Design of the fiber optic support system and fiber bundle accelerated life test for VIRUS

The Visible Integral-field Replicable Unit Spectrograph (VIRUS) consists of a baseline build of 150 identical spectrographs (arrayed as 75 units, each with a pair of spectrographs) fed by 33,600 fibers, each 1.5 arcsec diameter, deployed over the 22 arcminute field of the upgraded 10 m Hobby-Eberly Telescope (HET). The goal is to deploy 96 units. VIRUS has a fixed bandpass of 350-550 nm and resolving power R~700. VIRUS is the first example of industrial-scale replication applied to optical astronomy and is capable of spectral surveys of large areas of sky. The method of industrial replication, in which a relatively simple, inexpensive, unit spectrograph is copied in large numbers, offers significant savings of engineering effort, cost, and schedule when compared to traditional instruments.The main motivator for VIRUS is to map the evolution of dark energy for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX ‡ ) using 0.8M Lyman-α emitting galaxies as tracers. The full VIRUS array is due to be deployed in late 2011 and will provide a powerful new facility instrument for the HET, well suited to the survey niche of the telescope. VIRUS and HET will open up wide field surveys of the emission-line universe for the first time. We present the design, cost, and current status of VIRUS as it enters production, and review performance results from the VIRUS prototype. We also present lessons learned from our experience designing for volume production and look forward to the application of the VIRUS concept on future extremely large telescopes (ELTs). * The Hobby -Eberly Telescope is operated by McDonald Observatory on behalf

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“…The design of the test is described in Ref. 47, along with a description of the fiber cable routing on the telescope. Figure 6.…”

Section: Integral Field Unit Cablesmentioning

confidence: 99%

VIRUS: a massively replicated 33k fiber integral field spectrograph for the upgraded Hobby-Eberly Telescope

et al. 2010

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“…MDO also retains responsibility for the design of several instrumentation components, telescope controls, site modifications, and components within the PFIP. They have contracted the Center for Electromechanics (CEM) at the University of Texas at Austin to undertake the design and manufacture of the new tracker, a support system for HETDEX fiber optic bundles 4 , and a support structure for VIRUS 5 . MDO has also contracted the University of Arizona Optical Sciences Center to design and produce the WFC.…”

Section: Tracker Design Participantsmentioning

confidence: 99%

Collaborative engineering and design management for the Hobby-Eberly Telescope tracker upgrade

et al. 2010

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The engineering and design of systems as complex as the Hobby-Eberly Telescope's* new tracker require that multiple tasks be executed in parallel and overlapping efforts. When the design of individual subsystems is distributed among multiple organizations, teams, and individuals, challenges can arise with respect to managing design productivity and coordinating successful collaborative exchanges. This paper focuses on design management issues and current practices for the tracker design portion of the Hobby-Eberly Telescope Wide Field Upgrade project. The scope of the tracker upgrade requires engineering contributions and input from numerous fields including optics, instrumentation, electromechanics, software controls engineering, and site-operations. Successful system-level integration of tracker subsystems and interfaces is critical to the telescope's ultimate performance in astronomical observation. Software and process controls for design information and workflow management have been implemented to assist the collaborative transfer of tracker design data. The tracker system architecture and selection of subsystem interfaces has also proven to be a determining factor in design task formulation and team communication needs. Interface controls and requirements change controls will be discussed, and critical team interactions are recounted (a group-participation Failure Modes and Effects Analysis [FMEA] is one of special interest). This paper will be of interest to engineers, designers, and managers engaging in multi-disciplinary and parallel engineering projects that require coordination among multiple individuals, teams, and organizations.

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Wind loading analysis and strategy for deflection reduction on HET wide field upgrade

et al. 2010

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Wind loading can be a detrimental source of vibration and deflection for any large terrestrial optical telescope. The Hobby-Eberly Telescope * (HET) in the Davis Mountains of West Texas is undergoing a Wide Field Upgrade (WFU) in support of the Dark Energy Experiment ‡ (HETDEX) that will greatly increase the size of the instrumentation subjected to operating wind speeds of up to 20.1 m/s (45 mph). A non-trivial consideration for this telescope (or others) is to quantify the wind loads and resulting deflections of telescope structures induced under normal operating conditions so that appropriate design changes can be made. A quasi-static computational fluid dynamics (CFD) model was generated using wind speeds collected on-site as inputs to characterize dynamic wind forces on telescope structures under various conditions. The CFD model was refined until predicted wind speed and direction inside the dome agreed with experimental data. The dynamic wind forces were then used in static loading analysis to determine maximum deflections under typical operating conditions. This approach also allows for exploration of operating parameters without impact to the observation schedule of the telescope. With optimum combinations of parameters (i.e. dome orientation, tracker position, and louver deployment), deflections due to current wind conditions can be significantly reduced. Furthermore, the upper limit for operating wind speed could be increased, provided these parameters are monitored closely. This translates into increased image quality and observing time.

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Design of the fiber optic support system and fiber bundle accelerated life test for VIRUS

Cited by 7 publications

References 9 publications

VIRUS: a massively replicated 33k fiber integral field spectrograph for the upgraded Hobby-Eberly Telescope

VIRUS: a massively replicated 33k fiber integral field spectrograph for the upgraded Hobby-Eberly Telescope

Collaborative engineering and design management for the Hobby-Eberly Telescope tracker upgrade

Wind loading analysis and strategy for deflection reduction on HET wide field upgrade

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