What is Absorption coefficient: Definition and 22 Discussions
For "attenuation coefficient" as it applies to electromagnetic theory and telecommunications see Attenuation constant. For the "mass attenuation coefficient", see Mass attenuation coefficient.The linear attenuation coefficient, attenuation coefficient, or narrow-beam attenuation coefficient characterizes how easily a volume of material can be penetrated by a beam of light, sound, particles, or other energy or matter. A large attenuation coefficient means that the beam is quickly "attenuated" (weakened) as it passes through the medium, and a small attenuation coefficient means that the medium is relatively transparent to the beam. The SI unit of attenuation coefficient is the reciprocal metre (m−1). Extinction coefficient is an old term for this quantity but is still used in meteorology and climatology. Most commonly, the quantity measures the value of downward e-folding distance of the original intensity as the energy of the intensity passes through a unit (e.g. one meter) thickness of material, so that an attenuation coefficient of 1 m−1 means that after passing through 1 metre, the radiation will be reduced by a factor of e, and for material with a coefficient of 2 m−1, it will be reduced twice by e, or e2. Other measures may use a different factor than e, such as the decadic attenuation coefficient below. The broad-beam attenuation coefficient counts forward-scattered radiation as transmitted rather than attenuated, and is more applicable to radiation shielding.
##\alpha## is considered to be the absorption coefficient for a beam of light of maximum intensity ##I_0##. It's related to the complex part of the refractive index as we have shown above. Now, I have a doubt. Should I solve for ##k## from the quadratic equation in terms of the linear optical...
Why is the absorption coefficient (##\alpha##) of water is always given using the units ##\text{length}^{-1}##, while for other materials it is often given by ##\text{length}^{2}.\text{mass}^{-1}##?
For instance, this paper uses ##cm^{-1}## for water and yet ##cm^2 / \mu g## for other...
Homework Statement
I am conducting an experiment where I am interested in finding the absorption coefficient of different materials as muons pass through them. My data was all well until I realized more muons were measured AFTER they passed through one of the materials, which makes no sense...
Hi. I'm trying to model the attenuation (extinction) of a weak laser through a gas sample using the Beer-Lambert law. I've found that the attenuation cross section can be written as the sum of both a scattering and absorption cross section, however I'm having difficulty finding a source that...
hi every one
can you tell me how to calculate the absorption coefficient of a thin film using the absorption and the transmittance spectrum plotted as a function of the wavelength (knowing that i don't know the thickness of the film )
Anyone can explain me this example?
I substitute value for
e = 1.602*10-19;
m0 = 9.1*10-31;
pi = 3.14;
and calculated value for μav in matlab.
I received 1.7104*10-19. But in exam this value is 0.68*10-25.
What is i wrong?
please help me.
Thank you.
Hi All,
I am designing an optical solid phantom to represent tissue optical properties (scattering and absorption coefficients).
I know what should be the optical properties of tissue but I don't how much absorbing agent should I add to the mixture so that the phantom exhibit my desired...
The fact that energy in a laser can propagate without much loss over long distances is quite shocking !
It's a renowned fact that energy is dissipated when propagation takes place through any medium...
(I'm fully aware that laser is an exception)
But I have quite a difficult time understanding...
Hi,
I have some modelling code that uses data from Hitran 2012 (https://www.cfa.harvard.edu/hitran/Download/HITRAN2012.pdf). I want to use some data from Lifbase but unfortunately the absorption coefficient units do not match.
Lifbase units are given in m3 J-1 s-2 whereas Hitran units are...
I saw this on Wikipedia
http://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water
Isnt it supposed to less than 1 ?
maybe it has something to do with the unit ..why is it in m^-1?
I am looking for an exact value of absorption coefficient of aluminium for microwaves, but I can not find it in the internet. Anyone knows where I can find it?
I am currently trying to graph the absorption coefficient of Copper tetra-tert butyl phthlocyanine. I have the extinction coefficient vs wavelength graph and refraction vs wavelength graph however I don't know how to use these to graph absorption coefficient.
E(eV)=1242.4/λ
absorption...
we know that the quantum well absorption coefficient is calculated by summing over the electron-heavy hole and electron-light hole transitions:
α_{w}(E) = \sum_{n}α_{e_{n}-hh_{n}}(E) + \sum_{n}α_{e_{n}-lh_{n}}(E)
where n is the n^{th} transistion.
but when the photon flux is incident...
Hi everyone
Homework Statement
I'm looking for the molar absorption coefficient of Catechol but I can't find it anywhere. Can anyone help me out? I searched the internet as well as some books we have in our library, but I wasn't able to find it. Thanks for you help.
I was conducting an experiment, and we had to use a radioactive source and a Geigor counter, in conjunction with aluminium plates.
Using the data we produced we had to graph an absorption curve and obtain a value for the mass absorption coefficient of aluminium.
Then we had to compare this...
Hello all,
I come from musical sciences, but I'm trying to learn something about acoustics, so here I am, asking for some help about the impedance tube sound absorption coefficient test.
I have and impedance tube, two microphones technique (ISO 10534-2), B&K microphones connected to the...
Hello,
I am currently creating a program that calculates the change in observed intensity (nadir) from initial intensity within the atmosphere.
As I am studying particular compounds, a first suggestion for my work is to produce a 'forward model' based on very simplistic radiative transfer...
How is the absorption coefficient per unit path length determined for excitation sites in a host crystal with an excitation site density of N and a bandgap of the excitation site equal to the photon energy? What I am trying to determine is how many photons will be absorbed for a given length.
Homework Statement
Why is the mass absorption coefficient used rather than the linear absorption coefficient?
Homework Equations
mac=lac/density
The Attempt at a Solution
is it because mac is independent of physical from?
want to calculate absorption coefficient or absorption crosssection for 1% C2H2 gas
Path length = 1meter
Absorbene = 0.32
concentration = 8500ppm
pressure = 1 atm
Temperature = 25C
I need to express this concentration to mol/cm3.
Pls let me know if u have anyidea
Hi,
is there a way to calculate the two-photon absorption coefficient of silicon?
I am especially interested in the two-photon absorption coefficient of silicon for the wavelengths 1030nm, 515nm and 343nm.
Thanks for any help!
Hi. I am new here! I'm doing a experiment on the absorption of beta radiation of aluminium and I need help! :redface: Does anyone know what the absorption coefficient of aluminium? Or at least where I can find it. Thanks in advance! o:)
P.S. Sorry if I've posted in the wrong part of the forum...