Wednesday, September 11, 2013

Assorted Cabling & HS Mode Calibration Options

David & Luke kept busy today connecting up as many hoses & cables & wires as possible - starting with the Cryotigers (the shiny pipes), SDSU controllers (gold boxes) & power supplies (grey boxes) for the CCDs (to name but a few).

Cable ties also featured rather prominently in the day's proceedings!

Here's where everything from the HRS enclosure makes its way through the wall into the electronics room.

The claim is that all this was quite hard work, but this shot would seem to indicate otherwise ;)

The robustness of Keith's stress-management protocol is to be admired - note how he manages to seamlessly combine the art of crimping of wires with an ability to bask contentedly beneath artificial light in a black room.

We'd planned to put the rest of the optics into the tank today so the VPH gratings were mounted on their stands.  But with all the cabling work going on, it was deemed better to keep the tank closed & get on with other jobs, such as setting up all the bits on the small optical bench next to the tank.

While unpacking various boxes looking for specific bits & pieces, the rig for testing the focal ratio degradation (FRD) of the fibres made its debut.  Very cool that it even has an onboard filter wheel & a set of easy-to-change F-stops!  We definitely need one of these...

Here's the lamp box for the simultaneous Thorium Argon (ThAr) injection for the HS mode being assembled.  Light from the glowing gas inside the glass tube will emerge through the lens on the right-hand side of the box & be fed into either of the HS mode fibres.

The black contraption extending from the lower left corner of the pic below is the linear stage that will carry the instrument's iodine cell & various fold mirrors.  The iodine cell is another option in HS mode for obtaining better wavelength calibration as it will result in a forest of iodine absorption features being superimposed on the object spectra.  All the better to find exo-planets with!!

One will have the choice of using either the iodine cell or the simultaneous ThAr injection in the HS mode.  The selection will be made by moving the stage assembly so that the fold mirrors feed light from the appropriate system into the chosen fibre.

The clear glass tube to the left of centre in the pic below is the iodine cell & the two connectors on the frame allow the cell to be heated above 35°C in order to get the iodine to sublimate.

The cell is enclosed in a thermally insulated box with windows on either end to allow the light through.

Stay tuned for more optical thrills tomorrow ;)

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