WEAVE slit head interface plate

© Photographs by Rik ter Horst

Words are not enough, to describe this beautiful piece of milling art. What we see here is the mechanical interface on which one of the four fibre-populated slit-heads will be positioned.

A slit-head holds 609 to 960 optical fibres, each of which is placed at a particular position in the focal plane of the telescope, to collect the light from a particular celestial object like a star or a galaxy. It then accurately guides the light from these fibres into the WEAVE multi-object spectrograph.

Back to the piece of art: what strikes us are the sharp edges, located in deep pockets, the smooth machined planes and neatly chamfered edges. The part provides stiffness (and thus position accuracy) to the slit-head, and suppresses any stray light by means of the multi-staged baffle (the sharp edges).

In the last two images, we see the part coated with optical black paint (SKYMAP 35), again suppressing stray light from the fibres. Obviously, that is a little less photogenic than the uncoated part.

Oh, before I forget; it was made by our best people.