papers

Publications (32)

physics.ins-det2026

Hydrofluoric acid-free titanium etching for rare-event searches

P. Knights, I. Manthos, K. Nikolopoulos +3

Rare-event search experiments require construction materials with high radiopurity to minimise background contributions. Thanks to its high mechanical strength, low density, machin…

hep-ex2025

Search for Light Dark Matter with NEWS-G at the Laboratoire Souterrain de Modane Using a Methane Target

M. M. Arora, L. Balogh, C. Beaufort +40

The NEWS-G direct detection experiment uses spherical proportional counters to search for light dark matter candidates. New results from a 10 day physics run with a $135\,\mathrm{c…

physics.ins-det2022

Purification Efficiency and Radon Emanation of Gas Purifiers used with Pure and Binary Gas Mixtures for Gaseous Dark Matter Detectors

K., Altenmüller, J. F. Castel +22

Rare event searches require extreme radiopurity in all detector components. This includes the active medium, which in the case of gaseous detectors, is the operating gas. The gases…

physics.ins-det2019

Precision laser-based measurements of the single electron response of SPCs for the NEWS-G light dark matter search experiment

G Collaboration, Q. Arnaud, J. -P. Bard +36

Spherical Proportional Counters (SPCs) are a novel gaseous detector technology employed by the NEWS-G low-mass dark matter search experiment for their high sensitivity to single el…

physics.ins-det2025

Titanium for rare-event searches: Hydrofluoric acid-free etching

P. Knights, K. Nikolopoulos, G. Rogers +2

Rare-event search experiments require construction materials with high radiopurity to minimise background contributions. Thanks to its high mechanical strength, low density, machin…

physics.ins-det2022

ACHINOS: A Multi-Anode Read-Out for Position Reconstruction and Tracking with Spherical Proportional Counters

I. Katsioulas, P. Knights, I. Manthos +4

The spherical proportional counter is a versatile gaseous detector with physics applications ranging from rare event searches to fast neutron spectroscopy. In its simplest form, th…

physics.ins-det2021

Quenching factor measurements of neon nuclei in neon gas

L. Balogh, C. Beaufort, A. Brossard +47

The NEWS-G collaboration uses Spherical Proportional Counters (SPCs) to search for weakly interacting massive particles (WIMPs). In this paper, we report the first measurements of…

hep-ex2025

Transforming a rare event search into a not-so-rare event search in real-time with deep learning-based object detection

J. Schueler, H. M. Araújo, S. N. Balashov +40

Deep learning-based object detection algorithms enable the simultaneous classification and localization of any number of objects in image data. Many of these algorithms are capable…

hep-ex2022

Solar Kaluza-Klein axion search with NEWS-G

G collaboration, Q. Arnaud, L. Balogh +39

Kaluza-Klein (KK) axions appear in theories with extra dimensions as higher mass, significantly shorter lifetime, excitations of the Peccei-Quinn axion. When produced in the Sun, t…

physics.ins-det2025

Design of high-strength, radiopure, electroformed copper-based alloys for rare-event searches: Impact of layer configuration on heat treatments

D. Spathara, P. Knights, K. Nikolopoulos

State-of-the-art and next-generation rare-event search experiments rely on detector materials with stringent requirements on radiopurity and mechanical performance. Additive-free e…

hep-ex2026

Overlap-aware segmentation for topological reconstruction of obscured objects

J. Schueler, H. M. Araújo, S. N. Balashov +30

The separation of overlapping objects presents a significant challenge in scientific imaging. While deep learning segmentation-regression algorithms can predict pixel-wise intensit…

physics.ins-det2024

Measurement of scintillation from proportional electron multiplication in liquid xenon using a needle

P. Knights, H. Sekiya, I. Katsioulas +3

Charge amplification in liquids could provide single-phase xenon time projection chambers with background discrimination and fiducialisation capabilities similar to those found in…

physics.ins-det2020

Development of a Simulation Framework for Spherical Proportional Counters

I. Katsioulas, P. Knights, J. Matthews +4

The spherical proportional counter is a novel gaseous detector with numerous applications, including direct dark matter searches and neutron spectroscopy. The strengths of the Gean…

physics.ins-det2024

First operation of an ACHINOS-equipped Spherical Proportional Counter with individual anode read-out

D. Herd, I. Katsioulas, P. Knights +6

The multi-anode sensor ACHINOS revolutionised the capabilities of the spherical proportional counter by enabling large-size, high-pressure, operation and TPC-like reconstruction ca…

physics.ed-ph2018

Studying the effect of Polarisation in Compton scattering in the undergraduate laboratory

P. Knights, F. Ryburn, G. Tungate +1

An experiment for the advanced undergraduate laboratory allowing students to directly observe the effect of photon polarisation on Compton scattering is described. An initially unp…

physics.ins-det2022

Measurements of the ionization efficiency of protons in methane

G Collaboration, L. Balogh, C. Beaufort +40

The amount of energy released by a nuclear recoil ionizing the atoms of the active volume of detection appears "quenched" compared to an electron of the same kinetic energy. This d…

physics.ins-det2022

Simultaneous scintillation light and charge readout of a pure argon filled Spherical Proportional Counter

