Diffraction Definition and 1000 Threads

  1. B

    X-ray Powder Diffraction: Determine Structure of Crystal

    Hello! X-ray powder diffraction can be used to determine the structure of crystal. I am given the diffraction angles (theta) for a sample and I am supposed to see if it has fcc, bcc or diamond structure. I read that if one plots sqr(sin(theta)) against ( sqr(h) +sqr(k) +sqr(l) ) where h, k, l...
  2. K

    Single-slit diffraction and small angle approximation

    Homework Statement Light of wavelength 587.5 nm illuminates a single 0.75 mm wide slit. (a) At what distance from the slit should a screen be placed if the first minimum in the diffraction pattern is to be 0.85 mm from the central maximum? (b) Calculate the width of the central maximum...
  3. P

    How High Must Charged Particles Be for Radio Wave Interference?

    Homework Statement An aircraft causes a horizontal layer of charged particles to be formed in the atmosphere. Radio waves are relected without phase from this layer. Radio waves of frequency 8.00 x 10^2 kHz are received at a location 12 km from the transmitter. What is the minimum height of...
  4. T

    Diffraction pattern and Fourier Transform

    hello I wonder if the diffraction pattern after Laserlight going thru a grating pattern (say 10 slots) has anything to do with the Fourier transform of the grating pattern. I am not a physicist, but have some knowledge of Fourier math. I think the spatial frequencies of the grating pattern...
  5. A

    Observing Single Electron Diffraction

    Homework Statement A single electron with de Broglie wavelength \lambda passes through a slit of width d = 2\lambda. The electron can then strike a flourescent screen. What will be observed on the screen? a) A diffraction pattern b) A single flash has if the electron had moved in a straight...
  6. M

    Is the Graph of Lattice Spacing vs Inverse Square Root of Voltage Linear?

    Homework Statement I'm just making sure I have the correct parameters for a linear graph. The experiment used a diffraction tube to verify deBroglie's hypothesis. The goal is to find the correct lattice spacings in graphite for d(10) and d(11). This might be lacking in pertinent information...
  7. L

    Equivalence principle and gravitational neutron diffraction

    In Modern Quantum Mechanics, Sakurai say that at quantum level the gravity is no more geometrical because the schrodinger equation depend on the fraction \frac{m}{\hbar}. Can someone explain better this claim or link me some detailed paper on this argument?
  8. M

    What is the wavelength of the sound waves emitted by two speakers?

    Homework Statement Two loud speakers emit sound waves of the same wavelength.When a microphone is moved between them quiet places are observed 20cm apart.What is the wavelength of the sound waves? Homework Equations The Attempt at a Solution
  9. P

    Interference and diffraction of light

    Homework Statement green light of wavelength 5000 A is incident normally on a grating, and the 2nd order image is diffracted 32 degrees from the normal. how many lines/cm are marked on the grating A=10^-10 n= 2 degree= 32 d=? wavelength- 5000 A the answer to...
  10. Ahmed Abdullah

    Can Diffraction Occur with Significantly Narrower Apertures?

    We know that to observe diffraction the width of the apertures in the grating must be of the order of the wave-length used. Would we observe diffraction if the apertures are significantly narrower than the order of wavelength used? Or what would be the difference? I think we would not observe...
  11. S

    Diffraction Grating: Finding Wavelength with Given Angle and Slit Density

    Homework Statement Monochromatic light shines on the surface of a diffraction grating with 5.3x10^3 lines/cm. The first order maximum is observed at an angle of 17 (degrees). Find the wavelength. a) 420nm c) 530nm b) 520nm d) 550nm Homework...
  12. H

    X-ray Diffraction: Smallest Angle of Scattering

    Homework Statement A powdered sample of a simle cubic crystal with a lattice constat of 2.83 x 10^-10 m scatters X-rays of wavelength 1.54 x 10^-10 m. What is the smallest angle of scattering that will be observed from this sample? Homework Equations 2dsinθ = nλ The Attempt at a...
  13. G

    Light Diffraction: Is Wavelength Affected by Slit Width?

