Questions tagged [mean-free-path]
The average length that a molecule will travel in a fluid before colliding with another molecule.
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Derivation of relativistic mean free path
I am working through a short derivation found in Abramowicz 1991 regarding the mean free path of a photon.
We have a fluid moving in a particular direction with velocity $v$ and in an inertial rest ...
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Mean free path equation for plasma
Does the mean free path equation
$$\lambda=\frac{1}{\sqrt{2}\pi d^2 n_v}$$
work for collisions in plasma or just for gas?
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Predicting electrical mean free path in nanostructures?
How does one roughly predict the
mean free path for
electrical conduction
in a nanostructure at different temperatures and under different electrical conditions such as different voltages and ...
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Determining the single particle energies in a neutrino opacity calculation
I'm attempting to recreate some plots from this paper on neutrino opacity calculations for interacting matter at supra-nuclear densities. Namely, I'm trying to write a Python script to perform the ...
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Standard deviation for a free path distribution
I would like to be able to describe a particles path before collisions with greater precision. We can calculate the "mean" free path of a particle before colliding moving particles, but I ...
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How is number of collisions per unit distance related to mean free path?
Recently I have been studying Kinetic Theory Of Gases, with one of the topics as collision frequency. I know that collision frequency is inverse of relaxation time which is also the measure of number ...
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Why does computing mean free path from an air molecule's reference frame seem to greatly overestimate path length?
I was interested in seeing if I could derive the mean free path of an "air molecule" by considering the reference frame of an individual molecule as other particles moved around it randomly. ...
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How to calculate the free mean path of electrons in the gas mixture? [closed]
How to calculate the free mean path of electrons in the gas mixture? I understand (a little bit) the mean free path concept for the atomic collisions but I am not sure what to do if I am interested in ...
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Number of fog droplets in the air
I have an issue with the official solution to this problem from BelPhO:
Visibility on the road is 100 m. Assuming that the diameter of a fog
droplet is 1 micron, estimate the concentration of fog ...
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Do photons slow down this much in the Sun's gravitational field?
I just heard someone mention that photons take 40 thousand years to travel from the centre of the Sun to its
surface which is roughly 700,000 kilometres. How is that possible if the speed of light/...
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Why is the mean free path length of an electron in a solid described by a "universal curve"? (doesn't include electron density)
I've been experimenting with XPS (X-ray photoelectron spectroscopy) and learned that the depth from which the observed electrons originated depends on their mean free path length, which makes sense to ...
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Mean free path of molecules
So in the book concepts in thermal physics(by Stephan and Katherine Blundell) the expression of mean scattering time is derived as shown(please refer the book for more). If we replace vdt in the ...
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Mean free path of gas mixture
I come cross a question about calculate the MFP of a gas mixture, which contains several different kinds of molecules, each has different size, velocity and number density. My question is: How can I ...
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Why is the sphere of influence of the molecule in mean free path a cylinder?
In my book for deriving mean free path a cylinder is taken to act as a sphere of influence of molecules with which it could bump into other molecules and its radius = diameter of the molecule we are ...
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How does $\frac{\langle v\rangle}{\langle v_r\rangle}=\frac{1}{\sqrt2}$ imply the formula for the mean free path?
In this question, it was asked how the formula $$l=\frac{1}{\sqrt 2n\sigma }$$ can be rigorously derived for a Maxwell-Boltzmann gas.
Here $l$ is the mean free path length in a gas, $n$ is the gas ...
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