Scattering Definition and 919 Threads

It is well known that back-scattering of surface electrons in topological insulators is prohibited due to Kramer's degeneracy theorem as long as Time Reversal Symmetry is not broken by magnetic field or magnetic impurities. I would like to know what effect this has on scattering length and...

Homework Statement Infrared telescopes, which use special infrared detectors, are able to peer farther into star-forming regions of the galaxy because infrared light is not scattered as strongly as is visible light by the tenuous clouds of hydrogen gas from which new stars are created...

Our condition for scattering is based on the idea that the amplitude of the outcoming wave is maximal, when all atoms contribute to a constructive interference. By using the attached drawing a simple relationship between the phase change of the two beams are derived. But my, maybe stupid...

Bee Hossenfelder has proposed a new approach to QG phenomenology, involving new ways to look for signs that space-time arises from a fundamentally non-geometric theory. The basic hypothesis is that if what looks like a geometric continuum actually arose from myriad nongeometric entities then...

Hi, I am slightly confused regarding the termenology elastic and inelastic. My focus is on the interactions, Rayleigh, photoelectric, comptonscattering and pair production. I have read around the internet and have some question I did not fully got answered. 1) Is Elastic = Coherent and...

Hi All, Following on from the last dumb question I asked... Suppose you calculate the tree-level approximation to the elastic scattering of two charged fermions to find that the result varies as ##\sim 1/t##, where t is the Mandelstam variable describing the squared momentum transfer in...

Hi does anybody here know whether there already exists a theory that describe Mie scattering for spheres that have a constant dipole moment?

Hello All. I'm currently in a crash course on X-ray Diffraction and Scattering Theory, and I've reached a point where I have to learn about Bessel Functions, and how they can be used as solutions to integrals of certain functions which have no solution. Or at least, that's as much as I...

Homework Statement In a Compton scattering experiment, a photon is scattered through an angle of 90.0deg, and the electron is scattered through an angle of 21.4deg. Determine the wavelength of the scattered photon Homework Equations Conservation of momentum and energy. p = h/lambda, E =...

Hello. I'm reviewing background information on Raman scattering and I've noticed that the polarizability scales with v+1 for Stokes transitions and v for anti-Stokes. Why is this and what assumptions are used in the derivation? An explanation or pointing me to a good reference would be...

I've been reading Coleman's notes and the book on QFT by Ticciati. There they both place a lot of emphasis on computing the scattering matrix S. I can follow their computations (using Wick's theorem etc.) but I don't really have a good understanding of what S actually tells you. Ticciati even...

Homework Statement Incomming photon gives half of its energy to an electron during scatering. After scattering, photon is headed ##\phi=120^\circ## according to the original direction. What is the ##\lambda## of the incomming photon? Homework Equations \begin{align} \Delta \lambda &=...

Homework Statement The length of the photon waves which are under Compton scattering ( compton scattering is applied on them) is measured in the angle =90 degree.If ΔΛ/Λ is 1.5 %,what is the length of the waves of the falling photons? Homework Equations The Attempt at a Solution...

Hi there, I am trying to calculate diffraction efficiencies of a lattice with the coupled wave theory. As material parameters the programm I got needs the atomic scattering factor f1 and f2. (see http://henke.lbl.gov/optical_constants/asf.html for elements) I understood this seems to...

Hi there, I'm learning about solitons and chanced upon this pdf talking about the inverse scattering method. However, I'm stuck trying to derive the coefficients using the LAX method (pg 5 of the attached pdf or from http://arxiv.org/pdf/0905.4746.pdf). Hope that someone can help shed some light...

Hi All, So the photoelectric effect is the phenomenon where an orbital electron fully absorbs an incoming photon (assuming the energy of the photon is greater than the binding energy of the electron) and is ejected from its shell. The electron can then undergo its own interactions in the...

Provide one of the following answers: PE,CS, BOTH, OR NEITHER. PE if the statement applies only to Photoelectric Effect. CS if the statement applies only to Compton Scattering BOTH if the statement applies only to both the Photoelectric Effect and Compton Scattering. NEITHER if the...

