IceCube-Gen2 Surface Array

• IceCube-Gen2 Surface Array is a hybrid air-shower detector that combines plastic scintillators and SKALA radio antennas to measure cosmic rays and veto atmospheric backgrounds.
• Its stable station design features eight scintillator panels and three antennas per unit, integrated with precision DAQ and sub-10 ns timing calibration for accurate event reconstruction.
• Simulations and prototype studies forecast a 30-fold increase in aperture over IceTop, enabling enhanced composition analysis and anisotropy measurements from PeV to EeV energies.

Searching arXiv for relevant IceCube-Gen2 Surface Array papers to ground the article in the cited literature. arXiv search query: "IceCube-Gen2 surface array prototype station Pierre Auger Observatory scintillator radio SKALA" The IceCube-Gen2 Surface Array is the planned surface air-shower detector of the IceCube-Gen2 observatory at the South Pole. In the published design studies it is a hybrid array of plastic-scintillation detectors and radio antennas, deployed above the enlarged in-ice optical array so that the charged-particle signal at the surface, the radio emission of the electromagnetic shower component, and the high-energy muon bundle in the ice can be measured in coincidence. Its stated roles are twofold: to extend cosmic-ray measurements from the PeV region toward EeV energies, including composition-sensitive and anisotropy-sensitive observables, and to act as an active veto against downward-going atmospheric backgrounds in neutrino analyses (Clark, 2021, Ishihara, 2023, Schröder, 2023, Schroeder, 27 Feb 2025).

1. Scientific role within the IceCube-Gen2 observatory

The surface array is described in the literature as an integral component of IceCube-Gen2 rather than a peripheral add-on. Its physics program combines cosmic-ray air-shower reconstruction with detector-support functions for neutrino astronomy. In the design papers, the array measures the electromagnetic component and low-energy muons at the surface, while the deep optical array measures TeV muons or muon bundles in the ice. This coincidence geometry is repeatedly identified as the basis for composition studies, tests of hadronic-interaction models, and vetoing of atmospheric backgrounds (Schroeder, 2021, Coleman, 2023, Schroeder, 27 Feb 2025).

The quoted energy domain depends on the study and on which subsystem is emphasized. Published descriptions include “roughly $10^{15}\,\mathrm{eV}$ up to a few $\times 10^{17}\,\mathrm{eV}$” for Gen2-Surface as a veto and cosmic-ray instrument, “from $\simeq 0.5\,\mathrm{PeV}$ up to EeV” for the combined surface detector, and “several 100 TeV to a few EeV” for the full surface coverage with scintillators and radio antennas (Clark, 2021, Schröder, 2023, Coleman, 2023). This range reflects the fact that scintillators set the low threshold, whereas radio provides higher-precision observables in the transition region.

The science objectives stated across the papers are consistent in scope. They include measurements of the cosmic-ray spectrum and mass composition through and above the knee; studies of the Galactic-to-extragalactic transition; searches for PeV photons; anisotropy measurements with substantially larger statistics than IceTop; and neutrino-veto operation for the southern sky (Hou, 2023, Schröder, 8 Jul 2025, Clark, 2021). Several sources also emphasize prompt-muon and prompt-neutrino related air-shower physics as a specific opportunity opened by the enlarged surface–deep coincidence aperture (Schröder, 2023, Schroeder, 27 Feb 2025).

2. Evolving baseline design and station architecture

Across the published record, the station concept is remarkably stable even though the quoted array size changes with design stage. Each station is described as a hybrid unit with eight scintillator panels and three radio antennas, with a local field hub or TAXI DAQ for common timing, triggering, and readout (Oehler et al., 2021, Schröder, 2023, Lohan, 17 Mar 2025). The principal design evolution concerns total station count, footprint, and spacing.

