Chapter 2
From the dominant tokamak design to innovative alternatives, exploring the diverse approaches to achieving controlled fusion on Earth.
The tokamak, a Russian acronym meaning "toroidal chamber with magnetic coils," has been the dominant approach to magnetic confinement fusion for over 50 years. Its design uses powerful magnetic fields to confine plasma in a donut-shaped (toroidal) chamber, keeping the 100-million-degree plasma away from the reactor walls.
The key insight of the tokamak is combining two magnetic field components: a strong toroidal field created by external coils wrapped around the torus, and a poloidal field created by a current flowing through the plasma itself. These fields twist together to form helical field lines that provide stable confinement.
The world's largest fusion experiment, a collaboration of 35 nations. ITER aims to demonstrate Q=10 sustained operation, producing 500 MW of fusion power from 50 MW of heating.
Korea's "artificial sun" holds the world record for sustained high-temperature plasma: 48 seconds at 100 million °C in 2024. KSTAR is a testbed for ITER technologies.
The Joint European Torus held the fusion power record (16 MW) for 25 years. JET pioneered D-T operations and trained a generation of fusion scientists.
The Experimental Advanced Superconducting Tokamak achieved 1,056 seconds of plasma operation in 2023, demonstrating long-pulse capability.
Stellarators create the helical magnetic field entirely with external coils, eliminating the need for plasma current. This makes them inherently steady-state capable, but the complex 3D coil geometry is challenging to design and build.
The world's largest stellarator, W7-X demonstrated that advanced optimization can achieve tokamak-like confinement in a steady-state-capable device.
Rather than confining plasma with magnets, inertial confinement uses powerful lasers to compress and heat a tiny fuel pellet so rapidly that fusion occurs before the plasma can expand. In December 2022, NIF achieved scientific breakeven with Q > 1.
NIF's 192 laser beams deliver 2 megajoules to a BB-sized target. In December 2022, NIF achieved fusion ignition with 3.15 MJ output from 2.05 MJ input.
A new generation of private companies is pursuing faster, cheaper paths to fusion, often using innovative approaches enabled by advances in superconducting magnets, computing, and materials.
| Company | Approach | Funding | Target |
|---|---|---|---|
| Commonwealth Fusion Systems | Compact tokamak (SPARC) | $2B+ | Q>2 by 2025 |
| TAE Technologies | Field-reversed configuration | $1.2B | P-B11 fusion |
| Helion Energy | Pulsed FRC | $600M | Electricity by 2024 |
| General Fusion | Magnetized target | $400M | Pilot plant 2025 |
| Tokamak Energy | Spherical tokamak | $250M | 100M°C achieved |
| Zap Energy | Sheared-flow Z-pinch | $200M | Compact device |
Traditional fusion magnets use low-temperature superconductors (LTS) that must be cooled to 4 Kelvin (-269°C). The recent development of high-temperature superconductor (HTS) tape, particularly REBCO (Rare Earth Barium Copper Oxide), enables much stronger magnetic fields in smaller packages.
Higher magnetic field strength (B) improves fusion performance dramatically because the fusion power density scales as B⁴. A doubling of magnetic field from 5T to 10T increases power density by 16×, enabling much more compact reactors.