Hello. I am currently studying scattering theory in detail for my BSc thesis, and I'm starting with Rayleigh scattering. I'm following Scattering of electromagnetic waves: theories and applications by L Tsang, J A Kong and K-H Ding, which is pretty much what I like in a science textbook...

I have been watching Susskind's lectures on Cosmology which are great. There is something that I can't wrap my head around. I know that if we look far away enough into the past (about 100,000 years after the big bang I think he said) , the radiation that is being emitted comes from plasma and...

first question, would there be more rayleigh scattering on neon gas vs air? im wondering if you have a tube of neon gas, and shine a laser through it, will the laser beam become visible? as opposed to shining a laser pointer around and only seeing the dot.

Homework Statement Asked to calculate the relativistic correction, to the differential scattering cross section which is given by the equation below in terms of E, E0 and θ where E0= .511 MeV. with 100MeV electrons from an Au nuclei at certain angles θ. Homework Equations Relativistic...

Hello! Reading up on simulations of electromagnetic scattering with DG-FEM and trying some myself, I got stuck. In some of papers I have read, a scattering field formulation is used, in which the total field is linearly decomposed in incident field and scattering field...

Has anyone read or seen any articles that might highlight the techniques of Stimulated Raman Scattering Spectroscopy? Or just any knowledge on the process they would be able to share? I am having a tough time getting a hold on the process and if anyone has any useful information or articles that...

I've got a question that asks what the maximum scattering angle in \nu_\mu e \rightarrow \nu_\mu e is. The electron is stationary in the lab frame and after the collision has E >> m_e. The answer given is \sqrt{\frac{2 m_e}{E_e}}, independent of the neutrino's energy. How can I get...

Homework Statement What relations can you derive from isospin conservation for the cross sections of the following scattering processes: K^{+} + p → K^{+} + p K^{+} + n → K^{0} + p K^{0} + n → K^{0} + n The Attempt at a Solution I do not really have my own solution as I've...

Homework Statement Show that, for low energy photons scattered by ultrarelativistic electrons, the cange in frequency of the photon is given by (v'-v) / v = [(Ω'-Ω).β] / [1-Ω'.β] Homework Equations The full/general form of Compton scattering is given by v'/v = (1-Ω.β) /...

Homework Statement Consider the spherical well such that V(r<a) = -V0 and V(r≥a) = 0. Calculate the l = 0 partial wave scattering cross section in the low energy limit for this potential. Homework Equations σ = \frac{4 \pi}{k^2} * \Sigma (2l+1)*sin^2(\delta_l) The Attempt at a...

Hi Guys, I am doing a bit of work with dynamic light scattering (DLS) data. It is one of the many areas of science where we encounter an inverse problem. The forward problem is: For a known sized particle, calculate its scattered spectrum (that is easy). The inverse problem is: from the...

Homework Statement Use the boundary conditions to show that \frac{A+B}{A-B}=\frac{k_1}{k_2}\frac{C+D}{C-D}=\frac{k^2_1}{k^2_2} Homework Equations A+B=C+D and k_{1}A- k_{1}B = k_{2}C- k_{2}D C e^{i k_{2}L}+D e^{- ik_{2}L} = F e^{i k_{1}L} and k_{2}C e^{ ik_{2}L}- k_{2}D e^{-i...

Homework Statement In the non-relativistic limit, the equation for Compton scattering is v' / v = 1 / (1+x) where x = (hv/mc2)(1-Ω.Ω') Show that the change in frequency Δv = v' - v is given by Δv / v = -x Homework Equations The Attempt at a Solution I rearranged the...

Homework Statement A two-dimensional rectangular crystal has a unit cell with sides a 6.28Å and b 3.14Å. A beam of monochromatic neutrons of wavelength 5.0 Å is used to examine the crystal. Using either the Laue condition for diffraction or Bragg's Law, determine whether it would be...

Homework Statement Reading a textbook, I come across a situation where an electron is scattered off a nucleus. The book says p.P = p'.P', where p is the momentum of the electron and P is the momentum of the nucleus. I don't understand how it gets the conservation of scalar product. It's steps...

Well I am sure this is a lame question, but I am stuck over it for hours. I'm working on Bjorken, Drell book, and I'm trying to calculate the extreme relativistic differential cross section for electron-positron scattering. Well, I have evaluated the cross section up to my attachment's...

