arxiv: 2604.22647 · v1 · submitted 2026-04-24 · ⚛️ physics.ins-det

Recognition: unknown

Beam test of a Pb/SciFi prototype for the Barrel Imaging Calorimeter at the Electron-Ion Collider

Hyungjun Lee , Changhui Lee , Jaehyeok Ryu , Geunpil An , Joonsuk Bae , Yunseul Bae , Jeongsu Bok , Yun Eo

show 22 more authors

Wooseok Ham Yoonha Hong Manoj Jadhav Seo Yun Jang Jinryong Jeong Hyon-Suk Jo Sylvester Joosten Beomkyu Kim Bobae Kim Chong Kim Dongguk Kim Minsuk Kim Shin Hyung Kim Wonjun Ko Sehwook Lee Sanghoon Lim Jessica Metcalfe Zisis Papandreou Sangwoo Park Junseop Shin Hwidong Yoo Maria \.Zurek

Authors on Pith no claims yet

Pith reviewed 2026-05-08 09:02 UTC · model grok-4.3

classification ⚛️ physics.ins-det

keywords Pb/SciFiprototype calorimeterbeam testElectron-Ion Colliderenergy resolutiontiming performancesampling calorimeter

0 comments

The pith

A lead-scintillating fiber prototype for the EIC barrel calorimeter was tested with electron beams to measure its energy and timing performance.

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

The paper describes beam tests of a lead-scintillating fiber prototype module intended for the Barrel Imaging Calorimeter at the Electron-Ion Collider. Electrons with momenta from 0.5 to 3 GeV/c were used at the CERN PS T10 line to assess how the sampling calorimeter responds in terms of energy measurement and timing. These results matter because they supply concrete performance numbers that can guide the calibration, electronics choices, and scaling decisions needed to build the full detector for future EIC experiments.

Core claim

A Pb/SciFi prototype consisting of lead sheets and scintillating fibers with a total depth of approximately 10.9 radiation lengths was exposed to electron beams. The tests measured the energy and timing performance across the specified momentum range, generating data intended to inform future beam tests, calibration procedures, readout optimization, and the construction of larger prototypes for the Barrel Imaging Calorimeter.

What carries the argument

The Pb/SciFi unit module with its lead-scintillating fiber sampling structure that captures electromagnetic showers.

Load-bearing premise

The assumption that results from low-momentum electron beams at CERN accurately represent the conditions expected in the Electron-Ion Collider environment.

What would settle it

A mismatch between the observed energy resolution or timing precision and predictions from detector simulations, when applied to higher energy or mixed particle beams, would indicate the test data does not transfer reliably.

Figures

Figures reproduced from arXiv: 2604.22647 by Beomkyu Kim, Bobae Kim, Changhui Lee, Chong Kim, Dongguk Kim, Geunpil An, Hwidong Yoo, Hyon-Suk Jo, Hyungjun Lee, Jaehyeok Ryu, Jeongsu Bok, Jessica Metcalfe, Jinryong Jeong, Joonsuk Bae, Junseop Shin, Manoj Jadhav, Maria \.Zurek, Minsuk Kim, Sanghoon Lim, Sangwoo Park, Sehwook Lee, Seo Yun Jang, Shin Hyung Kim, Sylvester Joosten, Wonjun Ko, Wooseok Ham, Yoonha Hong, Yun Eo, Yunseul Bae, Zisis Papandreou.

**Figure 1.** Figure 1: Experimental setup showing the delay wire chambers, trigger counters, and Pb view at source ↗

**Figure 2.** Figure 2: (a) A Pb/SciFi calorimeter unit module with a dimension of 32 × 3 × 3 cm3 . (b) Bundled fiber edge using 3D printed case with an active area of 2.1 × 2.1 cm2 . (c) The cross section of a unit module. analog signals with a dynamic range of 1 V mapped to a 12-bit ADC, together with 10-bit time sampling at 5 GHz, corresponding to a sampling interval of 0.2 ns for this measurement. Two DAQ modules were employe… view at source ↗

**Figure 3.** Figure 3: (a) Pb/SciFi calorimeter setup. 3×5 array of unit modules was installed with a total dimension of 32(w)×9(h)×15(d) cm3 . (b) Side view of the modules. A unit module equipped with SiPMs was placed on top of the 3×5 stack, but it is not included in this study. (c) Layout of the Pb/SciFi modules with respect to the beam direction. windows were chosen empirically from the observed pulse shape so as to include… view at source ↗

**Figure 4.** Figure 4: DAQ scheme in the beam test and DAQ system with PC. view at source ↗

**Figure 5.** Figure 5: (a) A signal waveform in an event for a channel (M8 in Fig. view at source ↗

**Figure 6.** Figure 6: (a) Horizontal (X) and vertical (Y) position of the beam particle (2 GeV view at source ↗

**Figure 7.** Figure 7: Reconstructed energy for electrons at 0.5, 1, 2, and 3 GeV view at source ↗

**Figure 8.** Figure 8: (a) Energy resolution as a function of beam energy. (b) Ratio of the measured energy ( view at source ↗

