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Record W7006565373

Two new wheels for ATLAS

2002· other· en· W7006565373 on OpenAlexaboutno aff

Bibliographic record

VenueCERN Document Server (European Organization for Nuclear Research) · 2002
Typeother
Languageen
Field
Topic
Canadian institutionsnot available
Fundersnot available
KeywordsAtlas (anatomy)Field (mathematics)Set (abstract data type)
DOInot available

Abstract

fetched live from OpenAlex

Juergen Zimmer (Max Planck Institute), Roy Langstaff (TRIUMF/Victoria) and Sergej Kakurin (JINR), in front of one of the completed wheels of the ATLAS Hadronic End Cap Calorimeter. A decade of careful preparation and construction by groups in three continents is nearing completion with the assembly of two of the four 4 m diameter wheels required for the ATLAS Hadronic End Cap Calorimeter. The first two wheels have successfully passed all their mechanical and electrical tests, and have been rotated on schedule into the vertical position required in the experiment. 'This is an important milestone in the completion of the ATLAS End Cap Calorimetry' explains Chris Oram, who heads the Hadronic End Cap Calorimeter group. Like most experiments at particle colliders, ATLAS consists of several layers of detectors in the form of a 'barrel' and two 'end caps'. The Hadronic Calorimeter layer, which measures the energies of particles such as protons and pions, uses two techniques. The barrel part (Tile Calorimeter) consists of sheets of steel to create showers of lower energy particles. These sheets are interleaved with scintillator to sample the energy. However, because of high radiation levels, the end caps use a different technique with copper to create the showers and liquid argon to measure the energy. Both Hadronic End Cap Calorimeters consist of two wheels placed one behind the other. Each wheel is made from 32 wedge-shaped modules consisting of 25-mm thick copper plates for the front wheel and 50-mm thick plates for the rear wheel. The modules have been built by groups in Western Canada, Munich (Germany), Dubna and Protvino (Russia), with contributions to the electronics equipment by Kosice (Slovakia), while a group from Nanjing (China) has procured part of the copper and contributed to the equipment for assembling the wheels. The 8-mm gaps between the copper plates house three large wedge-shaped HV electrodes, produced by a collaboration from Mainz, TRIUMF, and the Lebedev Institute. The electrodes are separated by honeycomb mat spacers to ensure a well defined geometry and mechanical stability. Once immersed in liquid argon at -185 C, the inner electrode will collect the electric charge left by the charged particles that ionise the liquid. Fast radiation-hard GaAs-based amplifiers, which have been specially designed at the Max Planck Institute of Physics in Munich, are installed at the outer radius of the wheel. They have been pre-tested to be fully operational at both room temperature and liquid argon temperature. The 70-tonne front and 90-tonne rear wheels were initially assembled from pre-tested modules on a table 3 m above ground and later rotated to the vertical position by a special device designed and built in Canada. The assembly of the first complete wheel took 45 days - two days less than scheduled. Construction of the second wheel was completed in November and all four wheels should be finished by summer 2003. Of the 128 modules required to make the four wheels only two remain to be manufactured and all but 12 have been pre-tested at liquid argon temperatures in the test beam area at CERN. The Electromagnetic Calorimeter, which measures the energies of electrons and photons, and the Forward Calorimeter close to the beam pipe, will also use liquid argon, so a common cryostat structure will keep the liquid argon at -185 C. The first such cryostat, provided by a French-German consortium, will be filled with an Electromagnetic End Cap Calorimeter, a Forward Calorimeter and two wheels of the Hadronic End Cap Calorimeter and cooled down in February 2004. The second cryostat is expected to follow one year later.

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.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.003
metaresearch head score (Gemma)0.004
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesInsufficient payload (model declined to judge)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.373
Threshold uncertainty score0.894

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0030.004
Meta-epidemiology (narrow)0.0010.001
Meta-epidemiology (broad)0.0010.002
Bibliometrics0.0020.002
Science and technology studies0.0030.001
Scholarly communication0.0060.007
Open science0.0030.008
Research integrity0.0020.004
Insufficient payload (model declined to judge)0.3730.241

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 head0.039
GPT teacher head0.293
Teacher spread0.253 · 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

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

Study designBench or experimental
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2002
Admission routes1
Has abstractyes

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Same venueCERN Document Server (European Organization for Nuclear Research)→French-language works237,207→