    For diffraction patterns, the simple relation for the angle corresponding to dark fringes is sinθd = mλ/a, in which a is the width of the slit and m = {all integers excluding 0}. From this, it appears that a slit only allows certain wavelengths (a slit width corresponding to a length equal to...
  14. matt_crouch

    X-Ray Diffraction: Photon-Atom Interaction & De Broglie's Eq.

    How do the photons actually interact with the atoms to make them diffract. is it related to de broglies equation some how? Also with High energy electron diffraction, are the electrons being diffracted because they are attracted and repelled electrostatically from the nucleus and orbiting...
  15. P

    Can a Red Laser Create Beautiful Diffraction Patterns with Limited Materials?

    Hi I was wondering whether anyone could suggest ways of making nice diffraction patterns using a red laser. I work at a charitable school in Kazakhstan so am limited in terms of materials. Any suggestions would be appreciated. Thanks
  16. L

    How Does Incident Angle Affect Two-Slit Interference Patterns?

    Homework Statement Consider a plane wave (of wavelength λ) incident on a wall at an angle Φ = 30. There are two slits in the wall separated by a distance d=10λ. Each slit has width a<<λ. Rays emerging from the slits propagate to a distant screen where an interference/diffraction pattern may be...
  17. N

    What Are the Angles for Different Orders of Diffraction?

    Homework Statement Monochromatic light from a helium-neon laser(lambda=632.8nm) is incident normally on a diffraction grating containing 6000lines/cm.Find angles at which the 1storder,2nd.. Homework Equations The Attempt at a Solution here goes my solutions, given lambda=632.8 X...
  18. T

    Microwave Emitting Star, and detector with diffraction

    Homework Statement A microwave detector is located 0.5m above the surface of a large lake far from the shore. As a star, emitting monochromatic microwave radiation of 21cm wavelength, rises slowly above the horizon, the detector indicates successive maxima and minima in the signal...
  19. S

    Slit diffraction with a beam of spatially distributed intensity

    Homework Statement I have the classic slit-diffraction experiment, where light is incident on two narrow slits on a screen and is diffracted to create a pattern of maxima and minima on the far surface. It is usually assumed that the light incident on the slits is uniform. In practice, the...
  20. N

    Diffraction and interference patterns

    In Young's double slit experiment, how come the interefernece pattern produced does not take into account single slit diffraction? Thanks
  21. K

    Fourier Analysis's relation to diffraction

    My advisor recently asked me a series of questions that made me realize I don't fully understand how the Fourier transform of, let's say series of vertical lines, produces a diffraction pattern like those seen in a TEM. To get a better understanding I re-read Hecht's short little chapter on...
  22. T

    Narrow slits causes a diffraction pattern

    In the famous two-split experiment in your freshman college class, you learn that shining a light at a wall with two narrow slits causes a diffraction pattern. Something that's always bothered me is in these ideal setups, we always assume the wall is a continuous barrier to the light. But the...
  23. D

    What energies are needed to observe interference maxima in a crystal?

    A certain crystal has a planar spacing of .25nm. What energies are necessary to observe up to three interference (diffraction) maxima for a)electrons and b)neutrons?
  24. J

    Electron Diffraction and Particle Diffraction

    I have been looking for a comprehensive definition of what Electron Diffraction and Particle Diffraction and all my reference books etc. have ones which are hard to get into my head. Can anyone explain it from the point of view of a student to another student? Many Thanks, James
  25. K

    Diffraction grating and red light

    Homework Statement White light is spread out into its spectral components by a diffraction grating. If the grating has 2469 lines/cm, at what angle does red light of wavelength 635 nm appear in first order? Answer in units of ◦. Homework Equations sin(theta) = m(\lambda /d) The...
  26. I

    Solve Diffraction Grating for Red & Blue Light [URGENT]

