrow 3 \gamma with one-photon initial state and 3-photon final state? Intuition tells me there are no such processes. But because of crossing symmetry of scattering amplitude one can argue that such processes should be...
  9. A

    Compton Scattering Using Mandel-Stam Variables

    Homework Statement Not homework, just for fun. I want to derive Compton Scattering equations using Mandel-Stam variables as opposed to the way that I have done it in class using the usual energy and momentum conservation Homework Equations (p_\mu+p_{ei}_\mu)^2=(p'_\mu+p_e_\mu)^{2}=s p is the...
  10. C

    Scattering in water or atmosphere

    hi, i want to know why scattering can occur when the light beam meet the particle, dust in atmosphere or molecules in water ..., but why not when they meet the glass surface and let the electrons in the glass surface be scattered? can anyone kindly help me, and tell me more about this ? thanks...
  11. L

    Differential Cross Section for scattering by Hard Sphere

    Problem Determine the differential and total cross sections for scattering from a "hard sphere" of radius R ("hard" means impenetrable). Relevant Formulae \sigma (\Omega) d \Omega = \frac{number \ of \ particles \ scattered \ into \ solid \ angle \ per \ unit \ time}{incident \ intensity}...
  12. S

    Calculating Mie Scattering of Salt Particles

    Hello, can anyone tell me the equation to the Mie scattering. I have salt particles of a specific size, and I want to work out the Mie scattering of it. Thanks a lot From steve.
  13. C

    Scattering and wavelength dependence

    i don't know why the longer the wavelenght, the easier for it to be sattered ?
  14. J

    LED light diffraction, scattering

    I am constructing a 'white line detector' to use on the underside of a robot. The crucial components are an ultrabright red LED and a light-to-voltage converter. My initial idea is to leave the LED as it is, i.e. unshielded. I have to light-to-voltage converter, which is a phototransistor...
  15. J

    Dielectrics scattering electromagnetic waves

    Hello everyone, First and foremost I would like to see if everyone's having a good day? (assuming you respond yes) Awsome! Secondly I was hoping someone would be able to help me understand how dielectrics work. I don't need to know everything about dielectrics. I only need to know how...
  16. O

    Strong force, low energy proton scattering

    Homework Statement A beam of low energy protons is observed to scatter elastically from a target of neutrons. Sketch the variation of the differential cross section with the resulting scattering angle and comment on a characteristic feature of the strong force than can be deduced...
  17. E

    Solving Scattering Problem: Find Diff Cross-Sec in Limit of a→∞

    Homework Statement A particle with mass m scatters off of the potential V=A\delta(z) for -a \leq x \leq a and -a \leq y \leq a V= 0 otherwise Find the differential scattering cross-section using the Born approximation and show that in the limit where a goes to infinity the resulting...
  18. E

    Classical scattering off a paraboloid

    Homework Statement Particles are scattered (classically) from a paraboloid shape. The surface is given by the relation: z = a \left(\frac{y^2+x^2}{R^2}-1 \right) for x^2 +y^2 leq R^2 where a and R are constants. The particle is incident from z = -infinity with impact parameter s. Show that...
  19. E

    Classical scattering off an ellipsoid

    Homework Statement Particles of scattered off the surface of an ellipsoid given by x^+y^2+z^2/f^2 = R^2, where f and R are constants. Find the differential cross-section.Homework Equations The Attempt at a Solution Let s be the impact parameter. I can find s as a function of the scattering...
  20. A

    Doubt about Bhabha scattering.

    I have one doubt about Bhabha scattering which is scattering between one electron and one positron, two oppositely charged particles. Why should they scatter each other away rather than attract and eventually annihilate themselves, giving rise to the pair annihilation process? (This process is...
  21. 2

    Coherent scattering in BCS semicon?

