02 // Candidate Accelerator Architecture
Gram-scale annual production requires a dedicated accelerator facility beyond the capacity of any current research installation. The candidate architecture — designated the Halo Ring — is a 10 km diameter subterranean superconducting synchrotron powered by a dedicated Stellar Furnace reactor providing 20 GW of continuous beam power.
The Production Chain
1.Source. Hydrogen gas, ionized to bare protons. Standard duoplasmatron or RF ion source.
2.Acceleration. Superconducting RF cavities accelerate protons to collision energy (multi-GeV). Advanced accelerator R&D including Maxwell Continuum plasma wakefield stages targets compact acceleration gradients that could reduce ring footprint in future generations.
3.Target. The beam strikes a rotating iridium target. Iridium is selected for its combination of high atomic number (Z=77, maximizing pair production cross-section), highest density of any element (22.56 g/cm³), and extreme melting point (2,446°C). The target rotates to distribute thermal load across the full circumference.
4.Magnetic separation. A pulsed dipole field downstream of the target bends negatively charged antiprotons away from the positively charged proton debris. The AP-1 uses a 4π-steradian magnetic bottle rather than a narrow-acceptance beamline — capturing antiprotons emitted in all directions from the target.
5.Deceleration. A dedicated decelerator ring reduces antiproton kinetic energy from GeV to keV. Stochastic cooling followed by electron cooling. Cycle time: approximately 100 seconds per batch at CERN; the AP-1 targets 1 second through higher-field cooling solenoids and shorter orbit circumference.
6.Trapping. Cooled antiprotons are injected into Penning trap arrays for long-term storage, antihydrogen synthesis, or transfer to portable containment units.