Terms starting with U
3 terms
Unit Cell
Condensed Matter & Materials Physics
ų or nm³ (Unit Cell Volume)
The smallest repeating structural unit of a crystal lattice that generates the entire 3D crystal structure through simple translational repetition.
V_cell = a · (b × c)
Unit Vector
Foundations of Physics
Dimensionless
A dimensionless vector with a magnitude of exactly one, used exclusively to specify a direction in space.
û = u / |u|
Upper & Lower Hybrid Resonances
Plasma Physics
rad/s (Resonance Frequencies)
Characteristic wave resonance frequencies in magnetized plasmas where wave group velocity vanishes and electromagnetic energy couples efficiently into plasma heating.
Upper: ω_UH = √(ω_pe² + ω_ce²); Lower: 1 / ω_LH² = 1 / (ω_ci² + ω_pi²) + 1 / (ω_ce ω_ci)