PrincetonFUSION SYSTEMS Direct Fusion Drive For the Gravitational Lens Mission
Artist’s rendering of DFD concept PFRC-2 in operation at PPPL Outline
DFD background Deep space SGL mission DFD/PFRC research update
PrincetonFUSION 2 SYSTEMS 6/24/19 PRINCETON FIELD REVERSED CONFIGURATION (PFRC)
PrincetonFUSION 3 SYSTEMS 6/24/19 PFRC Technology is Simple, Small, and Clean
Field Shaping RF Heating Ø Simple Coils Fuel Antenna Mirror Coil - Linear array of magnetic coils
Ø Small D-3He Fusion - FRC: Field-Reversed Configuration, a compact toroid - Size limited to 1-10 MW Coolant Ø Clean Exhaust Cool Plasma Energy Absorbed Heat and Ash Extraction - Very few damaging particles generated PFRC Schematic - No radioactive or hazardous fuels required Result: cheaper and faster to develop than other fusion concepts Electrolysis D2O Auxiliary Power O2 - Fusion power has only been generated in large Unit Startup Tokamaks (PPPL TFTR, JET) RF Generator Coil Radiator Refrigerator Gas - Large machines are expensive to develop and only D Box Plasma HTS Coil Blanket useful for large centralized power plants, ex. ITER Coil Cooling 3He Space Thermal Conversion PFRC is based on plasma heating experiments neutrons Bremsstrahlung Generator Synchotron
Brayton taking place at Princeton Plasma Physics Lab Shielding Coolant Radiator Heat Engine - PFRC-1, complete, PFRC-2, now operating Space version subsystems PFRC = Princeton Field-Reversed Configuration
PrincetonFUSION 4 SYSTEMS 6/24/19 Dual-Use Technology: PFRC becomes Direct Fusion Drive
Field Shaping RF Heating Field Shaping RF Heating Coils Fuel Antenna Coils Fuel Antenna Mirror Coil Nozzle Coil
D-3He D-3HeD-3He Fusion FusionFusion Exhaust Plume Coolant Exhaust Propellant
Cool Plasma Energy Absorbed Heat and Ash Extraction Cool Energy Absorbed Ion Acceleration Plasma PFRC: Princeton DFD: Direct Fusion Drive Field-Reversed • PFRC with an open end Configuration • Exhaust becomes a rocket • Closed at both ends plume • Exhaust cooled and • Power AND Propulsion in recycled one device
PrincetonFUSION 5 SYSTEMS Our Choice: Deuterium & Helium-3
Main Fusion Reaction Power ⁃ D + 3He ® 4He (3.6 MeV) + p (14.7 MeV) 98.4%
+ ® +
Side reactions 3 ⁃ D + D ® T (1.01 MeV) + p (3.02 MeV) 0.88% (3x more He than D) ⁃ D + D ® 3He (0.82 MeV) + n (2.45 MeV) 0.72% ⁃ D + T ®4He (3.5 MeV) + n (14.1 MeV) <0.05% T ® cooled and exhausted before it can fuse 3He ® exhausted 4He ® exhausted p ® exhausted n ® deposit energy in walls as heat
PrincetonFUSION 6 SYSTEMS PFRC is DIFFERENT than other fusion concepts
Simple Small Clean • Linear array of • Plasma radius • D-3He fuel magnets ~25 cm • Exhaust tritium • Easy to assemble • Reactor is 1-2 m before it can fuse diameter • <1% power in neutrons
PrincetonFUSION 7 SYSTEMS PFRC-2 Experiment in Action at PPPL
PrincetonFUSION 8 SYSTEMS SPACE APPLICATIONS
PrincetonFUSION 9 SYSTEMS 6/24/19 Direct Fusion Drive
Field Shaping RF Heating Fuel Coils Antenna Nozzle Coil
D-3He Fusion Exhaust Plume Propellant Cool Energy Absorbed Ion Acceleration Plasma
PrincetonFUSION 10 SYSTEMS Faster Trips to Deep Space Need Fusion Propulsion
What can you do with a 1-2 MW fusion engine and a 10,000 kg mission?
1 year 2 years 3 years 4 years 5 years
1 AU 5 AU 10 AU 20 AU 30 AU 40 AU 2 MW 1 MW 0.6 MW
PrincetonFUSION 11 SYSTEMS Space Power
High power difficult to achieve in space A 1 MW solar array is huge, as big as the ISS ⁃ Large solar arrays introduce severe attitude control problems 1 MW array 30% efficient ⁃ High efficiency cells are expensive - $500/watt Radioisotope Thermal Generators (RTGs) are used 109 m today for outer planet missions ⁃ Expensive and heavy ⁃ Power limited to ~ 200 W ⁃ Unpopular with the public One alternative for lunar and Mars bases is small fission reactors like Kilopower A small, clean fusion reactor would have wide applicability ⁃ Not require any dangerous fuels
PrincetonFUSION 12 SYSTEMS 6/24/19 Solar Gravitational Lens Mission
At and beyond 650 AU, the Sun’s gravity bends light from a planet enough to focus it on a telescope This focus extends semi-infinitely A 1 m diameter telescope could resolve 3 km features on a planet 100 light years away Baseline plan requires a $1.5B SLS launch and 50 years of transit time and has only 200 W power for operations DFD would get there in 13 years with 1 MW of power for operations with launch on a $60M Falcon 9
http://www.airspacemag.com/daily-planet/ultimate-space- telescope-would-use-sun-lens-180962499/ PrincetonFUSION 13 SYSTEMS 6/24/19 SGL Mission
Need to maneuver to keep the spacecraft on the focal line One mission option is to power a swarm of satellites by laser from the main spacecraft ⁃ Technology developed for a Pluto lander
PrincetonFUSION 14 SYSTEMS 6/24/19 RECENT WORK
PrincetonFUSION 15 SYSTEMS 6/24/19 PFRC Research and Development
DOE ARPA-E grant $1.25M underway ⁃ Plan to demonstrate 1 keV (11,000,000 degree-Kelvin) ion heating § Almost as hot as the center of the sun! ⁃ Produce a design for a portable fusion plant including all subsystems ⁃ 18 month duration NASA Phase I and II STTR $900K ⁃ Demonstrate a superconducting coil for a PFRC machine NASA Phase I STTR $150K ⁃ Build a prototype of RF board for the plasma heating NASA NIAC Phase I and Phase II $650K ⁃ Design Pluto Orbiter mission ⁃ Advance the development of a flight engine
Coming this summer!