    Diffraction Grating? [URGENT] Homework Statement Consider two monochromatic sources of light, blue light of wavelength λb = 460 nm and red light of wavelength 670 nm. The red light is shun upon a diffraction grating of density, nr = 10,000 lines per cm. A diffraction grating with what line...
  27. M

    Gravitational lensing and diffraction patterns

    Does gravitational lensing cause diffraction patterns, such as those seen by single, double, etc slit diffraction? In other words, would x-rays from object X get bent "less" than say microwaves or infrared? Would this happen if the light was passing between binary stars only, or could it...
  28. C

    Optimizing Beam Size for Increased Diffraction Efficiency

    In order to increase the diffraction efficiency of the AOM, we need to reduce the beam size of the laser. According to the manual of my AOM, it needs to have the beam size of 220um to get more than 90% diffraction efficiency. So, I decided to do so by putting a lens in front of it and...
  29. 6

    How Is Sound Intensity Affected by Diffraction and Slit Width?

    Homework Statement Diffraction occurs for all types of waves, including sound waves. High-frequency sound from a distant source with wavelength 9.20 cm passes through a narrow slit 11.5 cm wide. A microphone is placed 35.0 cm directly in front of the center of the slit. The microphone is then...
  30. 6

    How far is the screen from the slit? Diffraction problem.

    Homework Statement The distance d from the center of the pattern to the location of the third diffraction minimum of the red laser is 4.05 centimeters. The wavelength of the red laser is 633 nanometers and the slit is 0.15 millimeters wide. How far is the screen from the slit? Homework...
  31. T

    Fraunhofer diffraction and Fourier transform

    a Fourier transform of an aperature results the pattern of the fraunhofer diffraction fringes at infinity of light passing that aperature. How can we understand that point physically? I tried much to think about it! but no use. Everyone, Please give your thought about this, so I can have...
  32. S

    Fringe spacing for a diffraction grading (wave optics)

    Homework Statement A 550 lines/mm diffraction grating is illuminated by light of wavelength 550nm. How many bright fringes are seen on a 3.1-m-wide screen located 2.1m behind the grating? Homework Equations \DeltaY = \lambda*L/d where Y is equal to the fringe spacing... lamda is...
  33. M

    How Do You Solve These Diffraction Problems?

    DIFFRACTION PROBLEMS -- please help tough problems, any help or either one is greatly appreciated (1) Consider the single-slit diffraction pattern in figure V.2, which gives the location of the central maximum, and the zeros of the diffraction. If Z=1m and lambda=6*10^-7m, using the data...
  34. M

    DIFFRACTION PROBLEM (physics lab)

    One of my prelab problems for physics 3: The Moon is about 4*10^8 m from the Earth and has a diameter of about 3.2*10^6 m. You want a radar antenna which just covers the Moon with the central spot of its diffraction pattern. If the radar wavelength is 10 cm, what is the diameter of the radar...
  35. Q

    Huygens principle and single slit diffraction

    How can empty space act as individual point sources as in sinle slit diffraction?
  36. F

    Solving Optics Diffraction Questions: Orders & Intensity Pattern

    I have two questions here, 1. The two slits of a double slit each have a width of 0.140 mm and a distance between centers of 0.840 mm, (a) What orders are missing? (b) What is the approximate intensity of orders m=1 to m=3, relative to the zeroth-order maximum? 2. Sketch the intensity...
  37. Q

    What Is the Correct Slit Width for X-Ray Diffraction with a 10A Wavelength?

