Figures 10-11 .
John Pazder and the first three optics for the GHOST spectrograph .
Credit : Greg Burley , NRC-H
ager Peter Young , Software Engineer Jon Nielson , and Project Scientist Mike Ireland — all from the Australian National University . Peter and Jon presented a paper and poster on how GHOST will be controlled with software using the Gemini Instrument Application Programmer Interface ( GIAPI ), the newest Gemini software framework . Mike ’ s paper and poster showed the precision radial velocity error budget for the instrument , obtained from end-to-end simulations . Although GHOST was not designed for radial velocity precision , the 10 meters per second requirement is feasible ; GHOST may also achieve a significantly higher performance than this .
John Pazder , Project / Optical Engineer at Canada ’ s National Research Council- Herzberg ( NRC-H ), presented a paper and poster covering the optical design of the bench-mounted spectrograph and the predicted resolution and efficiency for the spectrograph . The following GHOST project team members were also in attendance : Project Manager / Detector Engineer Greg Burley , from NRC-H ; Optics Engineer Ross Zhelem , from AAO ; and Instrument Scientist Steve Margheim , Systems Engineer Andrew Serio , and Project Manager David Henderson , from Gemini .
The NRC-H team building the bench-mounted spectrograph subsystem recently received the first major optical components from vendors . The first three optical blanks ( Figures 10 and 11 ) came from Schott in Germany and were inspected at NRC-H prior to being shipped out for further processing : grinding , polishing , and coating at another vendor . These optics make up the spectrograph ’ s white pupil relay section . We expect the build phase , the project ’ s longest phase , to conclude at the end of 2017 , with commissioning at the telescope in 2018 .
New Laser Guide Stars Coming to Both Gemini Telescopes
Gemini offers Laser Guide Star ( LGS ) adaptive optics ( AO ) at both Gemini telescopes – with Altair in the North , and as an integral part of the Gemini Multi-conjugate adaptive optics System ( GeMS ) at Gemini South . The lasers are projected into the sky where they excite a small patch of sodium ions in the ionosphere . The re-radiated light from the sodium layer then forms an artificial “ guide star ” ( or stars for GeMS ) that the AO system uses for wavefront reference .
Our existing diode-pumped , solid-state lasers were state-of-the-art when developed , but that was well over a decade ago ; they are now very difficult and expensive to maintain and operate and require significant effort — from both in-house specialists and external contractors — to keep them calibrated and operational at useful power levels .
Recently , a new technology has emerged that presents us with an opportunity to upgrade our lasers . Called Raman fiber laser amplification , it is in widespread use in fiber optics communication systems . A partnership between Toptica Photonics in Germany and MPB Communications in Canada , has applied this technology — licensed from the European Southern Observatory ( ESO ) — in LGS systems that use their SodiumStar laser system ; Gemini selected this option after an open competition to provide new lasers for Gemini . The SodiumStar system provides a “ turn-key ” laser , with very low maintenance requirements , and is very simple to operate .
We are planning to put SodiumStar lasers on both Gemini telescopes , starting at Gemini South . The project is well under way with the laser in production at Toptica and Factory Acceptance Testing scheduled for late
50 GeminiFocus January 2017 | 2016 Year in Review