plasmoid
Fusion and self-organising plasma physics, computed. Every function reproduces a published number, and the proposals that promise more (cold fusion, Pais's fusion device, magnetically suppressed bremsstrahlung, overunity plasmoids) are set against the limit they have to beat.
- Getting through the Coulomb barrier: tunnelling and Gamow peaks, Bosch–Hale reaction rates, the p–¹¹B fits, the Lawson criterion, electron screening, muon catalysis, and gravity's way of doing it in stars.
- Pinches and the plasma focus: Bennett equilibrium, the Pease–Braginskii current, Lee's plasma-focus scalings, and the pinch's gravitational twin, the self-gravitating filament.
- Plasmoids: Taylor relaxation (
∇×B = λB, what a plasma settles into by itself), spheromaks, field-reversed configurations, and reconnection, slow (Sweet–Parker) and fast (plasmoid-mediated). - Aneutronic power: Q-values, the neutrons D–³He still makes, and p–¹¹B's race against bremsstrahlung and synchrotron radiation.
- Electricity without a steam cycle: multi-stage direct converters, inductive recovery in pulsed machines, and the plant arithmetic.
Install
Example: the Coulomb barrier, and how fusion gets past it
use ;
// D–T touching at 3.24 fm: a 444 keV barrier.
let barrier = coulomb_barrier;
// At 10 keV the reactions happen at the Gamow peak, 31 keV: tunnelling, 14× below the top.
let = gamow_peak;
println!;
// Bosch & Hale's reaction rate there.
assert!;
Example: the pinch and its gravitational twin
use ;
use ;
// The equation that holds a 1 MA Z-pinch together is the one that holds a molecular-cloud
// filament together, with gravity in place of magnetism (Bennett 1934, Ostriker 1964).
let cloud = ostriker_line_mass * PARSEC / SOLAR_MASS; // 16.6 solar masses per parsec
let pinch = bennett_line_density * 3.3436e-27; // deuterium at 2 keV, kg/m
assert!;
// In the pinch, magnetism beats the plasma's own gravity by 5.5×10²⁷.
assert!;
What is inside
| Module | What it computes | Key sources |
|---|---|---|
fusion |
Coulomb barrier, Sommerfeld and Gamow factors, Gamow peak, Bosch–Hale reactivities and cross sections (D–T, D–D, D–³He), p–¹¹B (Nevins–Swain, Tentori–Belloni), Lawson, screening (first-order and exact), Salpeter, muon catalysis, Lane–Emden, and the low-energy fusion checks | Bosch & Hale 1992 (implementation notes); Wurzel & Hsu 2022; Tentori & Belloni 2023 |
pinch |
Bennett temperature and line density, Pease–Braginskii, Lee's peak current and yield, snowplow speed, cyclotron energy, the Ostriker filament | Klír 2005; Lee 2009; Ostriker 1964 (ApJ 140, 1056) |
relaxation |
Bessel-function model, spheromak eigenvalues, Taylor-state energy, FRC beta and s-parameter, Lundquist number, Sweet–Parker and plasmoid reconnection, the virial cap on a free plasmoid | Taylor 1986; Tuszewski 1988; Loureiro et al. 2007 |
aneutronic |
Q-values, D–³He neutron fraction, relativistic bremsstrahlung, synchrotron, the p–¹¹B fusion-to-bremsstrahlung ratio | Putvinski, Ryutov & Yushmanov 2019 (Nucl. Fusion 59, 076018) |
collisions |
Spitzer's resistivity across and along the field, shared by the pinch and reconnection calculators, its coefficient checked against Braginskii's m_e/(n_e e² τ_e) |
NRL Plasma Formulary; Braginskii 1965 |
discharge |
Gas discharges and the thin gas around them: Paschen breakdown and its minimum with air's Townsend constants, the mean free path, Peek's corona onset, the floating potential in a glow, ion mobility, gas density and molecular speed, and slip-corrected drag on a sphere moving or turning at any Knudsen number: whether a high-voltage rig "in vacuum" is free of ions, and how long a body in it keeps swinging | Raizer, Gas Discharge Physics (1991), table 4.1; Peek 1929; Hirschfelder, Curtiss & Bird 1954; Davies 1945; Lieberman & Lichtenberg |
tokamak |
The design scalings a tokamak is checked against: edge safety factor and the kink limit, Greenwald density, Troyon beta and IPB98(y,2) confinement, with ITER and SPARC | ITER Physics Basis (Nucl. Fusion 39, 1999); Creely et al. 2020 (J. Plasma Phys., SPARC) |
conversion |
N-stage direct-collector efficiency, engineering gain of magnetic and inertial plants, pulsed inductive breakeven, laser p–¹¹B gain | Moir & Barr 1973 (Nucl. Fusion 13, 35); Margarone et al. 2020 |
The research behind it, with every claim's status, is in the reports on the Coulomb barrier and the Schwinger limit and on Z-pinches, plasmoids and aneutronic fusion.
Applications
- Judging a design point.
tokamakchecks a machine against the safety-factor, density, beta and confinement limits it must respect;examples/sparc.rsruns ITER and SPARC. - Reading a shot.
examples/triple_products.rsplaces published results against the Lawson requirement at their own temperature, andexamples/fusion_yields.rsturns a yield into the reactions and fuel behind it. - Choosing a fuel.
aneutronicandconversionweigh p–¹¹B and D–³He against bremsstrahlung and set out what direct conversion returns without a steam cycle. - Pinches and self-organisation.
pinchandrelaxationgive the equilibria, scalings and reconnection rates, with the gravitational twin of the Bennett relation alongside.
How it is checked
- Bosch–Hale: all of UWFDM-1268's Table 6 (D–T, both D–D branches, D–³He at 1, 10 and 100 keV) within 0.4%; the D–T cross-section peak (5.07 b); and the Maxwellian average of the cross section against the reactivity fit.
- p–¹¹B: the published Nevins–Swain and Tentori–Belloni tables, and their 30% and 50% gaps.
- Lawson: Wurzel & Hsu's 2.97×10²¹ keV s m⁻³ at 14 keV and the 4.3 keV ignition temperature.
- Pinches: Klír's 3.12 keV Bennett coefficient, the 1.4 MA Pease–Braginskii current, and Lee's Table I peak currents within 1.5%.
- Plasmoids: Ji & Daughton's Lundquist numbers and Bhattacharjee et al.'s rates.
- Aneutronic power: NRL's bremsstrahlung limit and Putvinski's synchrotron ratios.
- Laser shots: Margarone's and the PALS shots' energy returns.
One of eight crates in physica:
physica (all of them, plus cross-domain analogies) ·
metrology (constants) ·
geopotential (the gravity field) ·
gravimetry (missions and GRACE) ·
gravitational (waves) ·
gravitics (frontier gravity) ·
magnetics (magnetism and MHD) ·
plasmoid (fusion plasma).