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Thea Energy is commercializing fusion energy using stellarator physics and computer-controlled planar coil arrays. We are seeking a Principal Magnet Cryogenics Engineer to lead the complete program lifecycle—from concept through commissioning—of large-scale cabled High-Temperature Superconducting (HTS) magnet systems for next-generation fusion reactors.
You will hold end-to-end technical ownership for cryogenic design, thermal-hydraulic modeling, forced-flow cooling distribution, and cryogenic integration of large-scale CICC (Cable-in-Conduit Conductor) or advanced stacked-tape HTS magnets. You will bridge megawatt-scale cryogenic plant engineering with microscopic thermal-hydraulic magnet behavior, leading multi-disciplinary teams through multi-million-dollar hardware deliverables.
Key responsibilities include:
- Program Lifecycle Ownership: Lead the complete lifecycle (Conceptual, Preliminary, Detailed Design, Qualification, Fabrication, Assembly, Commissioning, and Decommissioning) for large-scale HTS fusion magnet cryogenic systems.
- Cryo-Thermal System Architecture: Design, model, and validate gaseous helium (gHe) or sub-cooled liquid nitrogen (sLN2) thermal management systems tailored to high-field HTS cabled conductors.
- Thermal-Hydraulic Modeling: Perform dynamic thermal-hydraulic analysis, transient load modeling (nuclear heating, AC losses, eddy currents, ramp rates), and margin calculations under operational and fault conditions.
- Quench & Fault Management: Own the cryogenic response strategy during quench events, including rapid helium expansion, overpressure relief sizing, burst disc integration, and thermo-mechanical stress containment.
- Large-Scale Infrastructure & Plant Integration: Define requirements for megawatt-class cryogenic plants, cold compressors, heat exchangers, sub-coolers, helium distribution boxes, and low-heat-leak transfer lines.
- Joints & Current Leads: Oversee cryogenic thermal management for high-current demountable or permanent HTS joints and conduction-cooled hybrid (HTS/LTS) gas-cooled current leads (60+ kA).
- Vendor & Subcontractor Governance: Manage major sub-contracts for large-scale cryogenic infrastructure, conductor fabrication, pressure vessels, and vacuum insulated systems (cryostats).
- V&V and Commissioning: Plan and execute full-scale cryogenic and high-current magnet test campaigns, leading cool-down, steady-state operation, quench mitigation, and warm-up procedures.
REQUIREMENTS:
- 10-15+ years of direct experience in cryogenic engineering and thermal-hydraulic design for superconducting magnet systems, with primary focus on HTS tape/cable architectures (REBCO/BSCCO).
- Large-scale fusion/physics program delivery: Proven track record of ownership over large-scale (>$10M+) magnet work packages within fusion energy programs (e.g., W7x, ITER, JT60SA, KSTAR, DEMO) or major scientific facilities (e.g., CERN, FERMILAB).
- Cabled HTS architecture: Demonstrated expertise in high-current (tens of kA) cabled HTS configurations (e.g., Cable-in-Conduit Conductors, stacked tape conductors) and forced-flow cooling strategies.
- Full lifecycle track record: Experience taking at least one major superconducting magnet or cryogenic system from initial concept through initial cool-down and operational validation.
- Regulatory & code compliance: Deep familiarity with pressure vessel standards applied to cryogenic temperatures (ASME BPVC Section VIII, EN 13445, B31.3) and cryogenic safety standards (ISO 21010/CGA).
- HTS material physics: Solid understanding of critical surfaces for REBCO coated conductors, strain sensitivity, thermal margin assessment, and current sharing regimes.
- Cryogenic fluids & thermophysical properties: Mastery of low-temperature fluid dynamics (gHe, sLN2) using database tools.
- Transient thermal analysis: Deep domain knowledge of AC losses (coupling, hysteresis, flux creep), nuclear volumetric heating, heat-leak budgets, and conduction/radiation thermal shielding (MLI design).
- Instrumentation & controls: Extensive knowledge of low-temperature thermometry (Cernox, TVO, optical fibers/FBG), cryogenic flow meters, pressure transducers, and cryogenic valve telemetry.
- Computational tools: Proficiency in finite element analysis (FEA) and thermal-hydraulic system modeling tools (e.g., COMSOL Multiphysics, ANSYS Thermal/CFD, MATLAB/Simulink).
- System engineering & requirements flowdown: Capability to write clear system requirement documents (SRDs), interface control documents (ICDs), and lead major design reviews (CoDR, PDR, CDR).
- Leadership & team mentorship: Demonstrated ability to lead cross-functional engineering teams (structural, electrical, vacuum, systems) and mentor junior magnet/cryogenic engineers.
- Strategic risk mitigation: Mastery of FMEA applied to cryogenic system failures, vacuum loss, and runaway quench scenarios.
