The Axion Dark Matter Hunt: MIT's DMRadio, BabyIAXO, and What Physicists Really Think About Discovery

Dark matter makes up roughly 85% of all matter in the universe, yet no one has ever directly detected it. Among the leading candidates for what that dark matter actually is stands the axion — a hypothetical particle first proposed to solve a separate puzzle in particle physics, the strong CP problem. Over the past few years, the hunt for the axion has accelerated dramatically. A new generation of experiments, from tabletop magnetic detectors to a 10-meter-long superconducting magnet that tracks the Sun, is narrowing the search space. Here is a current snapshot of the major efforts, the key people, and the prevailing sentiment in the field.

MIT's ABRACADABRA: The Pathfinder That Paved the Way

ABRACADABRA-10 cm — the name stands for "A Broadband/Resonant Approach to Cosmic Axion Detection with an Amplifying B-field Ring Apparatus" — was a lumped-element "haloscope" that used a toroidal magnet to look for oscillating electric currents induced by passing axions. It completed two physics runs between 2018 and 2020, setting world-leading exclusion limits on axion–photon couplings in the sub-μeV mass range (0.31–8.8 neV), though it found no axion signal . The experiment has now transitioned into a new role: in 2025, the ABRA-10 cm detector was repurposed for a high-frequency gravitational wave search, using a change in readout strategy . Its success established the technical foundation for the larger DMRadio program, which is now the central focus of MIT's axion search .

DMRadio: MIT's Next-Generation Phased Approach

The DMRadio suite is MIT's phased plan to cover axion masses below 1 μeV. All phases use the same core principle — a strong magnetic field converts axions into a detectable electromagnetic signal — but at increasing scale and sensitivity.

• DMRadio-50L — currently under construction at Stanford. It will search the 5 kHz – 5 MHz range using a lumped-element LC resonator with a toroidal magnet, and will also serve as a testbed for quantum sensors . Commissioning is underway, with the full cryogenic system now operational and data taking expected to commence soon .
• DMRadio-m³ — in the design phase. It is designed to reach the benchmark KSVZ and DFSZ QCD axion models across 10–200 MHz (41 neV – 0.83 μeV) and is preparing project execution plans . According to a 2025 design paper, achieving the primary science goal of sensitivity to DFSZ axions across 30–200 MHz would require a 3σ live scan time of 2.9 years .
• DMRadio-GUT — a longer-term future experiment targeting the GUT-scale QCD axion (100 kHz – 30 MHz) with definitive sensitivity .
• DMRadio-Core — a new geometry proposed in 2026 that uses a narrow-bore segmented solenoid to optimize signal collection, reducing stored magnetic energy while preserving sensitivity .

Jessica Fry: From Broadway to the Axion Hunt

Jessica Fry is a 5th-year physics PhD candidate at MIT's Laboratory for Nuclear Science, building specialized detectors for the DMRadio program. She has an unusual background — she was a professional Broadway performer before switching to physics. MIT's spotlight describes her transition as "from the Broadway stage to MIT's Laboratory for Nuclear Science." She says of the axion hunt: "It's a hard problem. But it's a tractable one. It is a fun hunt" . Fry was named to the Forbes 30 Under 30 – Science (2026) list for her work leading the search for dark matter . She has published 10 papers with nearly 200 citations .

BabyIAXO and the International Axion Observatory (IAXO)

BabyIAXO is an intermediate-stage "axion helioscope" that will search for axions produced in the Sun. It uses a custom superconducting dipole magnet — described by project coordinator Professor Matthias Schott of the University of Bonn as "the largest dipole magnet that's ever been constructed in particle physics" . The magnet is 10 m long with two 70 cm-diameter bores, operated at about −270°C and mounted on a moving platform to track the Sun for 12 hours a day .

The German Research Foundation (DFG) recently approved 6 million euros in funding through the Excellence Cluster "Color meets Flavor" at the Universities of Bonn, Siegen, and Dortmund to build the magnet system, which is now moving into construction . BabyIAXO is sited at DESY in Hamburg and will test the magnet, optics, and detector technologies for the full-scale International Axion Observatory (IAXO), which would have dramatically greater sensitivity to solar axions .

The Broader Field: What Physicists Really Think

The field is growing rapidly and there is genuine optimism, but "inevitable" is stronger than the evidence supports. Multiple experiments — ADMX, CAPP, HAYSTAC, ABRACADABRA, and others — have steadily narrowed the allowed parameter space. DMRadio-m³ and ADMX-EFR are poised to probe the most theoretically well-motivated QCD axion models (KSVZ and DFSZ) in the coming years . Many physicists involved describe the hunt as a "tractable" problem with a distinctive predicted signal . However, no axion signal has been detected yet, and the axion mass could lie in regions that remain experimentally challenging. The mood is best described as guarded optimism — the tools are finally arriving that could either discover the axion or definitively exclude it across wide ranges of mass, which would be a major result either way.