Continuous SHG

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Jean-Francois
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Continuous SHG

Post by Jean-Francois »

Hello,

After reading the other topic (viewtopic.php?t=41041), I can present one of my (old) idea for a continuous scanning of the sun.
Here the layout:
SolEx_Dove_100-1000_a.jpg
SolEx_Dove_100-1000_a.jpg (59.97 KiB) Viewed 825 times
SolEx_Dove_100-1000_b.jpg
SolEx_Dove_100-1000_b.jpg (89.57 KiB) Viewed 825 times
The design is showed with a 100/1000 telescope. The first reflection is on the Herschel prism. The second reflection is a standard 90°folding mirror.
Both parts are fixed to the telescope focuser. All other part are independent and fixed on the telescope tube (exactly the same Maurice did it with his SHG setup).

For the full sun imaging, then with the Sol'Ex a smaller telescope is necessary, Here with a 72/432 telescope:
SolEx_Dove_72-432_a.jpg
SolEx_Dove_72-432_a.jpg (85.02 KiB) Viewed 825 times
Now the difference in my design ... 2 lenses and a Dove prism are used for rotating the sun disc image. In the Zemax model, I insert only 2 paraxial lenses. After that it is the normal Sol'Ex.
Now how to scan ? ... The telescope follows the sun and stays centered on the sun (so no scan in RA or DEC).
The scan is performed by rotating the Dove prism along his long axis. The sun disc rotates 2x the prism rotation.
The slit seems to rotate on the sun disc. What that mean ? ... a new processing software has to be written :-)

What would be the advantages ? ... no requirement on the mount scanning. The scanning is continuously.
One disadvantage is the center of the sun disc is all the time at the same place on the slit.
The highest spatial resolution is at the rim of the sun disc. So ideal for the protuberances imaging.

So this idea was ~2 year old and not used ... if somebody will try ?

Best regards,
Jean-Francois


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Re: Continuous SHG

Post by thesmiths »

Why not rotate the slit and grating by 90 degrees and simply have the 2nd mirror rotatable so as to scan the solar disk across the slit as usual?


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rsfoto
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Re: Continuous SHG

Post by rsfoto »

Hi,

How big must the dove prism be?


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

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