Terms starting with N
32 terms · page 2 of 2
Nuclear Fusion
Nuclear & Particle Physics
MeV (Mega-electronvolts)
A nuclear reaction in which two light atomic nuclei collide and combine to form a single heavier nucleus, releasing vast amounts of energy.
²₁H + ³₁H → ⁴₂He + ¹₀n + 17.6 MeV
Nuclear Reactor
Nuclear & Particle Physics
MWth or MWe (Power Capacity)
An engineered facility in which a controlled self-sustaining nuclear chain reaction is maintained to generate thermal energy for electrical power generation.
Multiplication Factor k = Neutrons in generation (i+1) / Neutrons in generation i
Nuclear Shell Model
Nuclear & Particle Physics
Quantized Energy Shells
A quantum nuclear model describing nuclear energy levels in terms of individual nucleons moving inside a central potential well with strong spin-orbit coupling.
Magic Numbers: 2, 8, 20, 28, 50, 82, 126
Nuclear Stability
Nuclear & Particle Physics
Dimensionless N/Z Ratio
A measure of a nuclide's resistance to spontaneous radioactive decay, determined by the balance between nuclear strong attraction and proton Coulomb repulsion.
N/Z ≈ 1 (for light nuclei), N/Z ≈ 1.5 (for heavy nuclei)
Null Vector
Foundations of Physics
Various
A vector having zero magnitude and an arbitrary or indeterminate direction.
0 = 0i + 0j + 0k
Numerical Linear Algebra
Mathematical & Computational Physics
Matrix Factorization Algorithms
The subfield of numerical analysis studying algorithms for performing matrix operations efficiently and accurately on digital computers.
LU: A = L U, QR: A = Q R, SVD: A = U Σ V^T
Numerical Stability
Mathematical & Computational Physics
Algorithm Stability Property
The property of a numerical algorithm ensuring that errors introduced during computation do not magnify uncontrollably over successive time steps.
Von Neumann Stability Analysis: |G(k, Δt)| ≤ 1
Nutation
Geophysics & Environmental Physics
Arcseconds (17.2″ in longitude, 9.2″ in obliquity)
Small periodic nodding oscillations superimposed upon Earth's long-term rotational axis precession.
Principal Nutation Period T = 18.6 years, Amplitude = 9.2″