{"id":"b3cfe1d2-2e46-4f3a-9017-d007e212451d","arxiv_id":"2603.06429","paper_version":2,"verdict":"ACCEPT","confidence":"HIGH","novelty_score":4.5,"correctness_risk":"low","formal_verification":"none","parameter_count":2,"one_line_summary":"YAG:Ce shows alpha quenching factors falling from ~0.17 to ~0.10 between 6 and 1 MeV, stable light yield to −50 °C, and usable pulse-shape discrimination between alphas and gammas.","lead":"Researchers measured how a YAG:Ce crystal converts gamma and alpha radiation into light, including how much light alphas produce relative to gammas and how the crystal behaves when cooled. The data help design detectors that must identify particle types and stay stable in harsh or cold environments.","discovery_kind":"extension","skeptic_critique":{"model":"grok-4.5","headline":"No significant objection identified","rationale":"The reader’s weakest-assumption identification is accurate and is the only plausible soft spot in an otherwise careful experimental paper. Because the authors already note the possible non-linearity below ~100 keV and deliberately avoid the 59.5 keV line for calibration, and because the multi-gas, multi-distance data sets overlie one another, the residual risk is low. A single multi-line γ calibration run would close the loop; until then the published QF values and PSD figures remain usable. No stronger load-bearing concern appears, so the ACCEPT verdict and high-confidence assessment stand.","tokens_in":8441,"tokens_out":491,"duration_ms":5124,"concrete_test":"Acquire one additional calibration spectrum with a multi-line γ source (e.g., 137Cs 662 keV + 60Co 1.17/1.33 MeV) under identical geometry and SiPM bias; recompute the QF curve using a linear fit that includes these higher-energy points. If any QF value shifts by more than the existing error bars (~0.01), the linearity assumption would require revision; otherwise the published curve stands.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The paper’s central claims (energy-dependent QF from ~0.17 to ~0.10 between 5.49 and ~1 MeV, temperature evolution of τ_long, and partial-charge PSD separations of ~2.3σ / ~1.3σ) rest on standard, well-documented experimental procedures. The reader correctly flags the assumption that β/γ light yield is linear above ~100 keV and is therefore fixed solely by the 511 keV 22Na peak. That assumption is conventional for inorganic scintillators in this energy window, is explicitly acknowledged by the authors (Sec. II B), and is cross-checked by multiple gas/distance configurations that all collapse onto a single QF curve. No internal inconsistency, circular calibration, or unaccounted systematic that would reverse the reported trends is evident. The work is incremental characterization rather than a foundational claim, so residual calibration uncertainty does not undermine the reported numbers at the level needed to change the verdict.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.5","summary":"The manuscript reports a laboratory characterization of a 10\times10\times10 mm^{3} YAG:Ce crystal read out by a Hamamatsu S13360 SiPM. Using a double-exponential reconstruction of physics pulses from single-cell templates, the authors extract short and long scintillation time constants (~63–67 ns and ~245–273 ns) and a light yield of ~19 000 photons MeV⁻¹. By varying gas pressure, gas species (air, Ar, He) and source–crystal distance they map the α quenching factor from ~0.17 at 5.49 MeV down to ~0.10 near 1 MeV. Temperature scans from room temperature to –50 °C show that τ_long roughly doubles while light output remains stable. Finally, a partial-charge pulse-shape parameter separates full-energy α events from 511 keV γ events at ~2.3 σ (~1.3 σ when amplitudes are matched).","tokens_in":8678,"tokens_out":984,"duration_ms":8413,"significance":"The work supplies a self-consistent, multi-configuration data set for a commercially available YAG:Ce crystal that is already used in beam diagnostics, space instrumentation and low-background applications. The energy-dependent QF curve, the temperature evolution of the slow component, and the quantitative PSD figures of merit are directly usable for detector design and Monte-Carlo modeling. Strengths include the explicit cross-check of QF with three gases and two geometries, the transparent single-cell reconstruction method (Fig. 1), and the clear statement of the linearity assumption used for the β/γ calibration. The results are incremental rather than foundational, yet they fill a practical gap in the literature for this material.","major_comments":[{"comment":"Sec. II B and Fig. 2: the entire QF curve is scaled by the light yield fixed solely from the 511 keV ²²Na peak under the assumption of energy-independent β/γ response above ~100 keV. While this is conventional and acknowledged by the authors, a single-point calibration leaves an overall systematic that is not quantified. A brief cross-check with