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arxiv: 2606.08664 · v1 · pith:YOAOAHL4new · submitted 2026-06-07 · ⚛️ physics.ins-det · hep-ex

Investigation of Thick-GEM detectors fabricated in India for muography application

Saikat Ghosh , Promita Roy , Subhendu Das , Shubhabrata Dutta , Nilanjan Biswas , Supratik Mukhopadhyay , Nayana Majumdar This is my paper

Pith reviewed 2026-06-27 17:40 UTC · model grok-4.3

classification ⚛️ physics.ins-det hep-ex
keywords Thick-GEMmuographymuon detectiondetection efficiencyspatial resolutiondetector fabricationcosmic muonsGEM technology
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0 comments X

The pith

Locally fabricated Thick-GEM detectors reach 99.5% muon detection efficiency and 30 μm spatial resolution for muography use.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper tests Thick-GEM detectors produced by an Indian manufacturer as possible tracking elements in a small muography prototype that images objects via muon scattering. After basic conditioning, the team measures gain curves, detection efficiency across voltages, and position resolution with a collimated source in both single-layer and double-layer setups. The detectors reach a peak efficiency of 99.5 percent and a best resolution of 30 micrometers. A reader would care if these numbers hold because they suggest that robust, locally made detectors could replace imported components in practical muon tomography systems.

Core claim

Thick-GEM detectors of size 40 mm by 48 mm, manufactured locally with variations in design parameters, exhibit gain behavior that defines usable voltage ranges in single and double-stage operation; muon detection efficiency reaches a maximum of 99.5 percent across the full operating range in both configurations; and spatial resolution measured with a collimated Fe55 source reaches 30 micrometers for both single and double-stage operation.

What carries the argument

The Thick-GEM detector, a mechanically scaled-up version of standard GEM technology that provides robustness and position resolution for tracking cosmic muons.

If this is right

  • Both single-stage and double-stage configurations deliver the same peak efficiency and resolution, allowing simpler single-layer designs to be used.
  • Gain studies identify clear voltage windows that keep the detectors in their optimal operating region.
  • The measured performance supports integration into a prototype system that identifies materials by muon multiple scattering.
  • Local production of these detectors can supply the tracking planes needed for small-scale muography setups.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If long-term aging or rate tests later confirm stability, the cost and supply advantages of domestic fabrication could accelerate deployment of muography systems in resource-limited settings.
  • The 30 micrometer resolution is measured with an X-ray source; direct comparison in a cosmic-muon beam would be needed to verify the same figure under actual operating conditions.
  • The work leaves open whether the same local fabrication process can scale to the larger areas required for full-size muography imagers of buildings or geological targets.

Load-bearing premise

Short-term gain and efficiency measurements after initial conditioning are enough to confirm that the detectors will remain stable and suitable during continuous long-term muography operation.

What would settle it

A drop in efficiency below 99 percent or worsening of spatial resolution beyond 30 micrometers after weeks of continuous operation or in a real cosmic-muon beam would falsify the claim of suitability.

read the original abstract

Muography, commonly known as muon tomography, is a passive, non-destructive imaging technique that utilizes naturally occurring cosmic-ray muons to visualize the internal density structures of large, static, or inaccessible objects. In course of developing a small prototype muography system for material identification that relies upon the multiple Coulomb scattering of muons in matter, we explored the possible use of Thick-GEM detector as muon tracking device. It is a 5-20 fold scaled-up version of traditional GEM technology, that has become increasingly popular in recent years, owing to its mechanical robustness, cost-effective production, and excellent position sensing capabilities. A few prototypes of this detector of dimension $40\,\mathrm{mm} \times 48\,\mathrm{mm}$ with variation in other design parameters, were manufactured from a local industry. Subsequent to conditioning, detailed characterization of the detectors was performed to validate their suitability in muography applications. To identify the optimal operating region, gain variation was studied under various voltage configurations for both single and double-stage configurations. Experimental measurement of muon detection efficiency across the entire operating range yielded a maximum efficiency of 99.5\% in both cases. Using a collimated Fe$^{55}$-source, the best spatial resolution was determined to be 30 $\mu$m for both single and double-stage operation.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 2 minor

Summary. The paper reports fabrication of 40 mm × 48 mm Thick-GEM prototypes in India and their post-conditioning characterization for a muography prototype based on muon multiple Coulomb scattering. Gain curves are presented for single- and double-stage operation; muon detection efficiency is measured across the operating range with a maximum of 99.5 %; spatial resolution is extracted from collimated Fe55 data yielding 30 μm in both configurations.

