Convert Square Micrometer (µm²) to Barn (b (area)) instantly.
About these units
Square Micrometer (µm²)
A square micrometer, also called a square micron, equals 10⁻¹² square meters. It is a fundamental unit in microbiology, nanotechnology, semiconductor physics, and materials characterization. Cells, organelles, thin films, and laser spot sizes are frequently measured in µm². In semiconductor fabrication, transistor gates, nanoscale features, and photolithographic patterns often have areas measured at this scale. At such dimensions, quantum effects, crystal lattice structures, and electron mobility become important, making µm² not just a geometric unit but a bridge to fundamental physical behavior at microscopic scales.
Barn (b (area))
The barn is an area unit used almost exclusively in nuclear and particle physics, equal to 10⁻²⁸ square meters. Despite its incredibly tiny size, the barn emerged from humorous origins: early nuclear physicists joked that certain atomic nuclei were "as big as a barn" compared to the particles trying to hit them. The barn quantifies interaction cross-sections—essentially probabilities of particles colliding or interacting with nuclei. Because fundamental forces operate at extremely small scales, typical cross-section values lie in the microbarn, nanobarn, or picobarn range. The barn is essential for describing reaction rates in particle accelerators, nuclear reactors, and astrophysical processes such as stellar fusion.