MétaCan
Menu
Back to cohort
Record W3126217197

Cosmic muon-induced neutrons in the SNO+ water phase

2020· dissertation· en· W3126217197 on OpenAlexaboutno aff
B. Liggins

Bibliographic record

VenueQueen Mary Research Online (Queen Mary University of London) · 2020
Typedissertation
Languageen
FieldPhysics and Astronomy
TopicDark Matter and Cosmic Phenomena
Canadian institutionsnot available
Fundersnot available
KeywordsMuonCOSMIC cancer databaseNuclear physicsCosmic rayNeutronPhysicsPhase (matter)Particle physicsRadiochemistryAstronomyChemistry
DOInot available

Abstract

fetched live from OpenAlex

The SNO+ experiment is the successor to the Nobel prize winning SNO experiment.SNO+ will ultimately search for neutrinoless double beta decay in 130 Te. 1.3 tonnes of 130 Te will be dissolved into 780 tonnes of organic liquid scintillator (LAB).9300 photo-multiplier tubes (PMTs) will observe the loaded scintillator held in an acrylic vessel of 6 m radius.This final stage of operation is proceeded by a number of preparation periods, during which other physics may be probed.This thesis reports the status of a physics measurement in the first phase of operation with a detector filled with ultra-pure water.The work aims to measure the production of cosmic muon induced neutrons that spallate in water and capture on hydrogen releasing a 2.2 MeVgamma ray.This process presents as a large background in many weak signal searches, such as dark matter searches, knowledge of the induced neutron production rate will inform both theoretical and experimental considerations.All components of the analysis developed to date are detailed.A low level PMT anomaly detection system is motivated and implemented, it is shown to remove high noise and inactive PMTs from data, applicable to general SNO+ analyses but especially important for low energy events.Muon event reconstruction is implemented, resulting in a track length error of ≤5% for tracks lengths > 10 m.A muon selection focused on a purity is detailed, producing a sample of muon candidates consistent with the rate observed | viii in SNO.A neutron candidate selection with a purity of ≈99% is also defined.After applying both selections to a custom data processing, the neutron capture time is measured to be 134 ± 16 µs which is inconsistent with the expected capture time of 206.03 ± 0.44 µs as measured by an 241 Am 9 Be calibration source in SNO+.This inconsistency is shown to be a result of electronic instability at short times after a cosmic muon event.This electronic instability is a previously unknown effect, leaveing the analysis incomplete and requiring future work.

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)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
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 score0.007
Threshold uncertainty score0.016

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0010.000
Scholarly communication0.0010.000
Open science0.0000.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0050.000

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 head0.032
GPT teacher head0.314
Teacher spread0.282 · 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.

The models applied no category: nothing in the taxonomy fit this work.
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
Published2020
Admission routes1
Has abstractyes

Explore more

Same venueQueen Mary Research Online (Queen Mary University of London)Same topicDark Matter and Cosmic PhenomenaFrench-language works237,207