an additional γ line (e.g., 1.27 MeV ²²Na or an external ¹³⁷Cs source) or a short discussion of the expected non-linearity from literature would strengthen the absolute scale of the reported QF values.","section":null},{"comment":"Sec. III: the PSD performance is quoted as ~2.3 σ (full-energy α) and ~1.3 σ (amplitude-matched). The text does not specify how σ is computed (Gaussian fit, RMS of the partial-charge distributions, or clustering purity). Clarifying the definition and, if possible, providing the figure-of-merit (e.g., FoM = |μ_α – μ_γ| / (σ_α + σ_γ)) would make the discrimination claim fully reproducible.","section":null}],"minor_comments":[{"comment":"Table I: the fractional short-component weight F_short is listed as 0.10 (α) and 0.15 (γ); a short sentence on how these fractions were obtained (free fit or constrained) would help readers reproduce the reconstruction.","section":null},{"comment":"Fig. 3: the vertical axis is labeled “Norm. τ_long(T)” but the caption and text state that τ_long increases by a factor of two; confirming whether the plotted quantity is τ_long(T)/τ_long(RT) or the inverse would remove ambiguity.","section":null},{"comment":"Introduction and Sec. II A: the light-yield value of ~19 000 photons MeV⁻¹ is lower than some recent literature reports (up to 3.5×10⁴). A brief remark on crystal quality, Ce concentration or light-collection geometry would place the number in context.","section":null},{"comment":"Throughout: the abstract and body use both “YAG:Ce” and “\\YAG”; consistent notation would improve readability.","section":null},{"comment":"References: Ref. [10] is cited for the reconstruction method and experimental setup; ensuring that the arXiv or journal version is publicly available at the time of publication would aid reproducibility.","section":null}],"recommendation":"minor_revision","confidential_remarks":"The manuscript is a solid, incremental characterization paper well suited to a instrumentation-focused journal. The two major points are easily addressable and do not threaten the central claims. I see no reason for rejection or major revision."},"author_rebuttal":null,"desk_editor":{"model":"grok-4.5","letter":"The useful new pieces are the continuous α quenching-factor curve from ~5.5 MeV down to ~1 MeV (0.17 → 0.10), the factor-of-two lengthening of τ_long between room temperature and −50 °C, and the partial-charge PSD separations (~2.3 σ full-energy, ~1.3 σ amplitude-matched). Prior work already had light yields, two-component decays, and qualitative PSD; this paper fills the energy- and temperature-dependent gaps with data that are immediately usable for calibration.\n\nThey did the experiment carefully. Multiple gases (air/Ar/He) and two source distances collapse onto one QF curve; ±1 mm distance systematics and calibration uncertainties are shown; single-cell template reconstruction matches the measured waveforms well (Fig. 1). Light yield ~19 000 ph/MeV and the ~70/250 ns components sit comfortably inside the literature range. The double-exponential model is standard phenomenology, not circular. No invented entities, no load-bearing free parameters that reappear as predictions.\n\nSoft spots are minor and mostly acknowledged. β/γ light yield is fixed from the 511 keV peak alone (linearity assumed above ~100 keV); that is conventional and they say so, but any non-linearity would rescale the whole QF curve. They drop a possible ~1 µs component for fit stability. PSD is weaker than for GAGG:Ce because of lower light yield and dark counts. None of this reverses the reported trends.\n\nThis is for people already using or considering YAG:Ce who need numbers for energy reconstruction, temperature corrections, or particle ID. It is incremental characterization, not a new detection channel, but the data are new, cross-checked, and cleanly presented. I would send it to referees without hesitation; a serious editor should too. Worth citing if you work with this crystal or similar inorganic scintillators.","headline":"Solid, usable characterization of commercial YAG:Ce: continuous α QF curve 1–6 MeV, τ_long temperature dependence, and quantitative PSD numbers that groups can actually cite.","tokens_in":9279,"tokens_out":545,"would_cite":true,"duration_ms":5326,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":["29.40.Mc","07.85.Fv"],"model":"grok-4.5","headline":"YAG:Ce alpha quenching falls from 0.17 to 0.10 between 5.5 and 1 MeV, while pulse shape still separates alphas from gammas.","keywords":["YAG:Ce","scintillator characterization","light yield","alpha quenching factor","pulse-shape discrimination","SiPM readout","temperature dependence"],"falsifier":"Repeat the pressure-scanned alpha measurements with an independent electron-beam or Compton-edge calibration that covers the same 1–6 MeV window and check whether the extracted quenching factors remain inside the reported 0.10–0.17 