Design and implementation of an improved chilled water glycol system for GeMS - CANOPUS thermal enclosures

CANOPUS is the facility instrument for the Gemini Multi Conjugate Adaptive Optics System (GeMS) wherein all the adaptive optics mechanisms and associated electronic are tightly packed. At an early stage in the pre-commissioning phase Gemini undertook the redesign and implementation of its chilled Ethylene Glycol Water (EGW) cooling system to remove the heat generated by the electronic hardware. The electronic boards associated with the Deformable Mirrors (DM) represent the highest density heat yielding components in CANOPUS and they are also quite sensitive to overheating. The limited size of the two electronic thermal enclosures (TE) requires the use of highly efficient heat exchangers (HX) coupled with powerful yet compact DC fans. A systematic approach to comply with all the various design requirements brought about a thorough and robust solution that, in addition to the core elements (HXs and fan), makes use of features such as high performance vacuum insulated panels, vibration mitigation elements and several environment sensors. This paper describes the design and implementation of the solution in the lab prior to delivering CANOPUS for commissioning. © 2010 Copyright SPIE - The International Society for Optical Engineering.Fil: Gausachs, Gaston. Gemini Observatorysouthern Operations Center; ChileFil: Bec, Matthieu. Gemini Observatorysouthern Operations Center; ChileFil: Galvez, Ramon. Gemini Observatorysouthern Operations Center; ChileFil: Cavedoni, Chas. Gemini Observatory;Fil: Vergara, Vicente. Gemini Observatorysouthern Operations Center; ChileFil: Diaz, Herman. Gemini Observatorysouthern Operations Center; ChileFil: Fernandez, German Enzo Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; Argentin

GeMS: Gemini MCAO System: current status and commissioning plans

The Gemini Multi-Conjugate Adaptive Optics project was launched in April 1999 to become the Gemini South AO facility in Chile. The system includes 5 laser guide stars, 3 natural guide stars and 3 deformable mirrors optically conjugated at 0, 4.5 and 9km to achieve near-uniform atmospheric compensation over a 1 arc minute square field of view. Sub-contracted systems with vendors were started as early as October 2001 and were all delivered by July 2007, but for the 50W laser (due around September 2008). The in-house development began in January 2006, and is expected to be completed by the end of 2008 to continue with integration and testing (I&T) on the telescope. The on-sky commissioning phase is scheduled to start during the first half of 2009. In this general overview, we will first describe the status of each subsystem with their major requirements, risk areas and achieved performance. Next we will present our plan to complete the project by reviewing the remaining steps through I&T and commissioning on the telescope, both during day-time and at night-time. Finally, we will summarize some management activities like schedules, resources and conclude with some lessons learned

The Gemini South MCAO laser guide star facility: getting ready for first light

The Gemini Observatory is in the final integration and test phase for its Multi-Conjugate Adaptive Optics (MCAO) project at the Gemini South 8-meter telescope atop Cerro Pachón, Chile. This paper presents an overview and status of the laser-side of the

The Gemini MCAO Infrastructure: laser service enclosure and support structure

The Laser Service Enclosure (LSE) is an environmentally controlled ISO 7 clean room designed to house, protect and provide environmental control for the Gemini South multi-conjugate adaptive optics laser system. The LSE is 8.0 meters long, 2.5 meters wide and 2.5 meters high with a mass of approximately 5,100 kg. The LSE shall reside on a new telescope Nasmyth platform named the Support Structure (SS). The SS is a three-dimensional beam and frame structure designed to support the LSE and laser system under all loading conditions. This paper will review the system requirements and describe the system hardware including optical, environmental, structural and operational issues as well as the anticipated impact the system will have on the current telescope performance

Altair at Gemini North : full sky coverage laser AO correction at visible wavelengths

We present two recent upgrades to the Gemini North Adaptive Optics (AO) system, Altair. These two upgrades provide 100% sky coverage for low performance AO suitable for improving the natural seeing by factors of 25% to 3 from blue visible wavelengths (350 nm) through the near infrared (2.5 micron wavelengths). The first upgrade, dubbed LGS + P1 "Super Seeing" mode, allows correction of high order aberrations with an on-axis Laser Guide Star (LGS) while tip/tilt correction is performed with a more distant peripheral wavefront sensor (P1). Most currently operating LGS AO systems are limited in their sky coverage, primarily due to tip/tilt star availability. Although P1 provides sub-optimal tip/tilt correction due to its distance from the science source, its patrol radius allows operation in LGS + P1 mode anywhere in the sky from declinations of +70 degrees to -30 degrees. This mode was offered for science use at Gemini North in 2013A. We present typical performance and use from its first semester in science operation, with a factor 2 to 3 image quality improvement over seeing limited images. The second upgrade is the commissioning of the AO system to correct at visible wavelengths, which is expected to be completed in 2014. In this mode, Altair will feed the Gemini Multi-Object Spectrograph (GMOS), which is an optical imager as well as a long-slit, multi-slit and integral field unit spectrograph. We intend to replace the current Altair science dichroic with a sodium notch filter, passing only the 589nm wavelength light from the LGS to the AO system. The rest of the spectrum from 350 nm to the GMOS red cutoff at 1.1 microns is intended as science capable light. Tip/tilt correction will be performed close to the science target with the GMOS on-instrument wavefront sensor or with P1 as in the P1+LGS mode discussed above. We expect an image quality improvement of 25% in this mode over seeing limited observations. Since exposure time to reach a given signal-to-noise ratio scales roughly as the square of the image quality, these two upgrades represent a substantial efficiency improvement which is available to nearly all targets normally observed at Gemini North.7 page(s

On-sky vibration environment for the Gemini Planet Imager and mitigation effort

The Gemini Planet Imager (GPI) entered on-sky commissioning and had its first-light at the Gemini South (GS) telescope in November 2013. GPI is an extreme adaptive optics (XAO), high-contrast imager and integral-field spectrograph dedicated to the direct detection of hot exo-planets down to a Jupiter mass. The performance of the apodized pupil Lyot coronagraph depends critically upon the residual wavefront error (design goal of 60 nm RMS with 5 mas RMS tip/tilt), and therefore is most sensitive to vibration (internal or external) of Gemini's instrument suite. Excess vibration can be mitigated by a variety of methods such as passive or active dampening at the instrument or telescope structure or Kalman filtering of specific frequencies with the AO control loop. Understanding the sources, magnitudes and impact of vibration is key to mitigation. This paper gives an overview of related investigations based on instrument data (GPI AO module) as well as external data from accelerometer sensors placed at different locations on the GS telescope structure. We report the status of related mitigation efforts, and present corresponding results.Comment: 12 pages,8 figures, Proc. SPIE 9148 (2014