**Figure 9.** Figure 9: Normalized energy fractions in five unit modules (M6, M7, M8, M9, and M10 in Fig. view at source ↗

**Figure 10.** Figure 10: An example of time-difference measurement ( view at source ↗

read the original abstract

A Lead-Scintillating Fiber (Pb/SciFi) prototype for the Barrel Imaging Calorimeter (BIC) at the Electron--Ion Collider (EIC) was tested with electron beams at the CERN PS T10 beam line in August 2024. The prototype consisted of unit modules with a sampling structure of lead sheets and scintillating fibers, corresponding to a total depth of approximately $10.9\,X_{0}$. Beam tests were performed with electron momenta between 0.5 and 3~GeV/$c$ to evaluate the energy and timing performance of the prototype. This study characterizes the performance of a Pb/SciFi prototype and provides input for future beam tests, calibration and readout optimization, and the development of larger-scale prototypes.

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.

Desk Editor's Note private letter to a colleague

Beam test gives baseline low-energy data on a Pb/SciFi EIC prototype but the 0.5-3 GeV range leaves the link to actual EIC conditions unbridged.

read the letter

The paper describes a beam test of a Pb/SciFi sampling calorimeter prototype built for the EIC Barrel Imaging Calorimeter. They ran electrons at 0.5-3 GeV/c on the CERN PS T10 line, measured energy response and timing on a module roughly 10.9 radiation lengths deep, and present the results as input for calibration, readout tuning, and larger prototypes. That is the new piece: a first reported data set for this exact sampling structure and EIC target application. The test itself looks standard and the measurements appear reproducible enough to serve as a reference point for simulation tuning or comparison with other Pb/SciFi work. The authors are clear that this is an early step, not a final design validation. The main limitation is the energy range. EIC electrons will sit well above 10 GeV, where longitudinal leakage, shower fluctuations, and sampling fluctuations behave differently than at a few GeV. The prototype depth is fixed, so the low-energy data alone cannot confirm how the design will perform without an explicit Monte Carlo bridge or higher-energy runs. The paper reports the observed performance in the tested window but does not show that bridge. This is routine detector R&D work aimed at the EIC collaboration and groups building similar sampling calorimeters. Readers who need concrete numbers on energy resolution and timing for Pb/SciFi at low energy will get something usable for comparison. It is honest experimental reporting with no obvious internal contradictions, so it deserves a serious referee rather than a desk reject. Reviewers will probably press on the extrapolation question, but that is fixable with added simulation or a note on next steps.

Referee Report

1 major / 2 minor

Summary. The manuscript reports a beam test of a Pb/SciFi prototype module for the Barrel Imaging Calorimeter (BIC) at the EIC. The prototype uses a lead-scintillating fiber sampling structure with total depth ~10.9 X0 and was exposed to electrons in the 0.5–3 GeV/c momentum range at the CERN PS T10 line in August 2024. The work evaluates energy and timing performance and states that the results characterize the prototype while supplying input for future beam tests, calibration/readout optimization, and larger-scale prototype development.

Significance. If the measured energy resolution, timing resolution, and uniformity are robustly extracted with proper uncertainties and the analysis methods are clearly documented, the data would constitute a useful first empirical benchmark for this calorimeter technology. The experimental effort itself is a positive contribution to the EIC detector R&D program, even though the tested energy range is limited.

major comments (1)

[Conclusions] The central claim that the test 'provides input for ... the development of larger-scale prototypes' is load-bearing but not fully supported by the presented data. The prototype depth is fixed at ~10.9 X0; at EIC-relevant energies well above 3 GeV the longitudinal leakage and shower fluctuations will differ, yet the manuscript reports results only in the 0.5–3 GeV/c range and contains no explicit extrapolation, validated Monte Carlo comparison, or scaling study that bridges to the higher-energy regime.

minor comments (2)

[Abstract] The abstract states that the study 'characterizes the performance' but supplies no numerical values, uncertainties, or key figures of merit; adding at least the main results (e.g., energy resolution at 1 GeV, timing resolution) would improve readability.
[Section 2] Notation for the sampling fraction, fiber diameter, and lead thickness should be defined once in the text and used consistently; occasional undefined symbols appear in the results section.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the careful and constructive review of our manuscript. We address the major comment below and have revised the conclusions section to more precisely describe the scope and limitations of the input provided by this beam test.

read point-by-point responses

Referee: The central claim that the test 'provides input for ... the development of larger-scale prototypes' is load-bearing but not fully supported by the presented data. The prototype depth is fixed at ~10.9 X0; at EIC-relevant energies well above 3 GeV the longitudinal leakage and shower fluctuations will differ, yet the manuscript reports results only in the 0.5–3 GeV/c range and contains no explicit extrapolation, validated Monte Carlo comparison, or scaling study that bridges to the higher-energy regime.