Source	Quoted array scale	Quoted spacing
(Clark, 2021)	120 stations covering roughly $8\,\mathrm{km}^2$	$240\,\mathrm{m}$
(Lohan, 17 Mar 2025)	130 scintillator stations, approximate footprint $O(10\,\mathrm{km}^2)$	$240\,\mathrm{m}$
(Ishihara, 2023)	of order 150 identical stations over some $8\,\mathrm{km}^2$	approximately $240\,\mathrm{m}$ triangular grid
(Schröder, 2023)	$\simeq 160$ hybrid stations	over most of the footprint $\times 10^{17}\,\mathrm{eV}$0
(Schroeder, 2021)	162 stations, $\times 10^{17}\,\mathrm{eV}$1	$\times 10^{17}\,\mathrm{eV}$2

These differences are explicit in the sources and should not be collapsed into a single “final” number. Some papers count only the new Gen2 optical strings, others include bridging stations toward the IceTop enhancement, and some quote geometric footprint while others quote contained area or coincident aperture. This suggests that the baseline has been iteratively re-optimized as the deep-array geometry and the surface–IceTop interface matured (Clark, 2021, Schröder, 2023, Schroeder, 27 Feb 2025).

The scintillator hardware is consistently specified as plastic scintillator with wavelength-shifting-fiber readout into SiPMs. Panel area is quoted as $\times 10^{17}\,\mathrm{eV}$3 in several sources, while some later summaries describe panel pairs with effective area of order $\times 10^{17}\,\mathrm{eV}$4–$\times 10^{17}\,\mathrm{eV}$5 (Oehler et al., 2021, Schroeder, 2021, Schröder, 8 Jul 2025). Dynamic-range statements also vary by design stage: “$\times 10^{17}\,\mathrm{eV}$6 to $\times 10^{17}\,\mathrm{eV}$7 minimum-ionizing particles per panel,” “$\times 10^{17}\,\mathrm{eV}$8 decades,” and “single MIP to $\times 10^{17}\,\mathrm{eV}$9 MIPs” all appear in the literature (Ishihara, 2023, Schroeder, 2021, Coleman, 2023).

The radio subsystem is centered on SKALA-family log-periodic antennas, especially SKALA v2 or SKALA-v2, with three dual-polarized antennas per station (Verpoest, 2024, Verpoest et al., 11 Jul 2025, Schröder, 2023). The quoted band depends on whether the paper refers to the antenna hardware, the analog passband, or the analysis band. Reported values include $\simeq 0.5\,\mathrm{PeV}$0–$\simeq 0.5\,\mathrm{PeV}$1, $\simeq 0.5\,\mathrm{PeV}$2–$\simeq 0.5\,\mathrm{PeV}$3, $\simeq 0.5\,\mathrm{PeV}$4–$\simeq 0.5\,\mathrm{PeV}$5, and $\simeq 0.5\,\mathrm{PeV}$6–$\simeq 0.5\,\mathrm{PeV}$7 (Coleman et al., 2021, Schroeder, 2021, Coleman, 2023, Clark, 2021). For the Auger-site prototype, usable or clean bands are identified at $\simeq 0.5\,\mathrm{PeV}$8–$\simeq 0.5\,\mathrm{PeV}$9 and $8\,\mathrm{km}^2$0–$8\,\mathrm{km}^2$1, after rejecting FM and TV interference (Verpoest, 2024, Verpoest et al., 11 Jul 2025).

A persistent architectural feature is detector elevation above the snow surface. Multiple design papers state that scintillators and antennas are elevated, mounted on poles, or otherwise kept above the snow in order to avoid snow-burial systematics and retain threshold stability over long operation (Schroeder, 2021, Coleman, 2023, Schröder, 8 Jul 2025, Schroeder, 27 Feb 2025).

