T1 Relaxation & the BPP Minimum: Molecular Tumbling

Every nucleus you flip with an RF pulse eventually relaxes back to thermal equilibrium along the static field — but how fast depends on how the molecules around it are tumbling. This simulator renders the Bloembergen-Purcell-Pound (BPP) picture of spin-lattice relaxation directly: a lattice of small nuclear dipoles reorients randomly at a correlation time τ_c you control, producing a fluctuating local field whose power at the Larmor frequency ω₀ sets the spin-lattice relaxation rate 1/T₁. Sweep τ_c or the static field B₀ and watch T₁ trace the classic V-shaped minimum where ω₀τ_c ≈ 1 — then fire an inversion pulse and watch the bulk magnetization arrow actually recover at the T₁ your settings predict, live readouts and a τ_c-vs-T₁ chart tracking every step.