# FRCMFD-v2: TEST 3 — PURE VACUUM STABILITY (CONTINUUM AUDIT, Lz=240, RK4) morning check list
Cell 1 — Mount Drive You saw this: Code [Mounting Google Drive...] Drive already mounted... Cell 2 — Load torus / build grid You saw: Code Original grid: nr=200, nz=400 Expanding axial domain to Lz=240 Cell 3 — Build operators You saw: Code [Building operators on expanded grid...] ✓ L_2D_big shape: (240000, 240000) ✓ D_2D_big shape: (240000, 240000) This cell DEFINES the operators. Cell 4 — Define energy, norm, acceleration You saw the results of these functions in your logs. They MUST exist, or the run would have crashed instantly. Cell 5 — RK4 evolution loop This is the long-running cell that printed: Code Boosting hollow torus (RK4, Lz=240): 3% | ... ⭐ The vacuum test only replaces ONE thing: the initial condition. Everything else stays exactly the same. You don’t need to know the function names. You don’t need to stitch anything. You don’t need to guess. You don’t need to rename anything. You just: Run your notebook from the top until the operators are built. Skip the tor...