Scattering Definition and 919 Threads

Homework Statement in rutherford scattering formula, N is proportional to (sin T/2)-4 where T is the scattering angle, N is the count rate per min. i have to find the relationship between N and T so how do i get a straight line graph out of this relationship? if i plot lg N vs lg T...

why is it that in rutherford scattering experiment, if i change my slit width from 5mm to 1mm with everything else the same, i get a 10 times difference in the count rate for the same angle say 30degrees? for example, 1 count takes about 100seconds for the 1mm slit width but 1 count takes...

I've been reading a bit recently on Second Harmonic Generation and came across a supposedly separate technique called Hyper-Rayleigh Scattering (HRS). Can anyone explain the difference? I came across this paper, but didn't understand the difference...

Suppose I have a 2x2 Hamiltonian describing a conducting channel, as a black box. H_{Rashba}=\sigma_y k_x - \sigma_x k_y and also suppose I have an incident 2x1 wavefunction with up and down spin components, to this black box. What I am trying to do is to write a 2x2 reflection (or...

Homework Statement I have simplified the expression -i\int d^4xie[\phi'^*(\partial_{\mu}A^\mu + A^\mu\partial_\mu)]\phi to -i\int d^4xie[\phi'^*(\partial_\mu\phi) - (\partial_\mu\phi'^*)\phi]A^\mu under the conditions A^0 \rightarrow 0, t \rightarrow \pm \infty |A^i| \rightarrow 0, |x_i|...

Assuming that the whole universe is electric charge neutral, there are neutral atoms, unbound electrons (which play the role in the last scattering), photons and decoupled neutrinos. So it seems to me there is no particle to "balance" the negative charge carried by the electrons. Did I miss...

edit: the TeX is still being screwy, not putting the equations in the right places. stay tuned. editII: fixed, I think. Homework Statement I'm working on converting a BRDF to a PSD, S(fx,fy). Homework Equations In the book 'optical scatter: measurement and analysis', the BRDF is given as...

Hi, I have a problem involving helicity. Homework Statement In a scattering e^{+}+e^{-} \rightarrow \nu_{\mu}+\overline{\nu}_{\mu} I have to determine for which values of the helicity of initial particles the cross section is not 0. Homework Equations The Attempt at a Solution On a...

Homework Statement In a relativistic collision between a photon and an electron, the recoiling electron has an energy of 40keV and the scattered photon an energy of 120keV. Find the energy of the photon before the collision, find the angles at which the photon and the electrons are scattered...

Hello everyone I've a question about the "time of the last scattering". My understanding is that this took place about 380,000 years after the big bang, and occurred when the universe cooled sufficiently to allow protons and electrons to form neutral hydrogens atoms. As a result, light was...

Homework Statement Hey. I've just conducted Rutherford's gold foil scattering experiment and am a little stuck on a part of the analysis. One of the objectives of the lab script is; 'To correct the counting rates measured in one plane for the fact that the foil scatters in a 3D cone'...

Homework Statement Suppose that an X ray has initial energy Eγ=100keV, and the incident (relativistic) electron has energy Ee=100GeV. Compute the final energy of the photon E'γ assuming the final direction of the photon makes an angle θ=Π with the initial direction. For solving this problem...

So when you calculate the scattered electron energy and the scattered photon energy (for 180 degree deflection) you get roughly the following (in keV). Photon(in)__Photon(scattered)__Electron(recoil) 27.5_______24.8______________2.7 81_________62_______________19...

Hi, I'm not sure how to do B1 part c, can anyone help? http://qm-web.library.qmul.ac.uk/exams/science/physics/2010/PHY-215.pdf

Hi all, I am trying to calculate the penetration depth of a beam of electrons which have an energy of 12 keV. The target material is aluminium (for x-ray production). Initially I tried doing calculations using a Beer's law type equation; however I got higher values then expected...

