Samuel Cohen

Intelligence Summary: Samuel A. Cohen

Node Identity: Samuel Cohen is the inventor of the Princeton Field-Reversed Configuration (PFRC), one of the most credible compact fusion reactor concepts in the white-track (openly published) fusion ecosystem. His work at PPPL represents mainstream plasma physics research with direct applications to both terrestrial power and space propulsion.

Research:

• Princeton Field-Reversed Configuration (PFRC)
  • Compact FRC reactor using D-3He fuel
  • Low neutron emissions (aneutronic fusion approach)
  • 1-10 MW reactor scale
  • Applications: submarines, urban environments, space propulsion
  • PFRC-1 and PFRC-2 experiments achieved:
    • Electron temperatures >100 eV
    • 300 ms duration
    • Stability >10^4 times longer than tilt instability growth time
  • PFRC-3 design (~50% larger than PFRC-2)
  • FRC has >10x higher beta than tokamaks
  • Odd-parity Rotating Magnetic Field (RMF) heating
  • HTS (High Temperature Superconductor) coils
  • Magnetic nozzle for thrust (50-20,000 km/s exhaust velocity)

Patents:

• US11322265B2 — 'System and Method for Small, Clean, Steady-State Fusion Reactors' (2022-05-03)
  • Assignee: Trustees of Princeton University
  • Features: gas box, scrape-off-layer (SOL) widening, controllable exit orifice, ash extraction, reduced neutron emissions

Collaborations:

• Princeton Satellite Systems (PSS): Michael Paluszek, Stephanie Thomas, Christopher Galea
  • Direct Fusion Drive (DFD) rocket engine concept
  • Four joint PPPL/PSS patents
• LLNL: T.D. Rognlien
• NASA: JPL Advanced Space Propulsion Workshop

Evidence Calibration:

• ESTABLISHED: PPPL position, PFRC invention, patents, experimental results (PFRC-1/2)
• ESTABLISHED: PSS collaboration on DFD, IAEA FEC 2023 publication
• SPECULATIVE: Practical 1-10 MW reactor viability (experimental stage, not yet demonstrated at power scale)