4MOST - 4-metre Multi-Object Spectroscopic Telescope
4-m Multi-Object Spectroscopic Telescope

Long Fibre Feed installation at CTS and connection to AESOP

by Henri Boffin on 2023-07-25

The 4MOST Fibre System, deployed at the Cassegrain Test Stand (CTS) at AIP. On the ground is the fibre strain relief assembly and the three transport cases for the slit assemblies. The elevation chain connects to the CTS structure and the fibre route continues inside the cable rotator.

The 4MOST System Integration is proceeding nicely according to plan. On 19 July 2023, the final optical fibre relay with all the science and auxiliary fibres (aka, the Long Fiber Feed or LFF) was connected to the Fibre Positioner AESOP. This is an important milestone on the path towards full system integration in Potsdam. Please see the attached photos courtesy of Andreas Kelz (AIP).

"After the Fibre-Feed system has been built and assembled, it successfully passed Local Acceptance Review in May 2023," said LFF Workpackage Manager, Andreas Kelz. "Subsequently, the fibre system was folded, packed and transported across the AIP campus to the main integration hall, where it has been integrated into the Cassegrain Cable Wrap and mounted onto the Cassegrain Test Stand. The fibre elevation chain and strain relief units are mounted in the same positions as on VISTA. Finally, all 181 fibre connectors have been plugged to the backside of the AESOP positioner."

All fibre connectors (i.e., the 168 for science fibres, 12 guide cables and 1 fiducial connector) are plugged to the backside of the AESOP positioner. Also, all service cables and cooling lines (three o'clock) are connected to AESOP and the limit switches.