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Record W7011491996

Mechanical and optical studies for an extremely large telescope mid-infrared instrument

2021· dissertation· en· W7011491996 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

aboutThe title or abstract carries a Canadian signal from the geographic lexicon.
no affNo Canadian affiliation: this work is invisible to an affiliation-only frame.
No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Bibliographic record

VenueRepositório da Universidade de Lisboa (University of Lisbon) · 2021
Typedissertation
Languageen
FieldEngineering
TopicEngineering and Materials Science Studies
Canadian institutionsnot available
Fundersnot available
KeywordsTelescopeOptical telescopeHexapodPhase (matter)Primary mirrorInfrared telescopeSpectrographAdaptive optics
DOInot available

Abstract

fetched live from OpenAlex

Extremely Large Telescopes are considered worldwide as one of the highest priorities in ground-based astronomy, since they have the potential to vastly advance astrophysical knowledge. ESO is building its own Extremely Large optical and infrared Telescope, the ELT. This new telescope will have a 39m main mirror and will be the largest optical telescope in the world, able to work at the diffraction limit. METIS, one of the first light instruments of the ELT, has powerful imaging and spectrographic capabilities on the thermal wavelengths. It will allow the investigation of key properties of a wide range of celestial objects. METIS is an extremely complex instrument, weighing almost 11t, and requiring high positioning and steering precisions. Here I present the ELT’s METIS’ Warm Support Structure. It consists of a seven leg elevation platform, an hexapod capable of providing METIS with sub-millimetre and arcsecond positioning and steering resolutions, and an access platform where personnel can perform in-situ maintenance activities. The structure weighs less than 5 t and is capable of surviving earthquake conditions with accelerations up to 5g. The current design is supported by FEM simulations in ANSYS®, and was approved for Phase C. I also study the impact of the Talbot effect on the optics of METIS. This near-field effect reimages high frequencies of the phase into the amplitude, having the potential to harm the High contrast imaging (HCI) modes of the instrument. I analyse the phase errors resulting from the surface form errors of optical elements and conclude that they have an impact of less than 3% on the amplitude considering the current specifications. Finally, I develop a way of replicating the behaviour of a vortex coronagraph with raytracing software. I use this to assess the straylight caused by this kind of coronagraphs.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.609
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.021
GPT teacher head0.236
Teacher spread0.215 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it