Graduate Determination of electron temperature in an ion source

Thread starter HeavyIon
Start date Apr 14, 2023
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Determination Electron Ion Source Temperature

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The discussion focuses on determining the electron temperature in an ion source using the Electron Cyclotron Resonance (ECR) method. The Saha equation is proposed as a potential tool for this calculation, with the McWhirter criterion provided to assess its applicability. Participants seek clarification on the appropriate value of ΔE, which represents the energy gap for singly charged helium, to use in the formula. Understanding this value is crucial for accurate temperature determination. The conversation emphasizes the need for precise parameters to ensure reliable results in electron temperature calculations.

Apr 14, 2023

HeavyIon

How to correctly determine the temperature of electrons in an ion source based on ECR?
Is it possible to use the Saha equation?
##\frac{n_en_i}{n_a}=\frac{g_eg_i}{g_a}*3*10^{21} T^{3/2} e^{-J/T}##
Using the search, I found the McWhirter criterion for the applicability of the formula above:
##n_e >>1.6*10^{12}T^{1/2}*\Delta E^3##
Here ##n_e## is the electron density in ##cm^{-3}##, T is the electron temperature in ##eV##, and ##\Delta E## is the largest energy gap between upper and lower energy states that corresponds to one of the spectral lines used. I don't quite understand what \Delta E value should be considered in my case? I'm getting singly charged helium.

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