3 Apr 2020

1. Motorised grism

NE brought up motorised prism now that other optics have been selected. SAAO astronomers are of the opinion that we don’t need to motorise and prefer keeping it simple. SB suggests we just have it on a manual hand-adjustable rotation/translation stage. LJMU can optimise in lab where they think is best and we then have the option to manually adjust it on sky if we want to. SAAO agree on that approach.

2. Slit

SAAO would like a stepped slit. Three widths if possible.

SB to check with Iain if the full 10arcmin is usable i.e. if image quality is good at the edges.

HW to check with galactic astronomers if steps are a problem for their non-point sources.

Not a big risk item as SAAO can manufacture a new slit if necessary.

3. Mechanical

EL working on physical integration document, cable interfaces, cable management etc

All discussed 5 degree tilt. Do we want to keep 0 deg tilt mounting holes? Defer decision till just before manufacturing.

HG requests that places for securing cables be visible on the mechanical model. Cabling as far as possible as well, so that SAAO electronics personnel can advise.

Do we need cooling? The camera has attachments for water/glycol circulation. NE to check whether this is required. Cooling pipes should point downwards for as much of the instrument's travel as possible.

4. Software operations concept description

Retha wrote a high level OCD discussing expected user interaction with the software. This can be fleshed out in future as needed.

5. Calibration arc lamp

Arc lamps are not the exact same model as on SPRAT as those are not available anymore

Product sheets for Xenon lamp

6. Design review

Target 17 April

Grism changes won't necessarily be in, as this is a late change

Focus is physical configuration of instrument ("advanced concept review")