Significance. Demonstration of locally produced Thick-GEMs reaching high efficiency and sub-100 μm resolution would support cost-effective scaling of muography systems if long-term performance is confirmed. The direct experimental measurements constitute a concrete strength.

major comments (1)
  1. [Characterization results (efficiency and resolution paragraphs)] The central suitability claim for continuous muography operation rests on short-term post-conditioning data only. No time-dependent gain monitoring, integrated-charge aging tests, or rate-capability scans at the ~1 Hz/cm² fluxes relevant to muography are reported, leaving the persistence of the 99.5 % efficiency and 30 μm resolution unverified.
minor comments (2)
  1. [Abstract and results sections] Error bars, data-selection cuts, and full experimental-setup details (gas mixture, readout electronics, trigger logic) are absent from the efficiency and resolution measurements.
  2. [Discussion] No direct comparison to commercial Thick-GEMs is provided to benchmark the Indian-fabricated devices.

Simulated Author's Rebuttal

1 responses · 1 unresolved

We thank the referee for the constructive feedback. We address the major comment below.

read point-by-point responses

  1. Referee: [Characterization results (efficiency and resolution paragraphs)] The central suitability claim for continuous muography operation rests on short-term post-conditioning data only. No time-dependent gain monitoring, integrated-charge aging tests, or rate-capability scans at the ~1 Hz/cm² fluxes relevant to muography are reported, leaving the persistence of the 99.5 % efficiency and 30 μm resolution unverified.

    Authors: We agree that the presented data consist of short-term post-conditioning measurements and that long-term stability under continuous operation has not been demonstrated. The manuscript reports the successful local fabrication of Thick-GEM prototypes together with their initial gain, efficiency, and spatial-resolution performance; these results establish that the detectors meet the basic requirements for a muography tracking layer. We acknowledge that persistence of the 99.5 % efficiency and 30 μm resolution at the low fluxes typical of muography requires additional aging and rate-capability studies, which lie beyond the scope of the current work. We will revise the text to state explicitly that the reported figures are from initial characterization and to qualify the suitability claim accordingly. revision: partial

standing simulated objections not resolved
  • Time-dependent gain monitoring, integrated-charge aging tests, and rate-capability scans at ~1 Hz/cm² fluxes have not been performed and cannot be supplied in the present revision.

Circularity Check

0 steps flagged

No circularity: purely experimental measurements

full rationale

The paper describes fabrication of Thick-GEM prototypes, post-conditioning gain measurements under voltage configurations, muon detection efficiency scans (max 99.5%), and Fe55-based spatial resolution tests (30 μm) in single- and double-stage modes. No derivations, equations, fitted parameters, or predictions appear in the abstract or described full text. No self-citations are invoked as load-bearing premises. All reported results are direct experimental outputs, rendering the work self-contained with no reduction of claims to their own inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on standard assumptions of gaseous detector physics and the validity of short-term lab measurements as proxies for operational suitability. No free parameters are fitted to produce the headline numbers, and no new entities are postulated.

axioms (1)
  • domain assumption Standard assumptions about gas mixture behavior, voltage stability, and muon interaction in matter hold for the tested configurations.
    Invoked implicitly when interpreting gain curves and efficiency measurements as representative of detector performance.

pith-pipeline@v0.9.1-grok · 5789 in / 1292 out tokens · 18440 ms · 2026-06-27T17:40:44.132800+00:00 · methodology

discussion (0)

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Reference graph

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