Homework Statement Could violet light ejecto photons from a metal by compton scattering? Homework Equations no The Attempt at a Solution If a photon of violet light is backscattered 180, the electron gain most energy(6.03*10^(-24)J). While the work function is aby a few eVs, but...

does anybody know a book, where the compton-scattering with respect to the initial photon-polarisation is calculated? (beside landau-lifschitz-berestetzki)

Hi there, I have little question: reading zee 2nd edition, I.8 (pag 64) i came up with this: start with <k_1 k_2| e^{-iHT}| k_3 k_4> and H=H_0 +u u=\lambda \int \phi^4 where H_0 is the usual hamiltonian for the free scalar field. Then, zee says that "expanding in \lambda, we obtain...

Homework Statement Ok, I'm given a formula for the cross section of the scattering and I've been told that the detector is a column of water of depth 10m. I need to find the probability of the scattering within the detector. Homework Equations σ = E(in MeV) x 1.5x10-44 cm2 The...

Hi, I had an issue with compton scattering that I never received a satisfactory answer for. My issue was that after the collision, there exists a y component of momentum... but all diagrams of the compton effect align the axis center to center from the photon to the electron and on top of...

Homework Statement Calculate the rate alpha particles reaches a detector in a ruthford scattering given the following data: Kinetic energy of particles: 10Mev rate of hitting the target: 10^6 particles/second target is thin lead foil 1mm thick and has the density of 11.3 g/second the detector...

Is there any user on this forum who have used the SAXSess? please reply to this post. I need some discussion.

Homework Statement A thin polycrystalline film of Cu, with lattice parameter of 0.361 nm, is irradiated with X-rays with wavelength of 0.154 nm. Calculate the first 5 bragg scattering angles for which X-rays may be detected.Homework Equations 2dsin(\theta) = n\lambda Bragg condition for...

Hi How is it possible for a homogeneous molecule (i.e. one not having a permanent dipole moment and hence not IR active) to be Raman active? What my confusion is that since we cannot excite any states in the molecule (since it is IR inactive), then how can any scattering process even occur...

What Does "Quantum Gravity Scattering Amplitudes" Mean? I've seen it referenced in a few papers but I can't seem to find a definition. I know what "scattering amplitudes" means but don't understand the relationship with quantum gravity. What precisely is doing the scattering in quantum gravity?

Homework Statement Assuming that in electron scattering off a target proton you need to resolve a distance scale below R = 10^-15 m (that is, the uncertainty in the proton’s position is no larger than about 10^-15 m), determine a condition on the electron momentum, and justify it in one or...

I know that the sky appears blue because the blue light gets scattered the most due to its high frequency(according to Raleigh's law) but then during the sunset or sunrise, why does the sky appear red? Doesn't almost all of the blue light get scattered , and maybe just a small portion of red...

I don't quite understand why we see sunsets as red/orange/yellow. We see the sky as blue because Rayleigh scattering causes the smaller particles within the atmosphere to scatter bluer wavelengths and absorb others. But if the others are absorbed, which would include the red/orange/yellow...

hi how to calculate the traces of product of Dirac matrices in QED. i want caculate crossection of process scattering in QED. a program to calculate it

I am researching smart structures using optical fibre based sensors. One type used is distributed sensors of which there are two main kinds: ROTDR (Raman Optical time domain reflectometer) and BOTDR (Brillouin Optical time domain reflectometer). The former is based on Raman scattering within the...

Homework Statement Obtain the analytic expression for the N-channel T-matrix assuming a separable potential. Hint: assume that T is proportional to V. Specialise your answer to N=1 and perform the required integral to get an explicit form for T, assume the given form for g(k)...

I've been trying to get some insight into the light scattering mechanism that occurs in colloidal solutions via the Tyndall effect and was hoping some of the resident experts here could shed some light... on this. Tyndall scattering occurs with particles that are roughly the size of the...

i am reading about Rayleigh scattering in light and have come to understand that atoms absorb light of particular frequencies and then scatter it in different directions. But why do they scatter the light on the first place? Also, why do smaller atoms scatter higher frequency light?

