### Author Topic: Formation of Ca II lines  (Read 44 times)

#### EliasRU

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• Posts: 3
##### Formation of Ca II lines
« on: 18. February 2021, 09:06:03 »
Hi
Can someone verify these results from the CaII exercises? These are my plots for the departure coefficient for the ground state and where the line forms (the height at which $$\tau = 1$$.

I think Jonas got the same results as me. Also is it correct to denote the departure coefficient for level $$i$$ as $$b_i$$ ?

Elias

#### EliasRU

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• Posts: 3
##### Re: Formation of Ca II lines
« Reply #1 on: 18. February 2021, 09:09:40 »
Follow-up question: From the departure coefficient plot, i deduced that LTE is valid deep down in the atmosphere, while higher up in the atmosphere (around height $$=1\,\textrm{Mm}$$ or $$\tau = 10^{-5}$$ ) LTE breaks down

#### souvikb

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• Posts: 4
##### Re: Formation of Ca II lines
« Reply #2 on: 25. February 2021, 21:41:40 »
Just for the sake of completeness, I am attaching an additional plot with the departure coefficients for all the levels of Ca.

#### souvikb

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• Posts: 4
##### Re: Formation of Ca II lines
« Reply #3 on: 25. February 2021, 21:44:59 »
Nice work!
You can also play with the Source function if you'd like. I personally do not like the widgets but you are free to use them. But I would urge you to play with it by importing it from output_ray.hdf5

#### souvikb

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• Posts: 4
##### Re: Formation of Ca II lines
« Reply #4 on: 25. February 2021, 21:52:06 »
Can you also show me the plot of Ca II K intensity vs. wavelength?

Did you activate PRD while synthesizing Ca II H&K? These lines are strong resonance lines and the effects of PRD become very important especially in the K2/H2 peaks. So if you have not activated it, set PRD_N_MAX_ITER = 3 in your keyword.input.