    Hello experts, I've had some fun reading the posts in the various forums, and now it's time for me to ask a question. Is it possible to scatter light off of a BCS semiconductor such that the light can be considered to scatter from the coherent state of many Cooper pairs, rather than just...
  22. J

    Updating Carrier Momentum after Scattering

    Homework Statement Updating the carrier momentum after scattering is most easily accomplished in the rotated coordinate system. The rotated x-axis is related to the original x-axis by x_{r} = Y_{\theta}Z_{\varphi}x where Y_{\theta} describes a rotation of {\theta} about the y-axis, and...
  23. E

    Solving Griffiths' Scattering Problem in Introduction to Elementary Particles

    Hi , I got stuck on a point of griffiths' scattering problem on "the introduction to elementary particles" Homework Statement Consider the case of elastic scattering , A+B-->A+B , in the lab frame (B initially at rest) assuming the target is so heavy (mbc2 >> Ea) that its recoil is negligible...
  24. Q

    Simulating Two-Level Electron Scattering

    Homework Statement I have to simulate a two-level electron scattering process. 1000 electrons start in state i and over time, end up in state f. I need to plot the number of electrons in each state as a function of time. Homework Equations None. The Attempt at a Solution The probability...
  25. N

    Compton Scattering from bound electrons

    Can anyone please refer to a link where Compton Scattering is treated considering the electron to be bound in the atom?
  26. C

    Understanding Thomson Scattering for Non-Experts

    Can anybody provide me with information on thomson scattering for someone who hasn't done electrodynamics? I find ones like http://farside.ph.utexas.edu/teaching/jk1/lectures/node85.html but I don't know anything about solid angles and the scattering cross section is confusing me. I'm...
  27. P

    Nuclear Interactions: Inelastic and elastic scattering

    I originally posted this in the homework section until I realized the homework section only covers through undergraduate courses. The course I am currently in is a graduate level Medical Physics course. So if you don't mind, here is the thread I posted in the homework section. I am...
  28. P

    Nuclear Physics Scattering: Elastic, Inelastic etc

    I am preparing for a Nuclear Physics test. One of the homework problems asks the following: Choose the proper neutron interaction type for each of the following scenarios and explain why. Interaction types: elastic, inelastic, (n, \gamma),(n,2n),(n, \alpha). A. 10-MeV neutrons...
  29. N

    Compton Scattering MCQ: Min No. of Collisions to Absorb Photon

    Homework Statement A photon of wavelength \lambda enters an electron gas.What is the minimum number of collisions that could result in the photon being completely absorbed in the gas? (a) \approx\lambda\frac{mc}{2h} (b) \approx\lambda\frac{mc}{h} (c) \approx\lambda\frac{2mc}{h}...
  30. S

    Calculating Scattering Cross Sections

    Homework Statement A beam of \alpha-particles, of kinetic energy 5.3 MeV and intensity 10^{4} particle/sec, is incident normally on gold foil with thinckness 1 x 10^{-5} cm. (The density, atomic weight and atomic number of gold are 19.3 g/cm, 197 and 79 respectively.) A particle counter of...
  31. S

    Rutherford scattering calculation

    Homework Statement The fraction of 6.0 MeV protons scattered by thin gold foil, of density \rho=19.3 g/cm^{3}, from the incident beam into a region where scattering angles exceed 60 degrees is equal to 2.0 x 10^{-5} . Calculate the thickness of the gold foil using the result of the previous...
  32. M

    Proton Scattering: Calculating Current Density

    Homework Statement 50uA beam of 1MeV proton Target = Iron of 0.05um thick Calculate scattered current density at distance 5 cm at 20 degrees angle Homework Equations \sigma(E,\theta) = \pi*Z_{1}Z_{2}e^{4}(M_{1}/M_{2})/ET^{2}The Attempt at a Solution I figured the probability of scattering to...
  33. K

    Understanding Mie Scattering: Exploring Angle Dependent Formulae and Functions

    Hello, I do a research concerning Mie scattering. The Mie formulae are angle dependent, but I need a function from which I'll get the scatterd angle (as a function of some dependent parameter), can someone please direct me in the right way ?
  34. Z

    What Is the Incident Photon Wavelength in Maximum Energy Compton Scattering?

    Homework Statement If the maximum energy transferred to an electron during Compton Scattering is 50KeV, what is the wavelength of the incident photon? Homework Equations \lambda' - \lambda_{o} = h/(Me*c)(1-cos\theta) The Attempt at a Solution We know that the maximum energy...
  35. H

    Does Dust Scattering Alter the Cosmic Background Radiation Spectrum at z < 100?

    I was reading section 24 of Peebles "Principles of Physical Cosmology" where he analizes the impact of scattering by dust at redshifts z < 100 on the cosmic background radiation for an Einstein-deSitter universe. I was disappointed to find out that at the end of the subsection he concludes that...
  36. U

    Rutherford scattering and nuclear physics

    hi, i am a new student here in this forums from uae and i am studing in uaeu my majore is general physics >>> in this corse i have problem in nuclier physics in rutherford scattering >>> can you help ma pleaseeeee the problem are : firest one is : Show that the distance of...
  37. W

    Photon scattering with a moving electron

    Hello, The problem I have is trying to derive a formula for the compton equation, but instead of having the electron at rest, it is moving in the same direction as the incident photon. I've tried deriving it in the same manner as deriving it for an electron at rest (ie. I've simply made the...
  38. I

    How are \Theta and \theta related using conservation laws?