3. Triggering, timing, calibration, and reconstruction formalism

The DAQ architecture is typically described as a local station hub that reads both scintillators and radio channels, implements a local trigger, and forwards time-stamped event data to the central DAQ. TAXI appears repeatedly as the field-hub or station DAQ platform, and prototype implementations use DRS4 switched-capacitor digitizers for the radio channels (Oehler et al., 2021, Verpoest et al., 11 Jul 2025, Venugopal, 11 Jun 2025). Published digitization rates include $8\,\mathrm{km}^2$2, $8\,\mathrm{km}^2$3, $8\,\mathrm{km}^2$4, and in some design studies $8\,\mathrm{km}^2$5–$8\,\mathrm{km}^2$6 for the radio chain (Verpoest, 2024, Verpoest et al., 11 Jul 2025, Schröder, 2023).

Trigger definitions differ across design papers and prototype modes, but the underlying logic is consistent: scintillator multiplicity provides the primary air-shower trigger and initiates radio waveform capture. Published thresholds include a local trigger of five panels each exceeding $8\,\mathrm{km}^2$7 within $8\,\mathrm{km}^2$8, a station trigger when $8\,\mathrm{km}^2$9 of 8 panels fire within $240\,\mathrm{m}$0, a local surface trigger if at least five of the eight single-panel channels exceed $240\,\mathrm{m}$1, and prototype triggers of $240\,\mathrm{m}$2 scintillator modules within $240\,\mathrm{m}$3 (Schroeder, 2021, Coleman, 2023, Schröder, 8 Jul 2025, Venugopal, 11 Jun 2025). The South Pole R&D paper also describes an earlier multiplicity requirement of $240\,\mathrm{m}$4 of 8 panels within a $240\,\mathrm{m}$5 window (Oehler et al., 2021). Early design descriptions mention optional radio self-triggering, but prototype operations emphasize scintillator-triggered radio readout (Schroeder, 2021, Venugopal, 11 Jun 2025, Verpoest, 2024).

Timing calibration is a central design requirement because arrival-direction reconstruction is based on sub-$240\,\mathrm{m}$6 relative timing. The literature variously quotes GPS-disciplined clocks, White Rabbit or WhiteRabbit synchronization, and statistical alignment to external detectors. At the Auger prototype, WhiteRabbit timing from the Auger CRS provides sub-ns absolute timestamps, while an earlier analysis synchronized daily to the Auger SD timestamp to better than $240\,\mathrm{m}$7 via statistical time-offset analysis (Verpoest et al., 11 Jul 2025, Verpoest, 2024). For the South Pole concept, published net timing precision is $240\,\mathrm{m}$8, with some studies quoting $240\,\mathrm{m}$9 station-to-station synchronization or sub-ns timing for White Rabbit–based systems (Schroeder, 2021, Schroeder, 27 Feb 2025, Venugopal, 11 Jun 2025).

Calibration procedures are correspondingly hybrid. Scintillator gain calibration is tied to MIP or VEM scales, with single-particle spectra, muon peaks, or LED/flasher systems used for gain monitoring (Verpoest et al., 11 Jul 2025, Schroeder, 27 Feb 2025, Clark, 2021). Radio calibration relies on lab transfer functions, antenna-response simulations, Galactic-noise monitoring, and forced-trigger background runs (Verpoest, 2024, Verpoest et al., 11 Jul 2025, Venugopal, 11 Jun 2025). A standard relation used in the radio analyses is the effective antenna area

$O(10\,\mathrm{km}^2)$0

with prototype estimates giving $O(10\,\mathrm{km}^2)$1–$O(10\,\mathrm{km}^2)$2 and $O(10\,\mathrm{km}^2)$3–$O(10\,\mathrm{km}^2)$4 across $O(10\,\mathrm{km}^2)$5–$O(10\,\mathrm{km}^2)$6 (Verpoest, 2024).

