174 reputation
10
bio website
location
age
visits member for 2 years, 10 months
seen Jul 12 at 17:39

Jul
2
comment How are determined experimentally the energy levels of the atoms ? How is the calibration done to several decimal points?
Thank you. I get that a spectrometer could have high resolution. But I guess I am trying to understand how is absolute energy associated with particular absorption line ? Why is some edge at 284 not 280eV and why different people think some edges (absorption lines) are at slightly different energies ?
Apr
21
comment What is the reason that EXAFS are done with monochromatic x-ray light?
Thanks. My question is which process in the exafs fails if the beam is not monochromatic. Where is the TEY (total electron yield) used, is it in analysis. Arent photons that are collected?
Apr
21
comment Resolving power of a diffraction grating?
This is the condition for multiple N slit principle max nλ=dsin(θ). The min occur at sλ=Ndsin(θ) s = +/-1,2, when s/N is integer it is principle max. There are N-2 max between each principal max and N-1 min. As the N is increased the width of the principle max decreases so the spectral resolution increase.
Apr
21
comment Does the EXAFS oscillations occur when ultrashort x-ray pulse is used? Electron with a 50eV kinetic energy will travel in 0.1fs 4.2 Angstroms
Thank you. I guess that my next question is the spectrum of the x-ray required to be monochromatic. I basically dont understand the electron wave interference picture and the nature of the EXAFS oscillation and ask what if blindly. What I am trying to understand is does the electron has to return to the absorbing atom, to modify the absorption, and what if the auger decay happens before the electron returns. Is timing anyhow limiting anything.
Nov
11
comment What spin-statistics is a magnetic monopole expected to obey?
No. But short answer will be best :)
Oct
27
comment What limits laser pulse duration to single cycle?
Thanks. But why is the one cycle the limit. What would be wrong with half cycle ? Is it bandwidth problem or propagation that sets the limit ?
Oct
15
comment Photoelectric effect high frequency limit?
I guess the work function will also change increasing the energy. Might be wrong but at high energy only the core electrons will have high enough cross section to interact with the photons. The question is if the binding energy of the most tightly bound electron is 1000eV let say, would a photon do anything to the material if it has significantly higher energy and do not interact anymore?
Oct
15
comment Max temperature that can be obtained from radiation source when nonlinear interaction with matter is important?
There are many issues, but the question is about the temperature limit and the entropy.
Oct
14
comment Max temperature that can be obtained from radiation source when nonlinear interaction with matter is important?
Here the re-radiation will come from electrons returning to their ions and radiation is at 24eV and 54eV lets say for simplicity. It looks hotter somehow to me.
Oct
14
comment Max temperature that can be obtained from radiation source when nonlinear interaction with matter is important?
Sun was an example, the heating is through radiation away from the source.
Oct
14
comment Max temperature that can be obtained from radiation source when nonlinear interaction with matter is important?
Not related to the question. Any wavelength is ionizing radiation provided it can have the peak intensity to overcome the binding potential of the electron.
Oct
8
comment Two balls falling one above the other
hep.physics.wayne.edu/~harr/courses/5200/f07/lecture24.htm here is your solution
Sep
9
comment What is the mass in $\vec{\nabla}\cdot \vec{B}_g=\text{something}$ called if it could be non-zero?
Thank you. Does it have a name so far, is it an energy .. In theory does it need to be extremely heavy or dense in analogy the magnetic monopole ?
Sep
9
comment Energy conservation in plane wave
Would a single photon interact with itself to create this pattern .. ?
Sep
9
comment Energy band diagram for solid state: what is the meaning of $k$?
Thanks. It is quite abstract as thinking of wave vector. I wanted to understand how can I populate a specific band at some k location with light. And what is the meaning of k=0 these states are not allowed for particle in a box because of the uncertainty principle ..
Jun
23
comment Do you age at different rate at different speed?
Thank you. No would mean velocity matters and same physics do not guarantee same time intervals in different rest frames.
Jun
20
comment Frame of reference of the photon?
Thanks.So there is no such frame, because it is assumed that c is same in all frames and a photon will move with c in its own frame. So photon could not exist at other speed. So it means that we could not know from existing theories how the photon sees the universe, so we can say the photon is "not observer"..
Jun
20
comment Frame of reference of the photon?
Nope. It is not..