    \alpha particle of mass m is scattered by a nucleus of mass M. \Theta is the scattering angle of the \alpha particle in the LAB reference frame, and \theta is the scattering angle in the CM frame. What is the relation between \Theta and \theta using conservation of energy and momentum? I am...
  39. E

    Compton Wavelength Change: Blue Light & X-Rays

    [b]1. Homework Statement [/b Robinett question One of my homework questions in the Compton scattering section asks: "Evaluate the fractional change in wavelength delta lambda/lamdba, for incident blue light and X-rays? It also gives the wavelength of blue light and X-rays. I do not know what...
  40. T

    Can the Drude Model Explain Scattering Time in Terms of Unit Conversion?

    I got the answer of the hw, but still have question about it. I need to calculate the scattering time μ = eτ / m. τ is the mean time. the unit needs to be in cm^2 / V.S I put the unit like this : e = coulumb τ = s m = kg then it's impossible to get the unit like that. Then I'm...
  41. P

    Compton scattering: electron absorbs then emits a photon?

    Hello, In Compton scattering, does the electron absorbs a photon and then emit another photon with another energy?? I couldn't understand how would the electron absorb a FRACTION of the photon's energy which is forbidden in QM. Regards
  42. P

    Feynmann diagrams, bhabha scattering

    There is nowone who can help me on the homework forum, so i'll try it here...
  43. N

    Rayleigh scattering in Earth's atmosphere

    Does anyone know a rough ballpark figure for the opacity of the Earth's atmosphere in the visible? Assuming an observer is at sea level looking to the horizon, I calculated the opacity due to Rayleigh scattering in the visible band, as shown in the attachment. I don't really require a high...
  44. G

    Scattering Matrix: Solve 1D Schrodinger Equation

    Homework Statement We are interested in the solution of the Schrodinger equation with positive energy E = h_^2k^2/2m for the potential V(x) = -v_0*delta(x). We take the scattering state under the form Ae^ikx+Be^-ikx for x<0, and Ce^ikx+De^-ikx for x>0 Find the scattering matrix S(k)Homework...
  45. Demystifier

    Decay and scattering: What happens between the final and the initial state?

    For processes of particle decay and inelastic scattering, quantum field theory (QFT) predicts well the probabilities of various final states for given initial states. Technically, this is described by the S-matrix, which is the unitary-evolution matrix describing the transitions from t=-infinity...
  46. T

    Rutherford alpha particle scattering

    Homework Statement A parallel beam of alpha particles with fixed kinetic energy is normally incident on a piece of gold foil. a) if 100 alpha particles per minute are detected at 20 degrees, how many will be counted at 40, 60, 80 and 100 degrees? b) If the kinetic energy of the incident...
  47. H

    Inverse Scattering Transform and Solitons

    Hi all. Any someone recommend an introductory text on Inverse Scattering Transform and about solitons? I am currently using "Solitons and Inverse Scattering Transform" by Segur nd Albowtiz, which I think is too advanced for me, an engineering student.
  48. L

    Sky colour explanation by scattering

    I have done a little research on the internet and I would like to ask my concept is correct or not. 1) Sky is blue As the effect of rayleigh scattering is more effective for shorter wavelength, blue light scatter more than others (e.g. red). Furthermore, our eyes are more sensitive to blue...
  49. M

    How Does Bragg's Law Determine the Angle of Gamma-Ray Deflection?

    1. Question A cubic crystal of interatomic spacing of 0.24 nm is used to select gamma–rays of energy 100 keV from a radioactive source containing a continuum of energies. If the incident beam is normal to the crystal, at what angle with respect to the incident beam do the 100 keV...
  50. P

    Newtonian Solution to Compton Scattering

    Homework Statement I need to derive the Compton scattering formula using Newtonian mechanics, I have it done in relativistic mechanics but can't get the Newtonian version. Homework Equations the solution to the relativistic equation is 1=mc^2(1/E2-1/E1)+cos(theta) for Newtonian...
Back
Top