    Problem: Diffraction of X rays has been observed when a beam strikes an extremely fine slit. What must be the width if the slit if X rays of wavelength 10A are to display a diffraction pattern with a central beam of angular width 0.1? I used Bragg's equation to obtain...
  38. M

    Wave particle dualtiy and neutron diffraction

    1. A neutron has a kinetic energy of 10MeV. What size object is necessary to observe neutron diffraction effects? Is there anything in nature of this size that could serve as a target to demonstrate the wave number of 10MeV neutrons? K= 10MeV or 1.602 x 10^-12J Mass of neutron = 1.675...
  39. M

    Find Sin θ and D in Diffraction Equation

    Homework Statement I have to find "sinθ" and "d" in the diffraction equation. Homework Equations The formula is n(lambda) = d(sinθ) I have the n, length, width, and hypotenuse. http://img81.imageshack.us/my.php?image=captureee1.jpg n=1, L=335 W=42.5 hyp=337.8 The Attempt at a Solution I...
  40. B

    Diffraction Minima: Should I Use p or p+0.5 in the Equation?

    Homework Statement I did a physics lab the other day that dealt with two slit diffraction. In my setup, I also saw two faint diffraction minima, and it is my understanding that there is also some single slit diffraction effects. I measured the position a diffraction minimum to be y= 8.775...
  41. B

    Diffraction grating wavelength problem

    Homework Statement Light passes through a 200 line/mm grating and is observed on a 1.0 m wide screen located 1.0 m behind the grating. Three bright fringes are seen on both sides of the central maximum. What are the minimum and maximum possible values of wavelength? Homework Equations...
  42. G

    Fraunhofer Diffraction Doubt

    The relation between the angles for which the minima occurs for a Fraunhofer diffraction(parallel rays, large separation between screen and slit) is derived by using the destructive interference criterion. Why isn't there any mention of the criterion for maxima? The results obtained from the...
  43. N

    Deriving the formula for double slit diffraction as in Young from Fraunhofer

    Homework Statement I apologize for the blurriness in my title, I couldn't find anything better to fit within the length limit. The problem I'm stuck with, paraphrased, is to derive the formula for the diffraction pattern of a double slit, as found in the Young experiment, from the Fraunhofer...
  44. M

    Identifying Sides of a Diffraction Grating

    Homework Statement I have a diffraction grating , how will i know which side is ruled & which is not ? Homework Equations The Attempt at a Solution
  45. T

    What Is the Correct Spacing for Diffraction Grating Lines?

    Homework Statement A diffraction grating produces a third-order maximum, at an angle of 22 degrees, for red light (694.3 nm). Determine the spacing of the lines. Homework Equations for maxima: sin θm = mλ/d where m is the order of the maxima, λ is the wavelength in nm, and d is...
  46. C

    Diffraction Grating: Laser Illumination & 643 nm Wavelength

    Homework Statement A laser is used to illuminate a diffraction grating that has spacing of 637 lines per mm. The grating sits 11.6 cm in front of a screen. Find the distance to the first and second maxima (y1 and y2) for the laser wavelength of 643 nm. Express your answers in mm. Homework...
  47. G

    Calculating Wavelength Using Diffraction Grating

    Ok, so I'm going to have a lab final on diffraction gratings tomorrow, and I want to make sure I have the right idea. Basically we need to find out the wavelength of an unknown light using a diffraction grating. So let's say the grating is perpendicular to the light, and the distance from the...
  48. G

    Single slit diffraction / wave propagation

    I have a couple of questions about single slit diffraction. It's not a homework exercise - just a conceptual problem. Here it is (with some introductory comments)... I understand that the diffraction pattern from a single slit is the modulus squared of the Fourier transform of the aperture...
  49. E

    Solve Diffraction Question: 2 Speakers 4.0m Apart, 325Hz, 343m/s, 4.5m Away

    Homework Statement I am having difficulty with this problem because I am not quite sure where to start. A lecturer is demonstrating two-slit interference with sound waves. Two speakers are used 4.0 meters apart. The sound frequency is 325 Hz and the speed of sound is 343 m/s. Students sit...
  50. K

    Diffraction Grating: What's It Called?

    "Diffraction Grating" We did a diffraction experiment involving single slits, double slits, and a diffraction grating. Apparently the diffraction grating that we got was "different" (according to a classmate). The diffraction grating was "criss-crossed" and didn't produce any dark fringes on...
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