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Status and Future Prospects of the NEWS-G Experiment

by P. Knights, on behalf of the NEWS-G Collaboration

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Submission summary

Authors (as registered SciPost users): Patrick Knights
Submission information
Preprint Link: scipost_202210_00039v2  (pdf)
Date accepted: 2023-04-28
Date submitted: 2022-11-25 17:26
Submitted by: Knights, Patrick
Submitted to: SciPost Physics Proceedings
Proceedings issue: 14th International Conference on Identification of Dark Matter (IDM2022)
Ontological classification
Academic field: Physics
  • Gravitation, Cosmology and Astroparticle Physics
  • High-Energy Physics - Experiment
Approach: Experimental


The NEWS-G collaboration is searching for light dark matter using spherical proportional counters. Access to the mass range from 50 MeV to 10 GeV is enabled by the combination of low energy threshold, light gaseous targets (H, He, Ne), and highly radio-pure detector construction. Several of the recent developments that have paved the way for the operation of a new 140 cm in diameter, spherical proportional counter are presented. Constructed and commissioned at LSM using 4N copper with a $500\;\si{\micro\meter}$ electroplated inner layer, the detector is now installed in SNOLAB, where it has begun data taking. Building on the electroplating of the current detector, the collaboration construct its next detector directly in the underground laboratory, using ultra-pure copper electroforming. The design and construction of ECUME, a 140 cm in diameter spherical proportional counter fully electroformed underground is discussed, along with the potential to achieve sensitivity reaching the neutrino floor in light Dark Matter searches with a next-generation detector.

Author comments upon resubmission

Dear Editors,
The authors would like to thank the reviewer for their thorough reading of the manuscript and for their helpful comments, which have improved its clarity in this resubmission. We have addressed each of their comments directly in the list of changes.
Best Regards,
Patrick Knights, on behalf of the authors.

List of changes

Changes were made in response to the reviewer's comments.

- “Access to this region of parameter space requires either novel detection channels [5] or lower energy thresholds and light targets.” Can you provide references for “lower energy thresholds and light targets”?
>>We have added a reference to the recent APPEC committee report [2] at this point.

- “This produced the most stringent constraint on the spin-independent DM-nucleon scattering cross-section, 4.4 × 10−37 cm2, for a 0.5 GeV mass DM candidate [10] ” misleading - result was published in 2017 and not anymore the most stringent. Rephrase or clarify?
>>Thank you for highlighting this, we have rephrased it to more accurately convey that it was the most stringent constraint at that time.

- “The detector has since been installed inside…” - heavy, rephrase please
>>We have rephrased this to improve clarity.

- “The next generation NEWS-G detectors will be constructed using ultra-pure copper electroforming [?] ” fix the referring

- On Fig1. Logo would be good to enlarge
>>While we do not disagree with you, this figure is a standard one that we would prefer not to change at this point.

- “The projected sensitivity of ECuME and DarkSPHERE in a DM-nucleon spin-independent cross-section versus DM mass is shown in Figure ??.” - provide correct link to the figure

- “Geant4 simulations” - provide references for Geant4

- Provide references to experiments shown at Fig3.
>>We have added the references.

- Please check Acknowledgements if they are correct.
>>Thank you for highlighting this oversight, this has now been amended.

- Fix ref 14.
>>Thank you for pointing this out. We would like this to reference the proceedings of this conference, 'Search for light WIMP recoils on methane with NEWS-G', by F. A. Vazquez de Sola Fernandez, on behalf of the NEWS-G collaboration. We hope that this can be achieved at the proofs stage.

Published as SciPost Phys. Proc. 12, 024 (2023)

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