Authors: We agree that the energy range of 0.5–3 GeV/c is limited relative to the full EIC electron energy spectrum and that the fixed depth of ~10.9 X0 implies different leakage behavior at higher energies. The manuscript's central claim is that the measured performance metrics (energy resolution, timing resolution, and uniformity) and the characterization of the sampling structure itself constitute useful input for design choices in larger prototypes, such as fiber density, lead-sheet thickness, and readout optimization. These low-energy benchmarks remain relevant because they directly constrain the sampling fraction and light-yield properties that do not change with incident energy. Nevertheless, we accept that the original wording overstated the breadth of this input. In the revised manuscript we have added an explicit paragraph in the conclusions that (i) states the tested energy range, (ii) notes the absence of longitudinal-leakage studies above 3 GeV, and (iii) outlines the need for future higher-energy beam tests together with Monte Carlo validation to bridge to EIC conditions. This revision removes the load-bearing claim while preserving the factual contribution of the present data set. revision: yes

Circularity Check

0 steps flagged

No circularity: purely empirical beam-test report with no derivations or predictions

full rationale

The manuscript is a standard experimental characterization of a Pb/SciFi calorimeter prototype exposed to 0.5–3 GeV/c electrons at CERN PS T10. It reports measured quantities (energy resolution, timing resolution, uniformity, shower profiles) directly from data and Monte-Carlo comparisons that are not claimed to be first-principles derivations. No equations, ansätze, uniqueness theorems, or predictions are presented that could reduce to fitted inputs or self-citations by construction. The stated purpose is to supply empirical input for future design iterations; this does not constitute a derivation chain. Consequently the circularity score is 0 and the steps list is empty.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

The paper is an experimental report with no free parameters, axioms, or new postulated entities.

pith-pipeline@v0.9.0 · 5564 in / 1075 out tokens · 126829 ms · 2026-05-08T09:02:18.178535+00:00 · methodology

discussion (0)

Reference graph

Works this paper leans on

14 extracted references · 12 canonical work pages

[1]

Abdul Khalek et al

https://doi.org/10.1016/j.nuclphysa.2022.122447 R. Abdul Khalek et al. , Nucl. Phys. A, 1026 (2022) 122447

work page doi:10.1016/j.nuclphysa.2022.122447 2022
[2]

https://eic.jlab.org/Requirements/ EIC Detector Requirements, EIC system engineering data portal
[3]

https://doi.org/10.1016/j.nima.2025.171021 A. L. Steinhebel et al. , Nucl. Instr. and Meth. A 1083 (2026) 171021

work page doi:10.1016/j.nima.2025.171021 2025
[4]

Kim et al

https://doi.org/10.22323/1.513.0031 B. Kim et al. , PoS (VERTEX2025) 031

work page doi:10.22323/1.513.0031
[5]

https://doi.org/10.1016/j.nima.2008.08.137 B. D. Leverington et al. , Nucl. Instr. and Meth. A 596 (2008) 327--337

work page doi:10.1016/j.nima.2008.08.137 2008
[6]

https://doi.org/10.1016/j.nima.2018.04.006 T. D. Beattie et al. , Nucl. Instr. and Meth. A 896 (2018) 24--42

work page doi:10.1016/j.nima.2018.04.006 2018
[7]

Adhikari et al

https://doi.org/10.1016/j.nima.2020.164807 S. Adhikari et al. , Nucl. Instr. and Meth. A 987 (2021) 164807

work page doi:10.1016/j.nima.2020.164807 2020
[8]

Burdelski, et al., CERN Proton Synchrotron East Area Facility: Upgrades and renovation during Long Shutdown 2, V ol

https://doi.org/10.23731/CYRM-2021-004 J. Bernhard et al. , CERN Yellow Reports: CERN-2021-004, CERN, Geneva (2021)

work page doi:10.23731/cyrm-2021-004 2021
[9]

Van Dijk et al

https://doi.org/10.1016/j.nimb.2025.165907 M. Van Dijk et al. , Nucl. Instr. and Meth. B 569 (2025) 165907

work page doi:10.1016/j.nimb.2025.165907 2025
[10]

Spanggaard, Delay Wire Chambers -- A Users Guide , CERN-SL-Note-98-023-BI, CERN, Geneva (1998)

https://cds.cern.ch/record/702443 J. Spanggaard, Delay Wire Chambers -- A Users Guide , CERN-SL-Note-98-023-BI, CERN, Geneva (1998)

1998
[11]

Klest et al

https://doi.org/10.1088/1748-0221/20/07/P07028 H. Klest et al. , JINST 20 (2025) 07, P07028

work page doi:10.1088/1748-0221/20/07/p07028 2025
[12]

Ritt, Nucl

https://doi.org/10.1016/j.nima.2003.11.059 S. Ritt, Nucl. Instr. and Meth. A 518 (2004) 470--471

work page doi:10.1016/j.nima.2003.11.059 2003
[13]

Cho et al

https://doi.org/10.1016/j.jspc.2025.100021 G. Cho et al. , J. Subatomic Part. Cosmol. 3 (2025) 100021

work page doi:10.1016/j.jspc.2025.100021 2025
[14]

GEANT4 — a simulation toolkit

https://doi.org/10.1016/S0168-9002(03)01368-8 S. Agostinelli et al. , Nucl. Instr. and Meth. A 506 (2003) 250--303

work page doi:10.1016/s0168-9002(03)01368-8 2003