Reversible photochromism of synthetic hackmanites in radiation detection and quantification
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.
Bibliographic record
Abstract
The subject of this thesis is centered on a mineral called hackmanite, also known as photochromic sodalite. It is found naturally in remote, mountainous places in Afghanistan, Pakistan, Greenland, Russia, Canada, and the United States. The natural mineral is costly to extract and – depending on the location – its optical properties and chemical impurities vary arbitrarily. Thus, it is not only more predictable, but also sustainable to synthesize the mineral in a laboratory from traceable reagents that contain known amounts of impurities. The synthesis route used in the experimental section in this work is a solid-state method where the reagents are mixed and heated in an oven at 850 °C and reduced with a hydrogen‒nitrogen gas mixture. The product, hackmanite (Na8Al6Si6O24(Cl,S)2), shows properties including luminescence, persistent luminescence, and reversible photochromism upon exposure to UV, X, gamma, nuclear, or particle radiation. Hackmanite’s photochromism is of particular interest since the coloration from white to pink can be reversed with visible light or heat, and this cycle can be repeated indefinitely. Hackmanite is thus able to react to its surrounding radiation atmosphere, and what makes the property even more interesting is that upon high-energy gamma radiation exposure the material “remembers” the exposure with a change of its color centers. In UV-induced coloration, the mechanism involves an electron transfer from a disulfide anion to a nearby chloride vacancy, which is a defect in the lattice due to the requirement of charge neutrality in the crystal. However, in X-ray- or other highenergy radiation-induced coloration the incident energies are so high that the coloration is caused by core-shell electrons and subsequent holes trapping after thermalization. Due to the nature of the coloration process, hackmanite’s application region spans from the high-energy gamma radiation to UV, however the material can also be used to detect visible light since the bleaching process (electrons returning to disulfide ions from the trap) occurs in the visible wavelength region. This property can be used for taking a photograph, as is shown in this thesis. KEYWORDS: hackmanite, photochromism, radiation detection, dosimetry, photography
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Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it