band.","tokens_in":9389,"feed_emoji":"⚛️","tokens_out":963,"duration_ms":8906,"temperature":0.7,"pith_summary":"The paper measures how a commercial YAG:Ce crystal converts energy into light when hit by gamma rays and alpha particles, and how that light pulse changes with particle type and temperature. It reports a light yield near 19 000 photons per MeV for gammas, a two-component decay of roughly 65 ns and 250 ns, and an alpha quenching factor that drops from about 0.17 at 5.5 MeV to 0.10 near 1 MeV. Cooling from room temperature to -50 °C roughly doubles the long decay constant while leaving light output essentially unchanged. Using a simple partial-charge cut on the waveform, the same crystal can still tag full-energy alphas versus 511 keV gammas at roughly 2.3 standard deviations. Together these numbers give a practical map of when YAG:Ce can be used for energy spectroscopy and particle identification under ordinary laboratory and outdoor conditions.","feed_headline":"Alpha quenching in YAG:Ce drops to 0.10 near 1 MeV","feed_subtitle":"Pulse shape still tags alphas from gammas while light yield holds from room temperature to -50 °C","key_machinery":"Reconstruction of measured waveforms as random sums of single-SiPM-cell pulses drawn from a double-exponential emission law, which simultaneously yields the short and long decay constants, their relative weights, and the absolute number of detected photons used for light-yield and quenching calculations.","core_discovery":"For a 1 cm YAG:Ce cube read out by a SiPM, the alpha quenching factor decreases smoothly from approximately 0.17 to 0.10 as the energy deposited by alphas falls from 5.49 MeV to about 1 MeV, while a single partial-charge pulse-shape parameter separates those alphas from equal-amplitude gammas at the 1–2 σ level and full-energy alphas from 511 keV gammas at about 2.3 σ.","pith_inferences":["Because quenching continues to fall toward 1 MeV, applications that rely on low-energy alphas (e.g., surface contamination monitors) will need an explicit energy-dependent quenching model rather than a single constant.","The observed temperature-independent light yield combined with a slowing decay suggests that YAG:Ce may remain competitive for outdoor or space instruments where power budgets forbid active cooling of the crystal itself.","If the partial-charge separation scales with photon statistics, higher-light-yield YAG:Ce variants already reported in the literature should push the discrimination figure of merit well above 3 σ at the same energies."],"forward_implications":["Energy reconstruction for alphas in YAG:Ce must apply an energy-dependent correction that reaches a factor of ten near 1 MeV.","Particle identification remains usable down to amplitudes matching the 511 keV gamma peak, albeit with reduced separation power.","Cooling to -50 °C lengthens the slow component by a factor of two without spoiling light yield, so timing cuts must be retuned with temperature.","The same vacuum-chamber method can be extended below 1 MeV by thinning the crystal to suppress the competing 60 keV gamma line."],"fun_headline_variants":["YAG:Ce alpha quench falls from 0.17 to 0.10 near 1 MeV","Alpha quenching in YAG:Ce declines smoothly to 0.10","YAG:Ce alphas quench to 0.10 while PSD tags them from gammas","Quench factor drops to 0.10 for low-energy alphas in YAG:Ce","YAG:Ce alpha quench falls with energy; light yield holds to -50 °C"],"cache_read_input_tokens":128,"weakest_assumption_plain":"The light yield for electrons and gammas is taken as constant above roughly 100 keV and is therefore fixed solely by the 511 keV peak; any real non-linearity in that range would stretch or compress the entire quenching-factor curve.","fun_headline_variants_meta":{"raw":{"variants":["YAG:Ce alpha quench falls from 0.17 to 0.10 near 1 MeV","Alpha quenching in YAG:Ce declines smoothly to 0.10","YAG:Ce alphas quench to 0.10 while PSD tags them from gammas","Quench factor drops to 0.10 for low-energy alphas in YAG:Ce","YAG:Ce alpha quench falls with energy; light yield holds to -50 °C"]},"model":"grok-4.5","effort":"low","cost_usd":0.00382,"raw_usage":{"total_tokens":1218,"prompt_tokens":824,"num_sources_used":0,"completion_tokens":116,"cost_in_usd_ticks":38200000,"prompt_tokens_details":{"text_tokens":824,"audio_tokens":0,"image_tokens":0,"cached_tokens":128},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":278,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":824,"tokens_out":116,"duration_ms":2794,"temperature":1.0,"reasoning_tokens":278,"cache_read_input_tokens":128,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-15T13:50:14.080039+00:00","model_set":{"reader":"grok-4.5"},"falsifier":"Repeat the pressure-scanned alpha measurements with an independent electron-beam or Compton-edge calibration that covers the same 1–6 MeV window and check whether the extracted quenching factors remain inside the reported 0.10–0.17 band.","supporting_citations":[],"review_version":1}