Hi John,
That is an excellent first spectrum! Anyone starting out in spectroscopy would be very pleased with that. It shows that all of the basics including instrument response have worked as they should. You may as well crop the spectrum at a slightly shorter wavelength as it looks like it is just noise at the far left, but that is a minor point.
To be honest I hardly ever use the “Dispersion” button on tab 5, as the wavelength calibration is usually performed spot on in tabs 3 and 4. I did take a look at the dispersion in tab 5 last night, and it did appear to be populated, but that was in ISIS v5.5.2. It will be interesting to see what others post, but it may be that even if it is not populating you can get by without it, at least for now. What I’m not sure is whether this is an undetected bug, or something to do with how ISIS is used like a setting.
You may also find you get different behaviour with the neon calibration image, if you select ALPY with Calibration module. Though I’m not sure.
Regardless, you are already getting useful spectra with the processing you are doing.
Best wishes,
Andy