Reconstruction formalism is similarly split between the particle and radio channels. For the surface particle density, one commonly used parametrization is

$O(10\,\mathrm{km}^2)$7

where $O(10\,\mathrm{km}^2)$8 is the energy estimator and $O(10\,\mathrm{km}^2)$9 is treated as a mass-sensitive observable in the scintillator-only mass-separation study (Lohan, 17 Mar 2025). For the Auger prototype radio analysis, the field-strength lateral distribution is written as

$240\,\mathrm{m}$0

and the arrival direction is obtained from a plane-wave fit to antenna signal times (Verpoest et al., 11 Jul 2025). The radio signal-to-noise ratio is given in the prototype report as

$240\,\mathrm{m}$1

which directly connects background temperature, waveform RMS, and detectable pulse amplitude (Verpoest, 2024).

4. Prototype program at the South Pole and the Pierre Auger Observatory

The prototype program has two principal sites. A fully functioning prototype station was deployed at the South Pole in 2020 and upgraded in 2023, while a first full prototype station has operated at the Pierre Auger Observatory since December 2022 inside the $240\,\mathrm{m}$2-spaced SD433 water-Cherenkov array (Venugopal, 11 Jun 2025, Verpoest, 2024). The shared station concept at both sites consists of eight scintillator panels and three radio antennas, enabling hardware validation, DAQ validation, and air-shower cross-checks in distinct radio-noise environments (Verpoest et al., 11 Jul 2025).

At the South Pole, the prototype is described as an octagonal or compact station around a central TAXI crate, with typical detector separations of $240\,\mathrm{m}$3–$240\,\mathrm{m}$4 and three SKALA-v2 antennas mounted $240\,\mathrm{m}$5 above the snow surface (Venugopal, 11 Jun 2025). The readout is based on a scintillator multiplicity trigger, after which radio waveforms are dumped from DRS4 ring buffers. Offline event building matches radio, scintillator, and IceTop events within a $240\,\mathrm{m}$6 time window, producing “three-fold” air-shower candidates (Venugopal, 11 Jun 2025). In that prototype analysis, after an opening-angle cut $240\,\mathrm{m}$7 relative to IceTop, 102 events remained; the bulk of the angular-difference distribution is $240\,\mathrm{m}$8 (Venugopal, 11 Jun 2025). The same work reports that air showers with $240\,\mathrm{m}$9 as low as $8\,\mathrm{km}^2$0 were securely identified, below IceTop’s normal threshold of $8\,\mathrm{km}^2$1–$8\,\mathrm{km}^2$2 (Venugopal, 11 Jun 2025).

The Auger-site station is more extensively documented as a hybrid cross-calibration platform. The station has three arms of $8\,\mathrm{km}^2$3 length radiating from a central TAXI unit; two scintillator panels sit at each arm end, three SKALA antennas sit at the arm midpoints, and a central scintillator pair is collocated with the DAQ (Verpoest, 2024). It is located within the densest part of the Auger surface detector array, permitting hybrid coincidences with water-Cherenkov detectors and direct comparison with the Auger energy scale (Verpoest, 2024, Verpoest et al., 11 Jul 2025).

The first Auger report established two basic observational facts: Galactic noise is visible in the station data, and air showers were detected in coincidence between the prototype radio antennas and the Auger water-Cherenkov detectors (Verpoest, 2024). In the clean $8\,\mathrm{km}^2$4–$8\,\mathrm{km}^2$5 band, the frequency-domain RMS shows Galactic-noise dominance with a sidereal variation amplitude of $8\,\mathrm{km}^2$6–$8\,\mathrm{km}^2$7, and the effective system temperature is quoted as $8\,\mathrm{km}^2$8–$8\,\mathrm{km}^2$9 (Verpoest, 2024). Three months of stable data in May and August 2023 and January 2024 yielded 50 radio–SD coincident events, corresponding to $240\,\mathrm{m}$0 events/day above threshold (Verpoest, 2024).