Homework Statement Given that the scattering amplitude off of a single atom is f_{1}(\vec{q}), find the scattering amplitude for 1) four atoms each placed in the corner of a square of length a, and 2) two atoms a distance d apart Homework Equations The total scattering amplitude can...

Hi all! I have been told that if an unpolarized photon hits an electron in a Thomson scattering the outcoming photon will be polarized because of the electron's spin. I didn't understand what it means, nor do I get how an electron reacts to an unpolarized photon: in Classical Electrodynamics...

I'm testing my faith in the photon. I understand that energy levels are quantized, and I understand that the EM field carries momentum. I want to make sure the idea of a photon is necessary to intuitively understand the observations. I am focused on compton scattering of a photon and an...

Hello PF people, Homework Statement In a Compton scattering event, after the collision, the Photon has an energy of 0.12 MeV and the Electron has an energy of 0.04 MeV. Find the following: i) The Wavelength of the photon before the collision. ii) The scattering angle for the photon...

I was reading Wikipedia article on Rayleigh scattering and came upon this: "...the major constituent of the atmosphere, nitrogen, has a Rayleigh cross section of 5.1×10^(−31) m^2 at a wavelength of 532 nm (green light). This means that at atmospheric pressure, about a fraction 10^(−5) of...

Consider a plane sound wave (\varphi^i) incident up on a solid object . The object will scatter this incident wave. Let this scattered wave pass through an interface separating two different fluids (say with sound speeds c1 and c2). Now at the interface, is the scattered velocity potential...

Homework Statement A photon carrying energy of 40keV scatters from an electron initially at rest. what is the maximum energy the electron can have? Homework Equations The Attempt at a Solution I tried using conservation of energy Initial: 40keV (energy of photon) + mc^2...

I'm looking at scattering theory and eventually the Born approximation... In the notes I am reading it says we want to solve the Schrodinger equation written in the form: ##\left(\nabla ^2+k^2\right)\psi =V \psi## Of which there are two solutions, the homogeneous solution which tends to...

Homework Statement Consider a blackbody contain atoms that typically produce photons with energy of about 7eV. Estimate the number of photon-electron collision each photon undergoes before it escape the object. Assume the blackbody has a temperature of 1000K. Homework Equations λ2 - λ1...

I apologize for not following the template, but it doesn't really fit. I would have posted it elsewhere but as it's for academic purposes I think it has to be here. Please excuse me if I'm wrong. I'm a high schooler working on a project, and I was planning to send ≈3 cm microwaves through an...

Homework Statement I need to give scattering amplitude f(θ) in Born approximation to the first order in the case of delta function scattering potential δ(r). The problem is in spherical coordinate and I'll give major equation concerned.Homework Equations The equation for scattering amplitude is...

I understand that in elastic scattering, the incident particle leaves the interaction with the same magnitude of momentum it had initially. But, can there also be a target particle recoil in this case? If the kinetic energy of the incident particle is conserved, how does the target particle...

Homework Statement Okay, so here's the problem: In a Compton scattering experiment, a photon is scattered through an angle of 90.0 and the electron is set into motion in a direction at an angle of 20.0 to the original direction of the photon. (a) Explain how this information is...

Hey all, Anyone know if there is a δt to Compton scattering or is it an instantaneous event, entertaining classical physics...billiard balls colliding in an elastic collision. Cheers

What is the difference between the two ? Maybe that in the photoelectric effect all of the energy of a photon is absorbed by the electrons ? Is that it ? In Compton scattering, only part of the energy is absorbed hence there is a photon of lower frequency emitted ! OR Maybe in the...

Homework Statement Determine the mass of the virtual photon in each of the lowest-order diagrams for Bhabha scattering (assume the electron and positron are at rest). What is its velocity? (Note that these answers would be impossible for real photons) Note: You can "just write down" the...

I am looking at a 1-d quantum system with a delta-potential barrier in the centre (at x = 0) and an infinitely high wall on one side of this barrier (at x = -a), while the system is open on the other side. So the potential V is equal to: V = κ\delta(x) at x = 0, κ being some constant and δ...