2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/82238Spin waves, or magnons, in the anti-ferromagnetic $α$ phase of solid oxygen provide a novel mechanism for ultra-cold neutron (UCN) production. Magnons dominate the energy exchange mechanisms for cold neutrons and UCN in solid $α$-oxygen, much in the same way as do phonons in solid deuterium superthermal UCN sources. We present calculations of UCN production and upscattering rates in S-O$_2$. The results indicate that S-O$_2$ is potentially a much more efficient UCN source material than solid deuterium.9 pages, 7 figuresNuclear Theorytext