Slow Extraction Beam Commissioning for the Mu2e Experiment at Fermilab

A.Narayanan (1); Batavia; B.Drendel (1); D.Still (1); D.VanderMeulen (1) ((1) Fermi National Accelerator Laboratory; G.Annala (1); G.Deinlein (1); J.Berlioz (1); J.Morgan (1); J.StJohn (1)

Slow Extraction Beam Commissioning for the Mu2e Experiment at Fermilab

T0 review · 1 major / 0 minor · reviewed 2026-06-25 · grok-4.3

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Pith's one-line read Fermilab has reconfigured its Muon Campus to deliver slow-extracted 8 GeV proton beams for the Mu2e experiment after the g-2 run.

desk verdict This is a routine operational report on Mu2e beam commissioning that documents the reconfiguration but adds no new techniques or findings. read the letter →

arxiv 2606.25140 v1 pith:NHH3LJIT submitted 2026-06-23 physics.acc-ph

V. Nagaslaev (1) , G.Annala (1) , J.Berlioz (1) , G.Deinlein (1) , B.Drendel (1) , J.Morgan (1) , A.Narayanan (1) , J.StJohn (1)

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D.Still (1) D.VanderMeulen (1) ((1) Fermi National Accelerator Laboratory Batavia United States)

This is my paper

classification physics.acc-ph

keywords slowextractionbeamcommissioningMuonCampusMu2eprotonbeamsFermilab

verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper reports the shift of the Muon Campus facility from supplying 3 GeV muon beams to the g-2 storage ring to providing slow-extracted 8 GeV proton beam spills for Mu2e. Full-scale commissioning with slow extraction occurred during the 2025 run and a second campaign in early 2026. Results and the current operational status of this reconfiguration are presented.

What carries the argument

The reconfigured beam line delivering slow-extracted 8 GeV proton spills

What would settle it

Commissioning data showing that the achieved spill structure or intensity falls short of Mu2e requirements would indicate the reconfiguration is insufficient.

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Extended reading notes

Core claim

Following the successful completion of the Muon g-2 experiment run at Fermilab, the Muon Campus facility has been reconfigured from delivering 3 GeV muon beams to the g-2 storage ring to providing slow-extracted 8 GeV proton beam spills for the Mu2e experiment, with the first full-scale commissioning run conducted during the 2025 run and a second run in early 2026.

Load-bearing premise

The reconfigured beam line can deliver the intensity, spill structure, and stability required by Mu2e without fundamental redesign.

Editorial extensions

If this is right

The Muon Campus now supports slow-extracted proton operations for Mu2e.
Beam delivery can proceed without requiring a new dedicated line.
Further commissioning data will guide adjustments for stable long-term running.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

This approach demonstrates that existing accelerator infrastructure can be repurposed between muon and proton programs at the same campus.
Future experiments could benefit from similar incremental reconfigurations rather than building new beam lines from scratch.
Performance metrics from these runs provide a baseline for predicting uptime and beam quality in the Mu2e physics program.

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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Desk Editor's Note

read the letter

The punchline is that this is a standard operational status report on reconfiguring the Fermilab beamline for the Mu2e experiment, and it doesn't introduce any new physics, methods, or insights beyond documenting the work done.

The paper describes how the Muon Campus was switched from 3 GeV muon beams for g-2 to 8 GeV slow-extracted protons for Mu2e. It covers the first commissioning run in 2025 and the second in early 2026, presenting the results and current status.

What it does well is provide a clear timeline and overview of the changes made to the facility. This can be helpful for tracking the transition between experiments at the same site and for anyone needing to understand the beam parameters now in use.

The soft spots are minor but real. The work is descriptive rather than analytical, with no new technique claimed or demonstrated. If the full paper includes quantitative data on beam intensity, spill quality, or stability, that would be the useful part, but the abstract alone doesn't show enough to evaluate how successful the commissioning has been. The assumption that the existing line can handle the new requirements without major changes seems to have been tested in practice, and the paper reports on that.

This paper is mainly for the Mu2e team and Fermilab operations people. A broader audience in accelerator physics might skim it for context but won't find reusable results or methods.

I wouldn't bring this to a reading group. It is not something I would cite in my own work. It does not seem to require or benefit from peer review in a journal; a conference abstract or internal note would fit better.

