For the in-game mission, see Atmos Ring (mission).
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The Atmos Ring (アトモスリング)[2] is one of the signature structures built in Aurelia's capital city, Griswall. It is a ring-shaped structure that encircles Griswall's central district, including its other signature structure, the Gaiuss Tower. It is officially known as the Aurelia Superconducting Synchrotron Laboratory (オーレリア・超伝導・シンクロトロン研究所) or ASSL.[2]

The Atmos Ring is primarily a particle accelerator research facility. Aurelia later designed Meson Cannons for the Atmos Ring to defend the capital, but their development was cut short. Leasath commandeered these Meson Cannons after capturing Griswall in the Aurelian War.


The Atmos Ring is a large ring surrounding Griswall. The ring measures 4.6 km in diameter and 14.5 km in circumference. The structure houses a synchrotron particle accelerator, where an accelerating particle beam can travel a closed-loop path. The Atmos Ring can accelerate particle beams to an energy of 6.4 teraelectronvolts (TeV).[2] These particle beams create mesons that decay into muons[3] to perform muon-catalyzed fusion, which provides power to Griswall. The Atmos Ring uses the residual synchrotron radiation to support research into materials science, atomic and nuclear particle physics, and developing new medicinal drugs.[2]

The Atmos Ring also features a defense system using the decayed muons. Large watchtowers divide the Atmos Ring into sections, and each watchtower supports a Meson Cannon. Aurelia designed Meson Cannons to weaponize the decayed muons and fire them at attacking aircraft or missiles.[3] They ended the Meson Cannons's construction prematurely due to rising development costs, political considerations for neighboring countries,[2] and the lack of an immediate threat.[3]

The Atmos Ring was designed to complement the appearance of the urban landscape. It re-uses many of the medieval ruins that surrounded the city's old town. The Atmos Ring also uses waterproof gates to prevent flooding from the river that encircles the ring. With the old town situated inside the ring, this design presents a landscape reminiscent of a medieval castle with a moat.[2]



The Aurelian government originally built the Atmos Ring to perform muon-catalyzed fusion to cover Griswall's massive power demand. The facility later supported scientific advances brought on by synchrotron radiation.[2] Aurelia also developed the Meson Cannon defense system to install on the Atmos Ring, but later canceled the development.[3]

The Atmos Ring had an issue early on: the decayed muons had a limited lifespan, only manifesting in short bursts. Aurelian engineers at the Monte Breeze Industrial Area began developing Meson Beam Stabilizing Regulators to solve this problem.[4]

Aurelian War

In October 2020, Leasath suddenly invaded Aurelia and captured Griswall within 10 days, taking the Atmos Ring under their control. They installed the Meson Cannons on top of the Atmos Ring to use them as a defensive weapon if Aurelian forces attempted to liberate the city.[2] They also captured the Meson Beam Stabilizing Regulators and attempted to install them into the Meson Cannons to increase their firepower. Gryphus One worked in conjunction with Aurelian ground forces to shoot down Leasath's transport aircraft carrying the regulators.[5][note 1]

Soon afterward, the Aurelian Liberation Corps entered Griswall and temporarily drove Leasath forces out of the city. They captured the Atmos Ring and attempted to disable the Meson Cannons. While Gryphus Squadron and Ninox Squadron entered the area, the ALC shut down all power to the Atmos Ring. Without any power, the Meson Cannons could not fire, but the Atmos Ring's gates opened up. Leasath forces outside the city tried to take advantage of this to enter the city, but Gryphus One destroyed all of the Leasath forces. After a failed Leasath cruise missile attack, Aurelian ground forces subsequently relieved the ALC and regained control of the Atmos Ring.[1][note 1]



  • The Atmos Ring's particle accelerator is quite similar to the Large Hadron Collider near Geneva, Switzerland. The LHC is also a synchrotron particle accelerator. It measures 27 km in circumference (12.5 km longer than the Atmos Ring) and can accelerate proton beams to an energy of 6.5 TeV (0.1 TeV higher than the Atmos Ring).
  • Proton beams don't directly generate synchotron radiation; the radiation requires electrons. The Large Hadron Collider's proton accelerators generate photoelectrons, which propagate secondary electrons that generate the radiation. This is most likely how the Atmos Ring generates synchotron radiation for its research as well.


  1. 1.0 1.1 The mission-specific information adheres to the canon guidelines set in Acepedia:Canon § Ace Combat X branching paths.


  1. 1.0 1.1 Wild Card, Ace Combat X: Skies of Deception.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 ACE COMBAT X -> 用語解説 (Glossary) -> アトモスリング (The Atmos Ring). Retrieved on 24 April 2018.
  3. 3.0 3.1 3.2 3.3 ACE COMBAT X -> 用語解説 (Glossary) -> メソンカノン (Meson Cannon). Retrieved on 24 April 2018.
  4. ACE COMBAT X -> 用語解説 (Glossary) -> MBSR. Retrieved on 24 April 2018.
  5. Joint Operation, Ace Combat X: Skies of Deception.