What is Attenuation: Definition and 133 Discussions

In physics, attenuation or, in some contexts, extinction is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable attenuation rates.
Hearing protectors help reduce acoustic flux from flowing into the ears. This phenomenon is called acoustic attenuation and is measured in decibels (dBs).
In electrical engineering and telecommunications, attenuation affects the propagation of waves and signals in electrical circuits, in optical fibers, and in air. Electrical attenuators and optical attenuators are commonly manufactured components in this field.

View More On Wikipedia.org
Recent contents Top users
  1. W

    Free Space Attenuation: Understanding Radio Wave Loss

    Hi All, I'm reading about the attenuation of radio waves in space and I understand that, in addition to the normal attenuation that is proportional to the inverse of the square of the distance, there is also a loss due to the medium. This surprised me as I thought that there was no loss...
  2. I

    Radioactive flux attenuation in air - Need Help

    Hi, If we calculate the flux at a certain distance from a source of radiation by first neglecting the effect of attenuation in air, how does one factor in the effect of air attenuation? I do not know how to apply that theory. I'm am trying to understand what the difference is at sea level...
  3. P

    Electromagnetic wave attenuation

    Hi, I am just curious; do EM waves attenuate in a vacuum? If yes, how does this happen? Also, how do they faint through a medium?
  4. S

    Why are wirewound resistors unsuitable for RF applications?

    Dear All I am hoping for some insight into a transmission line problem I have been experiencing. I am quite inexperienced and unqualified in this area so if I am not clear please let me know. In wiring loom assemblies my employer offers there is a twisted transmission pair. The...
  5. M

    Mass attenuation coefficient of silicone polymer

    I'm trying to work out how much energy from sunlight will be absorbed (converted to heat energy) by a silicone polymer. I need the mass attenuation coefficient (from what I can tell at least) so that I can work out the amount of heat energy the water inside a black silicone polymer container...
  6. J

    Atmospheric Opacity and laser Attenuation query

    I would appreciate assistance with a thought experiment I've been having trouble with. What I asked myself was, If I had two Lasers of equal Intensity/power, say 200 milliwatts, one appearing green and the other red, with wavelenghts of say 555 nanometres and the other 660 nm, which laser...
  7. M

    Finding the Right Filter for -140 dB 60 Hz Attenuation

    Does anyone know how to filter 60 hz down to -140 db all the notch filters I tried are about -60 db maximum but after I amplify the signal to 100db the 60 hz becomes a problem again. I need a filter for this it doesn't have to be one stage and also I need the 100hz, maximum attenuation on 100...
  8. K

    How Are Gamma Rays Absorbed in Materials Used Practically?

    I need to know the practical applications of the absorption of gamma rays in materials.
  9. A

    Complex Wave Vector in Partial Reflection at a Conductor Interface

    Homework Statement I'm writing a school paper on the behavior of electromagnetic waves when they hit the interface between a non-conductor and a conductor. My question is if, in the case of partial reflection, it is correct to allow for both components of the wave vector (the wave is...
  10. D

    Data Analysis: Gamma ray attenuation

    Hello, I'm attempting to analyse the data recovered from an experiment that I performed in lab, but I'm having some problems understanding how to properly apply the statistical methods learned to this specific problem. Essentially, the experiment consisted of placing a source of gamma rays...
  11. O

    Solving Attenuation Coursework Problem for Salters A2 Physics

    The Problem I'm doing Salters A2 Physics coursework. Have chosen to do attenuation of projector slides but need some help with project variation. I feel that just finding an attenuation coefficient for the material that the slides are made from will give me few measurments and therefore not...
  12. S

    Mass attenuation coeffcient relation to kinetic energy

    the mass attenuation coefficient is related to the maximum kinetic energy of the beta ray spectrum ( T max) by this equation mu subscribe m (symbol) = 1.7 / (1.14 T max) the problem here is that the denominator in my text is in the form of a matrix and as well all know a matrix doesn't give...
  13. I

    Exponential Attenuation and Beta Particle Range

    Exponential Attenuation and Beta Particle Range (solved) Homework Statement I am given a beta emitter and its atomic mass, as well as the atomic mass of its daughter, which have a difference of 0.0034 amu. I am to determine the range of the particles in air. Homework Equations I am given...
  14. M

    What is the significance of measuring attenuation in gamma rays?

    Hello everybody, actually yesterday i read about an experiment "ATTENUATION OF GAMMA RAYS". can anybody tell me what is meanning of word ATTENUATION.And why we are measuring it? i.e. what is the sigificance of measuring it?
  15. V

    Finding freq., Wavelentgh, Phase Velocity, and attenuation constant

    Homework Statement Given... v\left(z,\,t\right)\,=\,5\,e^{-\alpha\,z}\,sin\left(4\pi\,\times\,10^9\,t\,-\,20\pi\,z\right) where z is distance (m), find... (a) Frequency (b) Wavelength (c) Phase Velocity (d) At z = 2m, the amplitude is 1 [V], Find the attenuation constant (\alpha)...
  16. K

    Eddy currents are causing major delay and attenuation

    Hello everyone. I am trying to measure the position of a magnet moving inside a steel tube using a magnetic sensor on the outside. Eddy currents are causing errors due to phase shifts and amplitude changes. Any ideas? Can eddy currents be re-directed using selective copper paths? Since eddy...
  17. E