PrincetonFUSION 16 SYSTEMS 6/24/19 PFRC Programmatic Support from NASA and DOE
MNX PFRC-1 PFRC-2 DOE 1998-2015 DOE FES 2002-2009 DOE FES 2010-2016
NIAC STTRs ARPA-E OPEN NASA 2016-2019 NASA 2017-2020 2019-2020
PrincetonFUSION 17 SYSTEMS Experimental Results
Highlights: Long-pulse with LN2 (2019-05-06)
The first plot shows the interferometer I time: 16:10:00 signal vs time during an RMF pulse. I pulse width: 19 ms I RMF power: ⁃ The signal is proportional to the density (top 37.9 kW/0.69% ⁃ The density peaked at 6 x 1012 /cc, 4ms into I RMF absorbed: 9.0 kW the discharge, following the application of a I Bcenter:169G supersonic gas puff. I CC pressure: 1.04 mTorr The bottom plot shows raw output I CC P :+0.97mTorr I SDD1 counts: 234/s from an Silicon Drift Detector (SDD) x- I SDD2 counts: 31/s ray detector looking at the plasma.
⁃ Visible are spectral lines of Oxygen and Iron, Eugene S. Evans Research Update — PFRC group meeting May 10, 2019 2/12 and broad-spectrum Bremsstrahlung x-rays. ⁃ This Bremsstrahlung is indicative of a 639 eV Maxwellian distribution.
PrincetonFUSION 18 SYSTEMS 6/24/19 Superconducting Coil
NASA STTR to study the effect of plasma currents on low temperature superconducting coils LTS supplied by Superconducting Systems, Inc. Pulsed Copper Coil (PCC) to simulate the plasma is shown
PrincetonFUSION 19 SYSTEMS 6/24/19 Brayton Topping Cycle
CO2 Brayton Cycle Engine with Recuperator and Topping Use tuned low band
T4T: 2000.0 K P4T: 2.9 Atm gap semiconductors to T3: 1001.0 K P3: 3.0 Atm
T4: 1589.0 K P4: 2.9 Atm T2: 490.9 K absorb energy from P2: 3.0 Atm T1: 300.0 K P1: 1.0 Atm the CO2 spectral line T6: 580.9 K T5: 1091.1 K P5: 1.0 Atm Potentially increase P6: 1.0 Atm Thermal efficiency: 61.45 % Mass flow: 0.31 kg/s Turbine work output: 0.28 MW Topping work output: 0.12 MW the overall heat Compressor work input: 0.08 MW Net Work: 0.26 MW recovery efficiency Recuperator effectiveness: 0.85
20 1020 10 Also applicable to 3 3 2 2
1 1
0 0 RTGs and NASA’s 0 0.5 1 0 0.5 1 E (eV) 1 E (eV) Broad-spectrum thermal emitter Broad-spectrum waste power: 60% Kilopower fission 0.5 Heat source 0 0 0.5 1 E (eV) 1020 1020 3 reactor 3 Photovoltaic spectral efficiency 2 2
1 1
0 0 0 0.5 1 0 0.5 1 E (eV) E (eV) Working fluid Sharp-spectrum thermal emitter Sharp-spectrum waste power: at peak efficiency as low as 10%
PrincetonFUSION 20 SYSTEMS 6/24/19 Summary
DFD enables interstellar pre-cursor missions like the SGL mission ⁃ Drastically reduced mission times and more power for science with a specific power of 1 kW/kg ⁃ Missions to nearby stars would require higher specific powers Ongoing work under ARPA-E will demonstrate ion heating to fusion relevant temperatures ⁃ Follow on machine will reach fusion relevant conditions Work under the NASA STTR supports balance of plant engineering
PrincetonFUSION 21 SYSTEMS 6/24/19 Contact Information
Michael Paluszek [email protected]
Stephanie Thomas [email protected]
Dr. Charles Swanson [email protected]
Dr. Samuel Cohen [email protected]
Princeton Satellite Systems 6 Market St. Suite 926 Plainsboro, NJ 08536 (609) 275-9606 http://www.psatellite.com
PrincetonFUSION 22 SYSTEMS 6/24/19