How to calculate emittance

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Chinahanxj
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How to calculate emittance

Post by Chinahanxj »

Dear author
I would like to know what formula was used to calculate the value of Xmax in the circled part of this picture. If the reference is made to the circled part in the second figure, this calculation result is incorrect.
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屏幕截图 2026-01-31 000655.png
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FranceDidier
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Re: How to calculate emittance

Post by FranceDidier »

Dear Sir,

Please note that what is plotted is the total size, not the rms size (see image below) and the rms beam size = sqrt(Exxp_nn*bet). Exxp_nn is the rms unnormalised emittance, the one you are pointing to is the normalised one.
emit.png
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Regards,

Didier
Chinahanxj
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Re: How to calculate emittance

Post by Chinahanxj »

However, even when the button click is replaced with the calculated maximum value of X based on the rms size, it still does not match the result obtained from this formula. Could it be that some additional factors have been included in the calculation?
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FranceDidier
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Re: How to calculate emittance

Post by FranceDidier »

Dear Hanxj,

On my side, using you beam parameters, I got SizeX_rms=5.53 mm. Please send me your project files, something is wrong, I'll check for you.

Regards,

Didier
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