The first Spectrograph Module was re-assembled at Subaru Telescope


Earlier we reported that one of the PFS instruments, the first Spectrograph Module was shipped to Hawaii Observatory, National Astronomical Observatory of Japan in Hawaii (see here). More recently, the module has been transported to Subaru Telescope at the summit of Maunakea, and re-assembled there.

PFS Spectrograph Module consists of ten and several assemblies such as camera units, grating assemblies, and the bench. Among them, all assemblies but near-infrared camera were shipped to Subaru Telescope.

Crates heading to the Subaru Telescope.

25 November 2019, 11 crates of Spectrograph assemblies and tools were transported to the summit. Since there were many crates, Subaru staff started loading them early morning. The fiber-slit assembly, which was found to have a problem with some fibers with low transmission, was repaired first at Hilo base and transported separately after repair work.

Fiber-slit assembly under repair by Brazilian team.

In the following week, the crates were delivered to the fourth floor of the dome building. Then LAM and Subaru colleagues started re-assembly. To begin with, they arranged the control cable, coolant line and vacuum conduits. Then they installed the optical bench, on which optics components such as the cameras and gratings were re-assembled.

We had to replace a few control devices which were broken during the shipping. Bad weather made us evacuate from the summit and suspend re-assembly work. However, within 2.5 weeks, we finished re-assembly and managed to check functions by cooling down the cameras. As a result,  we found alignment was not so different than that before shipping.

SM1 re-assembled in the clean room of Subaru Telescope

In January, LAM will start to carry out performance test intensively and see if its performance at Subaru telescope is as good as before shipping.

This video summarize our activity of SM1 re-assembly. Please enjoy!

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