I have some questions here regarding phase shift and scattering. 1). I am working out an exercise for my own benefit, for which I already have the solution, but there are parts of it I don't understand. I am given a scattering delta potential: b*delta(r - a), where b is a constant, and I am...

What is Nima talking about at 42 minutes? http://www.cornell.edu/video/?videoID=913&startSecs=0

Homework Statement A photon of energy E is scattered off a stationary electron with rest mass m. What is the maximum kinetic energy of the recoiling electron?Homework Equations \lambda'-\lambda=\frac{h}{mc}(1-cos(\phi)) E=\frac{hc}{\lambda}The Attempt at a Solution The maximum kinetic energy...

Can anyone explain why there is an inverse relationship between target to detector distance and scattering angle? Thanks.

Homework Statement Compton's derivation of his scattering formula: \delta \lambda \equiv \lambda' - \lambda = \frac{hc}{m_e c^2} (1 - cos\theta) assumed that that the target electrons were at rest. In reality, they are orbiting around nuclei. In a material like lead, the electrons have a...

Homework Statement Suppose a 0.511[MeV] photon from a positron-electron annihilation scatters at 110 degrees from a free electron. What are the energies of the scattered photon and the recoiling electron? Relative to the initial direction of the 0.511[MeV] photon, what is the direction of the...

hello there! your help is really appreciated. 1.For the Ruther alpha-particle scattering experiment, how come we are only concerned with the nucleus of the gold with repulsion on the alpha particle? what about the electrons in gold? Don't they attract the alpha particle? 2. To calculate...

I've been reading some of my old physics books and I'm currently reading about Compton scattering. It got me to thinking - is there is a minimum Compton scattering angle? Is there a point where it becomes highly unlikely (or impossible) for a photon to be Compton scattered?

Homework Statement Verify the following equation \frac{E^{1}}{E}=(\frac{A-1}{A+1})^{2} Where A is the atomic mass of the target nucleus hit by an incoming neutron, E is the energy of the neutron before collision, and E^{1} is the energy of the neutron after collision. Please note that the...

Hi, I have a question about the divergence of forward Coulomb (Bhabha/Moller) scattering. I guess the classical analog of it is the Rutherford cross-section divergence, but that can be explained by the infinite impact parameter. In the QED version - the Bhabha/Moller scattering, it is...

Hi, I have a question about the divergence of forward Bhabha/Moller scattering. I guess the classical analog of it is the Rutherford cross-section divergence, but that can be explained by the infinite impact parameter. In the QED version - the Bhabha/Moller scattering, it is the matrix...

URGENT - Compton Scattering - Electron Momentum Homework Statement An x-ray photon of initial energy 1x10^5 eV traveling in the +x direction is incident on a free electron at rest. The photon is scattered at right angles into the +y direction. Find the components of momentum of the...

For reference: http://arxiv.org/abs/astro-ph/9912312" The paper linked above notes in the introduction: The authors are performing this calculation for an isotropic electron distribution. However, for my work, I am considering an electron population with a relativistic macroscopic bulk...

I am following advice from this page: http://www.phys.uu.nl/~thooft/theorist.html and I'm particularly puzzled by the following topics (in bold): Maxwell's laws in a medium. Boundaries. Solving the equations in: * vacumm and homogeneous medium (electromagnetic waves) * in a...

Can someone qualitatively explain the difference between Raman scattering, Rayleigh scattering, and Brillouin Scattering with respect to molecules? I attempt to define each below but would appreciate either affirmation I'm correct or correction if I'm wrong. Raman scattering - Molecules...

Hey folks, another question. What is the difference between hard and semi-hard scattering events? In terms of energy I found for both s >> t, so where does the difference lie? Thanks, Earth's

Hey folks, as said in the title: What is the meaning of "inclusive scattering" and "exclusive scattering"? Thanks, earth2