Spherical Tokamak Experiment (ETE)

Intelligence Summary: ETE — Experimento Tokamak Esférico

Node Identity: The ETE (Experimento Tokamak Esférico) is a small spherical tokamak (low aspect ratio) entirely designed and constructed at INPE during the 1990s, achieving first plasma discharge in November 2000. ETE has a major radius of ~30 cm and minor radius of ~20 cm, with an Inconel 625 vacuum vessel providing 58 Conflat ports for diagnostics. Initial operating parameters achieved plasma currents of ~45 kA lasting ~4 ms, with electron temperatures up to 160 eV and densities of 2.2×10¹⁹ m⁻³. The design target for the first operational phase was plasma currents up to 200 kA lasting ~15 ms. ETE continues operating as of 2024.

Strategic Relevance: ETE is a modest but genuinely indigenous Brazilian fusion device — designed and built domestically rather than imported. While its parameters are far below reactor-relevant conditions, it provides hands-on tokamak operation experience, diagnostic development, and training that few countries in the developing world possess. The spherical tokamak configuration is strategically significant because it is the same concept being pursued by private fusion companies (Tokamak Energy, Commonwealth Fusion Systems) for compact fusion power plants. Brazil's early entry into spherical tokamak research (1990s) predates much of the current private fusion boom. The device's research objectives include exploring low aspect ratio tokamak plasma physics, plasma edge investigation, plasma heating by Alfvén waves, developing hot plasma diagnostics, and training in tokamak operation.

Technical Focus / Capabilities: ETE's technical parameters position it as an educational and exploratory device. Key researchers include Gerson Otto Ludwig (D.Sc., ITA), L.A. Berni, E. Del Bosco, J.G. Ferreira, R.M. Oliveira, and C.S. Shibata. The device was designed to allow even a modest machine to contribute effectively to the international fusion research effort, given the large number of unsolved physics problems in the spherical torus configuration. Under the CNEN-INPE Protocol of Intentions (signed October 10, 2022, extended to October 2026), ETE facilities host the provisional Laboratório de Fusão Nuclear (LFN), with a permanent LFN facility planned for Iperó, SP — described as "unique in Latin America."

Network Linkage: ETE is managed by CNEN as part of the National Fusion Program transition from INPE. The device is physically located at INPE facilities but under CNEN operational oversight through the LFN protocol. The planned permanent LFN at Iperó connects to Brazil's historical nuclear program site. IAEA Safeguards monitoring of CNEN provides international oversight of the fusion program's dual-use aspects.