R. Bouet, J. Busto, V. Cecchini +20

The possible use of a Spherical Proportional Counter for the search of neutrinoless double beta decay is investigated in the R2D2 R&D project. Dual charge and scintillation light r…

hep-ph2022

Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications

M. Abdullah, H. Abele, D. Akimov +272

Coherent elastic neutrino-nucleus scattering (CENS) is a process in which neutrinos scatter on a nucleus which acts as a single particle. Though the total cross section is larg…

physics.ins-det2021

R2D2 spherical TPC: first energy resolution results

R. Bouet, J. Busto, V. Cecchini +20

Spherical time projection chambers (TPC), also known as spherical proportional counters, are employed in the search for rare phenomena, such as light Dark Matter candidates. The sp…

physics.ins-det2021

Neutron spectroscopy with N-filled high-pressure large-volume spherical proportional counters

I. Giomataris, S. Green, I. Katsioulas +9

Precise in-situ measurements of the neutron flux in underground laboratories is crucial for direct dark matter searches, as neutron induced backgrounds can mimic the typical dark m…

astro-ph.IM2022

EXCESS workshop: Descriptions of rising low-energy spectra

P. Adari, A. Aguilar-Arevalo, D. Amidei +303

Many low-threshold experiments observe sharply rising event rates of yet unknown origins below a few hundred eV, and larger than expected from known backgrounds. Due to the signifi…

physics.ins-det2019

Experimental Determination of Proton Hardness Factors at Several Irradiation Facilities

P. Allport, F. Bogelspacher, K. Bruce +13

The scheduled High Luminosity upgrade of the CERN Large Hadron Collider presents new challenges in terms of radiation hardness. As a consequence, campaigns to qualify the radiation…

physics.ins-det2023

Neutron spectroscopy with a high-pressure nitrogen-filled spherical proportional counter

I. Giomataris, S. Green, I. Katsioulas +8

The spherical proportional counter is a large volume gaseous detector which finds application in several fields, including direct Dark Matter searches. When the detector is filled…

physics.ins-det2025

The ionization yield in a methane-filled spherical proportional counter

M. M. Arora, L. Balogh, C. Beaufort +40

Spherical proportional counters (SPCs) are gaseous particle detectors sensitive to single ionization electrons in their target media, with large detector volumes and low background…

hep-ex2023

Exploring light dark matter with the DarkSPHERE spherical proportional counter electroformed underground at the Boulby Underground Laboratory

L. Balogh, C. Beaufort, M. Chapellier +37

We present the conceptual design and the physics potential of DarkSPHERE, a proposed 3 m in diameter spherical proportional counter electroformed underground at the Boulby Undergro…

physics.ins-det2020

A resistive ACHINOS multi-anode structure with DLC coating for spherical proportional counters

I. Giomataris, M. Gros, I. Katsioulas +9

The spherical proportional counter is a gaseous detector used in a variety of applications, including direct dark matter and neutrino-less double beta decay searches. The ACHINOS m…

physics.ins-det2023

The NEWS-G detector at SNOLAB

L. Balogh, C. Beaufort, A. Brossard +38

The New Experiments With Spheres-Gas (NEWS-G) collaboration intends to achieve Weakly Interacting Massive Particles (WIMPs) detection using Spherical Propo…

hep-ex2022

Fast Neutron Spectroscopy with a High-pressure Nitrogen-filled Large Volume Spherical Proportional Counter

I. Giomataris, I. Katsioulas, P. Knights +7

We present a fast neutron spectroscopy system based on a nitrogen-filled, large volume gaseous detector, the Spherical Proportional Counter. The system has been successfully operat…

physics.ins-det2018

A sparkless resistive glass correction electrode for the spherical proportional counter

I. Katsioulas, I. Giomataris, P. Knights +4

A new anode support structure for the spherical proportional counter is presented that incorporates a resistive correction electrode made of glass. This electrode improves the elec…

hep-ex2023

Performance of a spherical high pressure gas TPC for neutrino magnetic moment measurement

R. Bouet, J. Busto, V. Cecchini +20

The measurement of neutrino magnetic moment larger than would be a clear signature of physics beyond the standard model other than the existence of massive Dirac neu…

physics.ins-det2020

Copper electroplating for background suppression in the NEWS-G experiment

G Collaboration, L. Balogh, C. Beaufort +47

New Experiments with Spheres-Gas (NEWS-G) is a dark matter direct detection experiment that will operate at SNOLAB (Canada). Similar to other rare-event searches, the materials use…

physics.ins-det2022

Neutron spectroscopy: The case of the spherical proportional counter

I. Giomataris, I. Katsioulas, P. Knights +5

Neutron spectroscopy is an invaluable tool for many scientific and industrial applications, including underground Dark Matter searches. Neutron-induced backgrounds produced by cosm…