Korea operates a comprehensive industrial cluster system. Korea Top 12 National Strategic Technologies (5th Science and Technology Master Plan 2023-2027): (1) Semiconductors and Displays (2) Secondary Batteries (3) Advanced Mobility (autonomous driving, UAM) (4) Next-Generation Nuclear (SMR) (5) Advanced Bio (6) Aerospace and Marine (7) Hydrogen (8) Cybersecurity (9) Artificial Intelligence (10) Next-Generation Communications (11) Advanced Robotics and Manufacturing (12) Quantum. 12 fields receive direct investment of 5 trillion KRW annually, cumulative 30 trillion KRW by 2030. Korea Major Industrial Clusters: Pangyo IT Cluster (1,300+ companies, 100 trillion KRW revenue), Gangnam Fintech (200+ companies), Songdo BT Bio Cluster, Daegu Medical Cluster, Ulsan Industry (shipbuilding, petrochemicals, automotive), Changwon Machinery, Changwon National Industrial Complex, Siheung and Banwol (SME manufacturing), Yeosu Petrochemicals, Pyeongtaek Semiconductor (Samsung Electronics Pyeongtaek Campus), Icheon and Cheongju Semiconductor (SK hynix Icheon and Cheongju Campuses), Asan Display (Samsung Display Asan Campus), Gumi Mobile (Samsung Gumi Campus), Pohang Steel (POSCO Pohang Steel Mill), Gwangyang Steel (POSCO Gwangyang Steel Mill), Dangjin Steel (Hyundai Steel Dangjin), Ulsan Automotive (Hyundai Motor Ulsan Plant), Asan Automotive (Hyundai Asan Plant), Kia Gwangju and Sohari, POSCO Gwangyang and Pohang Steel Mills, SK hynix Icheon and Cheongju, Samsung Electronics Hwaseong, Giheung, Pyeongtaek, Onyang, Cheonan, Asan Semiconductor Facilities. Major Industrial Complexes and Techno Valleys: Pangyo Techno Valley (1st 800 companies, 2nd 600 companies, 3rd 1,200 companies), Dongtan Techno Valley, Gwanggyo Techno Valley, Songdo IBD, Yeouido Financial District, Gangnam Teheran-ro Valley, Sihwa, Banwol, Gumi, Ulsan, Changwon, Geoje, Yeosu, Ulsan Mipo, Onsan, Cheongju, Iksan, Gwangyang, Yeosu, POSCO Gwangyang Steel Mill, Asan Bay, Seosan, Songdo, Incheon Airport, Sejong, Cheongna, Geomdan, Pyeongtaek Automotive Industrial Complex, Giheung Semiconductor Complex, Icheon Semiconductor Complex, Asan Display Complex, Gumi Mobile Complex, Changwon National Industrial Complex, Ulsan Mipo National Industrial Complex, Yeosu National Industrial Complex, Onsan National Industrial Complex. Korea Workforce Statistics: STEM undergraduate students 700,000 (26% of all university students), STEM graduate students 170,000, PhD researchers 140,000, STEM doctorates conferred 8,000 annually (Seoul National University 1,200, KAIST 800, POSTECH 400, Yonsei University 700, Korea University 600, UNIST 250, DGIST 100, GIST 200, KISTI 50, KIST and ETRI postdoctoral programs 1,000), information security experts 300,000 (KISA-trained and private), AI experts 50,000 (NIA, IITP, NIPA, Samsung, LG, SK, NAVER, Kakao trained), semiconductor experts 260,000 (Samsung Electronics 60,000, SK hynix 30,000, DB HiTek, SK siltron). National R&D Project Operation: National R&D projects 100,000+ annually (MSIT 35,000, MOTIE 25,000, MSS 20,000, MOE 15,000, others 5,000), R&D participating institutions 25,000+, R&D participating researchers 530,000, National R&D output (papers, patents) 540,000 annually. Korea Corporate R&D Investment Top 10 (2024): Samsung Electronics 28 trillion KRW, LG Electronics 9 trillion KRW, SK hynix 8 trillion KRW, Hyundai Motor 6 trillion KRW, Kia 4 trillion KRW, LG Chem 3.5 trillion KRW, LG Display 3.2 trillion KRW, POSCO 3 trillion KRW, Samsung SDI 2.7 trillion KRW, SK Innovation 2.5 trillion KRW.