A later Auger analysis, with $240\,\mathrm{m}$1 days of livetime from January 2023 to February 2024, reported 118 matched hybrid events after energy-quality cuts, corresponding to

$240\,\mathrm{m}$2

The SD433 energy distribution spans from a few $240\,\mathrm{m}$3, peaks near $240\,\mathrm{m}$4, and extends up to $240\,\mathrm{m}$5 (Verpoest et al., 11 Jul 2025). Directional agreement between radio and surface-detector reconstruction peaks at $240\,\mathrm{m}$6 in the later analysis and at $240\,\mathrm{m}$7 in the earlier report, with per-event radio angular uncertainty $240\,\mathrm{m}$8 (Verpoest et al., 11 Jul 2025, Verpoest, 2024). The later work also reports no significant difference in event rate or core-distance distribution between $240\,\mathrm{m}$9 and $\simeq 160$0 operation (Verpoest et al., 11 Jul 2025). Because the same SKALA-v2 antennas are used at Auger and at the South Pole, the prototype program is explicitly framed as a route toward cross-checks and potentially a cross-calibration of the energy scales between the two experiments (Verpoest et al., 11 Jul 2025).

5. Projected performance of the full array

Simulation studies and technical-design summaries describe a detector with substantially improved acceptance relative to IceTop. The most frequently repeated global claim is a factor of about $\simeq 160$1 increase in the aperture for coincident surface–in-ice air-shower measurements, arising from the larger area and larger zenith-angle coverage (Schröder, 2023, Schroeder, 27 Feb 2025, Schröder, 8 Jul 2025). In one simulation study the geometric aperture for coincident surface and in-ice events is given as $\simeq 160$2, compared to $\simeq 160$3 for IceTop (Lohan, 17 Mar 2025).

Threshold and efficiency figures depend on the specific detector model and trigger definition. The 2021 end-to-end simulation gives scintillator-array trigger efficiencies of $\simeq 160$4 at $\simeq 160$5 for vertical showers and full efficiency above $\simeq 160$6, with inclined-shower threshold shifting to $\simeq 160$7 near $\simeq 160$8 (Coleman et al., 2021). Later design summaries state a full-efficiency threshold for near-vertical proton showers of $\simeq 160$9, and one UHECR 2024 summary parameterizes the zenith dependence as $\times 10^{17}\,\mathrm{eV}$00 for $\times 10^{17}\,\mathrm{eV}$01 (Schroeder, 27 Feb 2025, Schröder, 8 Jul 2025). For the radio component, one detailed performance study reports a $\times 10^{17}\,\mathrm{eV}$02 trigger threshold of $\times 10^{17}\,\mathrm{eV}$03 for vertical showers and $\times 10^{17}\,\mathrm{eV}$04 for zenith angles $\times 10^{17}\,\mathrm{eV}$05–$\times 10^{17}\,\mathrm{eV}$06, reaching full radio efficiency by $\times 10^{17}\,\mathrm{eV}$07 and $\times 10^{17}\,\mathrm{eV}$08, respectively (Schröder, 2023). The Auger prototype, by contrast, infers a radio-detection threshold of $\times 10^{17}\,\mathrm{eV}$09 for the $\times 10^{17}\,\mathrm{eV}$10–$\times 10^{17}\,\mathrm{eV}$11 band at $\times 10^{17}\,\mathrm{eV}$12 lateral distance (Verpoest, 2024).