Referee Report

1 major / 0 minor

Summary. The manuscript describes the reconfiguration of Fermilab's Muon Campus beamline from 3 GeV muon delivery to the g-2 storage ring to slow-extracted 8 GeV proton spills for Mu2e. It reports completion of the first full-scale commissioning run in 2025 and a second run in early 2026, and states that results and the current status of the campaign are presented.

Significance. Successful slow-extraction commissioning is a prerequisite for Mu2e data taking; a clear operational report on the beamline transition would provide useful documentation for accelerator facilities performing similar mode changes.

major comments (1)

[Abstract] Abstract: the text states that 'results and current status of this commissioning campaign' are presented, yet no quantitative beam parameters (intensity, spill duty factor, stability metrics), figures, or tables appear in the provided manuscript text. This absence prevents evaluation of whether the reconfigured line meets Mu2e requirements and is therefore load-bearing for the central descriptive claim.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the careful review and constructive feedback on the manuscript. We address the single major comment below.

read point-by-point responses

Referee: [Abstract] Abstract: the text states that 'results and current status of this commissioning campaign' are presented, yet no quantitative beam parameters (intensity, spill duty factor, stability metrics), figures, or tables appear in the provided manuscript text. This absence prevents evaluation of whether the reconfigured line meets Mu2e requirements and is therefore load-bearing for the central descriptive claim.

Authors: We agree that the current version of the manuscript does not contain the quantitative beam parameters, figures, or tables needed to substantiate the abstract's claim. In the revised manuscript we will add the relevant commissioning results, including measured intensity, spill duty factor, stability metrics, and supporting figures and tables that demonstrate performance relative to Mu2e requirements. revision: yes

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity in descriptive commissioning report

full rationale

The paper is a purely operational commissioning report describing the reconfiguration of the Muon Campus beamline and the execution of two full-scale runs. It contains no derivations, equations, fitted parameters, predictions, or load-bearing self-citations. All claims are factual descriptions of hardware changes and observed beam performance, with no internal reduction of outputs to inputs by construction.

Assumptions & free parameters 0 free parameters · 0 assumptions · 0 invented entities

This is an experimental commissioning report with no theoretical derivations, free parameters, axioms, or invented entities.

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Cite this review

Pith. "Pith review of Slow Extraction Beam Commissioning for the Mu2e Experiment at Fermilab." pith.science (2026). https://pith.science/paper/NHH3LJIT

@misc{pith2026260625140,
  author       = {Pith},
  title        = {Pith review of: Slow Extraction Beam Commissioning for the Mu2e Experiment at Fermilab},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/NHH3LJIT}},
  note         = {Machine review of arXiv:2606.25140}
}

read the original abstract

Following the successful completion of the Muon g-2 experiment run at Fermilab, the Muon Campus facility has been reconfigured from delivering 3 GeV muon beams to the g-2 storage ring to providing slow-extracted 8 GeV proton beam spills for the Mu2e experiment. The first full-scale commissioning run with slow extraction was conducted during the 2025 run, followed by the second run in early 2026. We present the results and current status of this commissioning campaign.

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Reference graph

Works this paper leans on

3 extracted references · 2 canonical work pages

[1]

The Mu2e Technical Design Report, FERMILAB-DE- SIGN-2014-01, DOI=10.2172/1172555

work page doi:10.2172/1172555 2014
[2]

The Fermilab Antiproton Source Design Report, 1982, FERMILAB-DESIGN-1982-02

1982
[3]

G-2 Technical Design Report, FERMILAB -FN-0992-E https://doi.org/10.48550/arXiv.1501.06858

work page Pith review arXiv doi:10.48550/arxiv.1501.06858

Pith tools

Reviewed June 25, 2026 · model on record in the stance chip above.

[1] [1]

The Mu2e Technical Design Report, FERMILAB-DE- SIGN-2014-01, DOI=10.2172/1172555

work page doi:10.2172/1172555 2014

[2] [2]

The Fermilab Antiproton Source Design Report, 1982, FERMILAB-DESIGN-1982-02

1982

[3] [3]

G-2 Technical Design Report, FERMILAB -FN-0992-E https://doi.org/10.48550/arXiv.1501.06858

work page Pith review arXiv doi:10.48550/arxiv.1501.06858