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Register a new userAutomated testing of optical fibres: towards the design of the Maunakea Spectroscopic Explorer Fibre Transmission System
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We present the results of an automated fibre optic test bench constructed at the University of Victoria as part of the Maunakea Spectroscopic Explorer (MSE) Fibre Transmission System (FiTS). In preparation for MSE-FiTS, we have begun characterizing the focal ratio degradation (FRD) of candidate multi-mode fibres with the ultimate goal of testing all ~4000 MSE fibres. To achieve this, we have built an optical bench to perform an automated version of the collimated beam test. Herein we present the design of the bench and discuss the automation of components by introducing the Big FiTS Fibre Wrapper (Big FFW), our open-source automation software. We conclude with the results of tests performed using the Big FFW on a sample of candidate fibre, comparing the Big FFW results against those found using manual methods. Our results suggest that the candidate MSE fibre meets the science requirement of < 5% FRD at f=2 and less than 1% disagreement between both measurement methods.
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The Maunakea Spectroscopic Explorer is a next-generation massively multiplexed spectroscopic facility currently under development in Hawaii. It is completely dedicated to large-scale spectroscopic surveys and will enable transformative science. In this white paper we summarize the science case and describe the current state of the project.
Optical designs are presented for the Maunakea Spectroscopic Explorer (MSE) telescope. The adopted baseline design is a prime focus telescope with a segmented primary of 11.25m aperture, with speed f/1.93 and 1.52deg field-of-view, optimized for wavelengths 360-1800nm. The Wide-Field Corrector (WFC) has five aspheric lenses, mostly of fused silica, with largest element 1.33m diameter and total glass mass 788kg. The Atmospheric Dispersion Corrector (ADC) is of the compensating lateral type, combining a motion of the entire WFC via the hexapod, with a restoring motion for a single lens. There is a modest amount of vignetting (average 5% over the hexagonal field); this greatly improves image quality, and allows the design to be effectively pupil-centric. The polychromatic image quality is d80<0.225/0.445 at ZD 0/60deg over more than 95% of the hexagonal field-of-view. The ADC action allows adjustment of the plate-scale with zenith distance, which is used to halve the image motions caused by differential refraction. A simple design is presented for achieving the required ADC lens shifts and tilts. A two-mirror design was also undertaken for MSE, but was not selected. This is a 12.3m F/2.69 forward Cassegrain design, with a 2.75m diameter M2, and three silica lenses, of largest diameter 1.33m. The field-of-view is again 1.52deg. The f/0.95 primary makes the design remarkably compact, being under 10m long. The ADC action involves a small motion of M2 (again via a hexapod), and shifts and tilts of a single lens. The design is effectively pupil-centric, with modest vignetting (5.9% average). The image quality is virtually identical to the prime focus design.
(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is intended as a concise reference guide to all aspects of the scientific and technical design of MSE, for the international astronomy and engineering communities, and related agencies. The current version is a status report of MSEs science goals and their practical implementation, following the System Conceptual Design Review, held in January 2018. MSE is a planned 10-m class, wide-field, optical and near-infrared facility, designed to enable transformative science, while filling a critical missing gap in the emerging international network of large-scale astronomical facilities. MSE is completely dedicated to multi-object spectroscopy of samples of between thousands and millions of astrophysical objects. It will lead the world in this arena, due to its unique design capabilities: it will boast a large (11.25 m) aperture and wide (1.52 sq. degree) field of view; it will have the capabilities to observe at a wide range of spectral resolutions, from R2500 to R40,000, with massive multiplexing (4332 spectra per exposure, with all spectral resolutions available at all times), and an on-target observing efficiency of more than 80%. MSE will unveil the composition and dynamics of the faint Universe and is designed to excel at precision studies of faint astrophysical phenomena. It will also provide critical follow-up for multi-wavelength imaging surveys, such as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation Very Large Array.
The Maunakea Spectroscopic Explorer (MSE) Project is a planned replacement for the existing 3.6-m Canada France Hawaii Telescope (CFHT) into a 10-m class dedicated wide field highly multiplexed fibre fed spectroscopic facility. MSE seeks to tackle basic science questions ranging from the origin of stars and stellar systems, Galaxy archaeology at early times, galaxy evolution across cosmic time, to cosmology and the nature of dark matter and dark energy. MSE will be a primary follow-up facility for many key future photometric and astrometric surveys, as well as a major component in the study of the multi-wavelength Universe. The MSE is based on a prime focus telescope concept which illuminate 3200 fibres or more. These fibres are feeding a Low Moderate Resolution (LMR) spectrograph and a High Resolution (HR). The LMR will provide 2 resolution modes at R>2500 and R>5000 on a wavelength range of 360 to 950 nm and a resolution of R>3000 on the 950 nm to 1300 nm bandwidth. Possibly the H band will be also covered by a second NIR mode from ranging from 1450 to 1780 nm. The HR will have a resolution of R>39000 on the 360 to 600 nm wavelength range and R>20000 on the 600 to 900 nm bandwidth. This paper presents the LMR design after its Conceptual Design Review held in June 2017. It focuses on the general concept, optical and mechanical design of the instrument. It describes the associated preliminary expected performances especially concerning optical and thermal performances.
This short document is intended as a companion and introduction to the Detailed Science Case (DSC) for the Maunakea Spectroscopic Explorer. It provides a concise summary of the essential characteristics of MSE from the perspective of the international astronomical community. MSE is a wide field telescope (1.5 square degree field of view) with an aperture of 11.25m. It is dedicated to multi-object spectroscopy at several different spectral resolutions in the range R ~ 2500 - 40000 over a broad wavelength range (0.36 - 1.8{mu}m). MSE will enable transformational science in areas as diverse as exoplanetary host characterization; stellar monitoring campaigns; tomographic mapping of the interstellar and intergalactic media; the in-situ chemical tagging of the distant Galaxy; connecting galaxies to the large scale structure of the Universe; measuring the mass functions of cold dark matter sub-halos in galaxy and cluster-scale hosts; reverberation mapping of supermassive black holes in quasars. MSE is the largest ground based optical and near infrared telescope in its class, and it will occupy a unique and critical role in the emerging network of astronomical facilities active in the 2020s. MSE is an essential follow-up facility to current and next generations of multi-wavelength imaging surveys, including LSST, Gaia, Euclid, eROSITA, SKA, and WFIRST, and is an ideal feeder facility for E-ELT, TMT and GMT.
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