probability density vs energy

Asked by alexandra

Hello!
As a result of simulation I have a picture: probability density (counts/eV.sr.electron) vs energy(eV). Can you explain what means:
counts-
sr-
electron-
Thank you so much.
Best wishes, Sasha.

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Philippe Pinard (philippe.pinard) said :
#1

The "probability density" is effectively the x ray count rate. A spectrum is made of several energy channels (i.e. bins). The probability density gives you the number of x-rays collected by a detector in each channel. This quantity is normalized by the number of electrons (1/electron), the solid angle of the detector (1/sr) and the energy width of each channel (1/eV).

If you want to compare the simulated intensites with experimental ones, you will need to multiply the simulated intensity by the following factor:

f = solid_angle * energy_channel_width * beam_current * live_time * detector_efficiency / ELECTRON_CHARGE

solid_angle: the solid angle of your EDS detector (sr)
energy_channel_width: the energy width of the channels in your EDS spectrum (eV)
beam_current: the beam current used in the acquisition (A)
live_time: live time of EDS spectrum (s)
detector_efficiency: efficienty of your EDS detector
ELECTRON_CHARGE: 1.60217646e-19 C

The same applies to the intensity reported in the emitted and generated intensity tables. The only exception is that the value is not normalized by the energy width. In these tables, the x-rays are not collected in bins but are counted based on their transition (Ka, La, etc.).

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alexandra (botyachkova-alexandra) said :
#2

thank you so much!

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alexandra (botyachkova-alexandra) said :
#3

Hello!
transmitted photons picture is a probabylity density vs energy, so

probabylity density 1/(eV particle)

probabylity density- number of photons,
eV-energy of each channel
particle-?????

thank you!

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Philippe Pinard (philippe.pinard) said :
#4

probability density: number of photons
eV: energy of each channel
particle: number of simulated electrons

The term "particle" is confusing it should be "electron".

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