Korea leads global standardization cooperation in 4th industrial revolution technologies. Korea Quantum Technology Standards: "Quantum Science and Technology Comprehensive Development Plan 2024-2030" (8 trillion KRW R&D), National Quantum Science and Technology Committee, MSIT Quantum Technology Bureau, KIST Quantum Information Research Division, KAIST Quantum Graduate School, POSTECH Quantum Science and Technology Division, KAIST IQC, Seoul National University Quantum Information Center, Korea Institute for Advanced Study Quantum Computing Division, KRISS Quantum Measurement Standards Center, SK Telecom QKD, KT QKD, LG U+ QKD, Samsung SDS PQC, Easy Security, CryptoLab Quantum-Resistant Cryptography, KS X ISO/IEC 18033-3, NIST PQC ML-KEM/ML-DSA/SLH-DSA Korean adoption, QKD ETSI GS QKD series Korean Profile. Korea Next-Generation Communications (5G/6G) Standards: 5G subscribers 35 million, 5G base stations 350,000, 5G dedicated networks 16 operators, 6G Acceleration Council (MSIT 2024), 6G commercialization target 2028, 3GPP Release 18/19/20 Korean participation, KS X 3GPP, Samsung Research 6G, LG Electronics 6G, KT 6G, SK Telecom 6G, LG U+ 6G, NIA, ETRI, KAIST, POSTECH, Seoul National University 6G Research Division, O-RAN ALLIANCE Korean Chair Company, M-CORD, OpenRAN Korean Cooperation. Korea AI Standards: KS X ISO/IEC 22989 (AI Concepts and Terminology), KS X ISO/IEC 23053 (AI System Framework), KS X ISO/IEC 5338 (AI System Lifecycle), KS X ISO/IEC 24029 (AI Trustworthiness and Robustness), KS X ISO/IEC 24028 (AI Trustworthiness), KS X ISO/IEC 23894 (AI Risk Management), KS X ISO/IEC 38507 (AI Governance), KS X ISO/IEC 42001 (AIMS Operations System), KS X ISO/IEC 42005 (AI Impact Assessment), AI Framework Act (effective July 2026) Enforcement Decree, Mandatory ex-ante impact assessment for high-impact AI, Samsung Research HyperCLOVA X, LG AI Research EXAONE, SK Telecom A., KT Media AI, NAVER Clova, Kakao i Korean foundation models. Korea Bio Standards: KS X ISO 20387 (Biobanking), KS X ISO 21709, KS X HL7 FHIR R5, SNOMED CT, LOINC, KCD-8, ICD-11, OMOP CDM v5.4, CDISC SDTM, DICOM, HL7 V2, HL7 CDA, MFDS GMP, MFDS Good Tissue Practice, MFDS AI Medical Device Guidelines (50+ approvals), KRIBB, KRICT, KFRI, KIST, KAIST, POSTECH Bio R&D Centers, Samsung Biologics, Celltrion, SK Bioscience, GC Biopharma, LG Chem, Chong Kun Dang, Yuhan Korean Bio Pharmaceuticals, 6 Major Hospitals (Seoul National University, Samsung, Asan, Severance, Bundang Seoul National University, Korea University) Clinical Trial Infrastructure. Korea Aerospace Standards: Korea AeroSpace Administration (KASA, established May 27 2024), MSIT, Ministry of National Defense, KARI, KASI, KIGAM, ETRI, KAI, Hanwha Aerospace, Hanwha Systems, LIG Nex1, CCSDS, ITU, NORAD, IADC, NASA, ESA, JAXA, CNSA, ISRO Korean Cooperation, KS W ISO 14620, KS W ISO 11227, KS W ISO 27026, Nuri Rocket KSLV-II, KSLV-III, Danuri KPLO, Next-Generation Reconnaissance Satellite 425 Project, Arirang, Cheollian, KOMPSAT, CAS500 series. Korea Secondary Battery Standards: "3rd Secondary Battery Industry Development Strategy 2024-2030", MOTIE Secondary Battery Bureau, LG Energy Solution, Samsung SDI, SK On, POSCO Future M, EcoPro BM, L&F, DI Dongil, Samsung SDI Korean Secondary Battery 6 Companies, KS C IEC 62660, KS C IEC 62619, KS C IEC 62133, UN ECE R100, UN/ECE R136 Korean Adoption. Korea Semiconductor Standards: Samsung Electronics (HBM3E, HBM4, DDR5, LPDDR5X), SK hynix (HBM3E 12-Hi, HBM4), DB HiTek, SK siltron, SK Enpulse, Dongjin Semichem, Seoul Semiconductor, Simmtech, Samsung Display, LG Display, JEDEC, SEMI, IEEE, KS C IEC 60068, UCIe 1.1/2.0, CXL 3.0/3.1, HBM4 Standardization, DDR6 Standardization, LPDDR6 Standardization, MRAM, ReRAM, PCRAM Korean Standards Adoption.