28 May A busy Saturday in the spectrometer room

The NIR team put in a loooong Saturday – tackling various tasks & snapping some particularly cool photos of the instrument that now contains all of its optics.

The TIC light feed was aligned, so that light can be injected into the instrument.

That then allowed them to align the collimator, to centre the fibre spots on the detector. After installing the grating they could check the (warm) camera optical alignment using neon arc spectra. At best focus there was <100 microns of focal plane tilt, so that was good enough to go cold without making any further adjustments (other than a 1 mm re-spacing of the dewar gap for cold operation).

Some plastic shrouds were installed to shield the instrument from the air flow within the enclosure.

Here you can see where the TIC attaches to the collimator

& there was plenty of other prep to be done ahead of cooling the system down, including hooking up air purge lines for the optics.

Spot the mildly dispersed Kurt, seen here through the 950 l/mm VPH grating!  The silver vacuum hose is permanently attached to the dewar so that it can be pumped on at any stage, without having to warm everything up first.  It had to be carefully suspended so that it stays out of the way of the camera that articulates according to the grating angle selected.

A number of night-owl cameras were also installed within the enclosure – these are really handy as they can be used to spy on the mechanisms while the system’s cold.

Various views of the instrument from inside the cold enclosure

The cooling process was started at about 10pm, so it should be down to -40C by dinner time tomorrow…