The Experiment – Directional Dark Matter Search

CYGNO04 build phase

CYGNO04 is where directional dark matter gets real.

CYGNO04 is a 400 L underground technology demonstrator for directional dark matter. It is designed to turn optical-readout tracking into one of the largest and most precise directional detector systems of its kind, and to prepare the scale-up to CYGNO30.

Build undergroundTurn the optical TPC concept into a radiopure detector with stable gas, shielding, services, and commissioning at scale.

Image tracksUse triple-GEM amplification, six single-photon-sensitive cameras, and almost 60 million pixels to preserve topology.

Add depthCombine optical projections with 16 PMTs that resolve the light development needed for the third coordinate.

Prepare CYGNO30Use CYGNO04 as the demonstrator for a future approximately 30 m³ directional detector.

400 Lfiducial volume for the CYGNO04 demonstrator

He/CF₄ 60/40low-density gas mixture at atmospheric pressure

~600 gtarget mass for low-mass recoil searches

1 kg·yeartarget exposure for the demonstrator program

Dual-sided TPCtwo mirrored drift volumes around the center

2 × 50 cmdrift regions for ionization electrons

1 common central cathodeshared electrode defining the drift field

Triple-GEMamplification stage that turns ionization into detectable light

6 camerassingle-photon-sensitive optical views of the tracks

~60 million pixelsdetailed imaging of track topology

16 PMTstime development of the light signal

3D trackingcamera projections and PMT information combined in reconstruction

30 m³future CYGNO30 scale-up goal

Optical TPC technology

How CYGNO04 turns light into direction.

A dark-matter candidate event is not treated as a single flash. CYGNO04 records the track image, adds depth information, and reconstructs the event direction.

The detector is also a data-intensive instrument: online machine learning detects tracks and triggers acquisition, while reconstruction and machine-learning analysis classify events and extract physics observables.

Ionization track

A particle produces an ionization track in the He/CF₄ gas.

Drift

Electrons drift up to 50 cm toward the triple-GEM amplification stage.

Light production

The GEMs amplify the signal and produce light near the readout plane.

Camera image

Six cameras image the track topology with almost 60 million pixels.

Online trigger

An online machine-learning algorithm detects tracks and triggers data acquisition.

Third coordinate

Sixteen PMTs resolve the time development of the light signal, adding depth to the 2D projection.

Classification

Reconstruction and machine learning classify the event and extract its direction.

Detector evolution

From optical-readout prototypes to CYGNO30.

A decade of optical-readout R&D is converging on CYGNO04, the technology demonstrator that bridges prototypes and a future CYGNO30 detector with an approximately 30 m³ target volume.

ORANGE

Early prototype detector for CYGNO technology development.

LEMON

Prototype stage in the detector evolution toward larger optical TPC systems.

LIME

First CYGNO prototype operated underground at LNGS, used to test materials, shielding, and detector operation.

CYGNO04

The current scale-up: a radiopure optical TPC build that turns the prototype chain into a world-leading directional detector.