Angular and core-position resolutions also appear as energy-dependent ranges rather than single values. For scintillators only, the 2021 simulation reports arrival-direction resolution of $\times 10^{17}\,\mathrm{eV}$13–$\times 10^{17}\,\mathrm{eV}$14 at threshold and $\times 10^{17}\,\mathrm{eV}$15 above $\times 10^{17}\,\mathrm{eV}$16, with core-position resolution reaching $\times 10^{17}\,\mathrm{eV}$17 at multi-PeV energies (Coleman et al., 2021). The anisotropy study similarly quotes $\times 10^{17}\,\mathrm{eV}$18 at $\times 10^{17}\,\mathrm{eV}$19 and $\times 10^{17}\,\mathrm{eV}$20 above $\times 10^{17}\,\mathrm{eV}$21 (Hou, 2023). More optimistic system-level summaries for the combined detector state $\times 10^{17}\,\mathrm{eV}$22 combining surface and in-ice timing and $\times 10^{17}\,\mathrm{eV}$23 from the 8-panel layout, whereas other design papers quote core resolutions of order $\times 10^{17}\,\mathrm{eV}$24–$\times 10^{17}\,\mathrm{eV}$25 (Schroeder, 27 Feb 2025, Schroeder, 2021, Schröder, 8 Jul 2025). These are published projections from different reconstruction assumptions.

Energy reconstruction likewise improves when radio information is included. The scintillator-only simulation reports $\times 10^{17}\,\mathrm{eV}$26 at a few PeV and $\times 10^{17}\,\mathrm{eV}$27 above $\times 10^{17}\,\mathrm{eV}$28, corresponding to $\times 10^{17}\,\mathrm{eV}$29 relative error (Coleman et al., 2021). Later design summaries attribute $\times 10^{17}\,\mathrm{eV}$30–$\times 10^{17}\,\mathrm{eV}$31 electromagnetic-energy resolution to the radio+scintillator combination above $\times 10^{17}\,\mathrm{eV}$32 (Schroeder, 27 Feb 2025, Schröder, 8 Jul 2025). For the radio determination of shower maximum, design-level expectations of $\times 10^{17}\,\mathrm{eV}$33 or $\times 10^{17}\,\mathrm{eV}$34–$\times 10^{17}\,\mathrm{eV}$35 coexist with a South Pole prototype estimate of $\times 10^{17}\,\mathrm{eV}$36–$\times 10^{17}\,\mathrm{eV}$37 above $\times 10^{17}\,\mathrm{eV}$38 (Schröder, 2023, Schroeder, 27 Feb 2025, Schröder, 8 Jul 2025, Venugopal, 11 Jun 2025).

Mass separation is quantified most explicitly in the scintillator-plus-in-ice study, which excludes radio from the analysis. There, Linear Discriminant Analysis is used to combine observables, and the separation between two primaries $\times 10^{17}\,\mathrm{eV}$39 and $\times 10^{17}\,\mathrm{eV}$40 is measured by

$\times 10^{17}\,\mathrm{eV}$41

At $\times 10^{17}\,\mathrm{eV}$42 for vertical showers, the published proton-versus-iron FOM values are $\times 10^{17}\,\mathrm{eV}$43 for $\times 10^{17}\,\mathrm{eV}$44 only, $\times 10^{17}\,\mathrm{eV}$45 for $\times 10^{17}\,\mathrm{eV}$46 in-ice charge, $\times 10^{17}\,\mathrm{eV}$47 for $\times 10^{17}\,\mathrm{eV}$48 in-ice $\times 10^{17}\,\mathrm{eV}$49, and $\times 10^{17}\,\mathrm{eV}$50 for $\times 10^{17}\,\mathrm{eV}$51 true $\times 10^{17}\,\mathrm{eV}$52, with the paper noting that $\times 10^{17}\,\mathrm{eV}$53 corresponds to $\times 10^{17}\,\mathrm{eV}$54 overlap between the two distributions (Lohan, 17 Mar 2025). The central result is that the high-energy muons measurable by the in-ice array have the highest mass-separation power for showers whose energy is known from the surface array.

