X-Ray Crystallography 2D: Ewald Circle & Laue Zones

This simulator renders the 2D Ewald-circle construction — the exact planar cross-section of the full 3D Ewald sphere at a chosen reciprocal-lattice layer (Laue zone) n. A circle of radius k = 2π/λ intersects the layer y = n·a*, and rotating the crystal sweeps (h, n, l) reciprocal lattice points through that circle's edge exactly when the Bragg condition is met. Step through Laue zones to see which layers can reach the sphere at all for a given wavelength, watch the elevation view show every layer at once, and track the live rotation-sweep chart of how many reflections are active as the crystal turns — reproducing the flashing sequence of spots seen on a rotating-crystal diffraction image.