FAZIA Collaboration

The FAZIA internationnal collaboration regroups more than 30 nuclear physicists from France, Italy, South Korea, Poland and Spain. We designed and built a new-generation charged particle detector array for nuclear structure and reaction studies using heavy-ion collisions with stable and radioactive beams. FAZIA is operating since 2018 in GANIL.

October 23, 2025
2 min read

FAZIA (Forward A and Z Identification Array) is a new-generation array for charged particles detection and identification. It operates in the domain of heavy-ion induced reactions around the Fermi energy (10-100 MeV/nucleon) with greatly enhanced isotopic identification capabilities. The determination of the charge and mass of all reaction products is essential to advance knowledge on the density dependence of the Equation of State isovector part, in-medium transport properties of nuclear matter, and clustering effects at very low densities as well as nuclear structure properties. The FAZIA blocks are based on the ΔE-E technique with highly uniform silicon detectors, and Pulse-Shape Analysis (PSA) techniques for identification in a single detector. Dedicated on-board electronics comprising both analogue and digital stages was developed in order to push the identification capabilities close to their intrisic limits.

The first commissioning experiment with 4 FAZIA blocks was carried out at LNS Catania in 2015. From 2015 to 2018, 5 experiments were performed with either 4 or 6 blocks. The mass and charge identification performance of these blocks is exceptional and unique: for fragments punching through the first silicon detector (300µm), isotopic resolution is achieved up to Z=25, while the Z & A of slower fragments stopping in the first silicon is obtained up to Z=20. All heavier fragments can be identified in Z.

Since 2018, 12 FAZIA blocks are coupled with the INDRA multidetector in GANIL. For this the most forward rings of INDRA (up to 14 deg. polar angle) have been removed in order to be replaced by a wall of FAZIA blocks. This provides complete mass and charge identification of forward emitted fragments in FAZIA, while the remaining INDRA rings, completing the 4π angular coverage, allows to accuratly select the reaction mechanism which is essential for comparison with theoretical predictions. Four experiments were performed with this setup:

Isospin transport and the Density Dependence of the Symmetry Energy (E789), Olivier Lopez, Silvia Piantelli
Extending our knowledge of Warm Dense Nuclear Matter in the low density region (E818), Rémi Bougault, Giovanni Casini
Measurement of the 12C Hoyle state radius via double-excitation inelastic scattering (E881), Diego Gruyer, Daniele Dell’Aquila
Impact of projectile-target size asymmetry on the isospin equilibration rate extracted from quasiprojectile breakup reactions (E884), Caterina Ciampi, John Frankland

Tags:
Fazia