    Electric pulse attenuation

    Hallo to all, I have been reading a paper regarding electric pulse attenuation and the values are quoted in dB. The conversion to dB was done by multiplying the value with (20log10e) where "e" is the base of the natural logarithm. I see this conversion to dB fist time. I can not find any...
  18. S

    Prove Attenuation Length = Avg Photon Travel Distance

    Homework Statement Show that the attenuation length, \Lambda, is just equal to the average distance a photon travels before being scattered or absorbed. Homework Equations my book gives: number of photons absorbed = \sigma\rho I(x) dx number of photons present after a thickness x...
  19. F

    Sound Attenuation: Investigating & Questions Answered

    Sound attenuation for my physics project I decided to investigate sound attenuation effect, for my equipment I’m using a speaker with a signal generator and at the other end a microphone with an oscilloscope...the sound generator and receiver were placed inside a tube which was well...
  20. F

    Physics Project: Investigating Sound Attenuation

    Sound attenuation for my physics project I decided to investigate sound attenuation effect, for my equipment I’m using a speaker with a signal generator and at the other end a microphone with an oscilloscope...the sound generator and receiver were placed inside a tube which was well...
  21. S

    Muon Attenuation: Is Heavy Metal Significant?

    I am looking at muons being lost as they travel through a concrete bunker (with various things inside). The minimum energy (mean) for a muon to go through the walls is about 1.82GeV, and for the stuff inside (flakes of magnesium) it is 2.7GeV. For a piece of heavy metal it is 0.13GeV (it's...
  22. N

    Calculating Light Attenuation in Glass: A Homework Problem

    Homework Statement If a glass material has losses at 10^3 dB/km, what percentage of the original energy exists after moving 30m down the glass material. Homework Equations Intensity = Power / Area = (Energy / time ) / Area dB = 10 log (Output Intensity / Input Intensity )...
  23. T

    Optical Fiber attenuation coefficient

    Hi, I am curious to know what is a typical numerical value for the attenuation coefficient of common optical fibre. Please don't include anything strange in the units like dB since I am new to that. Thanks.
  24. B

    Exponential attenuation law - simple

    Homework Statement Does alpha and beta rays obey the “Exponential law of attenuation”? Explain. The Attempt at a Solution I'm ashamed to be even asking this, but hey I am anyway. I was thinking that they do follow the exponential law of attenuation. However, I can't say that I'd be able...
  25. B

    Attenuation constant (low-loss dielectrics)

    \alpha =\frac {\omega \epsilon \prime \prime} {2} \sqrt {\mu \epsilon \prime} My question is what exactly does the \epsilon \prime \prime term signify?? I see sections of my notes that say \epsilon \prime \prime << \epsilon , but what is it? I mean when I am trying to find the attenuation...
  26. M

    Calculating % of X-rays Penetrating Lead with Al Attenuation Coefficient

    Okay, the question I'm suppose to answer is: If the attenuation coefficent of Al is 1.73/cm for soft-xrays, what percentage of X-rays penetrate a piece of lead 3.00mm in thickness . . . What I seem to have is I = Io*e^(-ux) I believe u = 1.73/cm and x = 3.00mm. My 3...
  27. D

    Electromagnetic waves and attenuation

    Hi i am trying to understand how long a electromagnetic wave can travel... What is the attenuation that the electromagnetic wave face in the atmosphere... This question arised when i have read that marconni at the beginning of 20th century has sent electromagnetic waves from england to canadA...
  28. D

    What materials have the lowest attenuation for electromagnetic signals?

    Hi to all ... Reading yesterday about optical fibers i have noticed that the fibers have a small attenuation so they are suitable for long distances.. I was wondering where i can find a table that show materials and the atenuation they provide to electromagnetic signals... I am really peculiar...
  29. E

    Solving the Attenuation Problem with High-Pass 2nd Order

    I am going blank here... I have a high-pass 2nd order (butterworth) that has fc = 5500 kHz, fp = 7kHz and fs = 1kHz and asked for attenuation at fc and fp. I end up with more loss on passband than on stop band! I am actually not sure how to approach this. Any help is very very much...
  30. MC363A

    What Causes Data Signal Attenuation Over Different Cable Lengths?

    Can anyone give me a good general formula or expanation for the diference in attenuation in a data signal in a network over a 500 and a 5000 foot cable? Help would be much appreciated. Thanx!
  31. M

    Electron Attenuation in Matter

    Hi everybody, I was wondering if somebody could help me find a chart or a table with electron attenuation lenghts or cross-sections in matter. I've searched the Internet inside-out but even if I would find something, it would be articles that you have to pay for :cry:. Still it seems a normal...
  32. A

    Experimenting with Sound Attenuation - Rich's First Post

    Hi there, first post from me - hurrah! I'm currently conducting an experiment measuring sound attenuation. I've got a table for the varying distances that measurements have been taken at, and the corresponding peak voltage values taken from a CRO. I understand that I have to take the log...
  33. C

    Optimizing ROI for Photon Attenuation Experiment

    Hi, I'm using a software program called Maestro for an experiment on photon attenuation. We observed that different region of interets (ROI) gives different mass attenuation coefficients. Is there a way to determine the best ROI besides choosing it so that it's closest to the accepted coefficient?
Back
Top