6. Scientific applications, sensitivities, and interpretation of design differences

The principal cosmic-ray application is multi-component composition analysis. The surface array supplies the electromagnetic shower size and lateral structure via scintillators, the radio footprint and $\times 10^{17}\,\mathrm{eV}$55 via antennas, and the in-ice detector supplies a high-energy muon observable. The literature repeatedly presents this combination as a means to separate light from heavy primaries and to probe the Galactic-to-extragalactic transition (Schroeder, 2021, Schröder, 2023, Schröder, 8 Jul 2025). One design summary states that the radio energy and $\times 10^{17}\,\mathrm{eV}$56, combined with the in-ice muon signal, permit measurements of $\times 10^{17}\,\mathrm{eV}$57 in the $\times 10^{17}\,\mathrm{eV}$58–$\times 10^{17}\,\mathrm{eV}$59 range (Schröder, 8 Jul 2025).

Large-statistics anisotropy studies are another recurring theme. Using a surface area of $\times 10^{17}\,\mathrm{eV}$60 depending on containment cuts, the anisotropy simulation predicts a 10-year sample of $\times 10^{17}\,\mathrm{eV}$61 reconstructed showers between about $\times 10^{17}\,\mathrm{eV}$62 and several $\times 10^{17}\,\mathrm{eV}$63 (Hou, 2023). The same study argues that the factor-of-eight increase in area relative to IceTop produces a $\times 10^{17}\,\mathrm{eV}$64 gain in statistical sensitivity to large-scale anisotropy (Hou, 2023).

Neutrino-veto operation is equally central. Published descriptions characterize the surface array as a charged-particle veto for downward-going atmospheric muons and air-shower backgrounds in the $\times 10^{17}\,\mathrm{eV}$65–$\times 10^{17}\,\mathrm{eV}$66 neutrino band (Schröder, 2023). Quantitative statements differ by analysis: Gen2-Surface is said to reduce the single-muon background by more than nine orders of magnitude in one observatory overview, while a later simulation-based study of the surface array gives southern-sky atmospheric-muon-background reduction by $\times 10^{17}\,\mathrm{eV}$67 orders of magnitude above $\times 10^{17}\,\mathrm{eV}$68 neutrino energy (Clark, 2021, Coleman, 2023). Another design paper quotes $\times 10^{17}\,\mathrm{eV}$69 veto efficiency for showers above $\times 10^{17}\,\mathrm{eV}$70 at $\times 10^{17}\,\mathrm{eV}$71, rising to $\times 10^{17}\,\mathrm{eV}$72 suppression of the background in neutrino analyses down to $\times 10^{17}\,\mathrm{eV}$73–$\times 10^{17}\,\mathrm{eV}$74 (Schröder, 2023). These claims are not contradictory so much as conditioned on different observables, zenith ranges, and analysis definitions.

PeV-photon searches and hadronic-interaction studies are additional explicit goals. The deep array provides a discriminator because hadronic showers produce in-ice muon bundles whereas photon showers are muon-poor; design papers identify this as the basis for southern-sky PeVatron searches (Schröder, 8 Jul 2025, Schroeder, 27 Feb 2025). Hadronic-interaction studies are motivated by the simultaneous access to low-energy muons and electromagnetic particles at the surface and TeV muons in the ice, with prompt-muon physics repeatedly cited as a target enabled by the enlarged coincidence aperture (Schroeder, 2021, Schroeder, 27 Feb 2025).

A common misconception is that the varying station counts, areas, and thresholds in the literature indicate incompatible designs. The papers instead present a stable detector concept with evolving baselines. Eight scintillator panels and three radio antennas per station are constant across the major design documents; what changes are the array boundary, whether bridging stations or IceTop-enhancement stations are included, and which performance definition is reported. Another misconception is that the radio subsystem is intended to replace the particle detector trigger. In the prototype and most baseline studies, radio is primarily externally triggered by scintillators and contributes high-value observables—electromagnetic energy and $\times 10^{17}\,\mathrm{eV}$75—rather than setting the lowest threshold (Verpoest, 2024, Venugopal, 11 Jun 2025, Lohan, 17 Mar 2025). The resulting picture is of a deliberately hybrid instrument whose performance derives from coincidence between complementary detector technologies rather than from any single subsystem alone.