Nuclear Cross-Section
Convert between different units of nuclear cross-section used in nuclear physics, particle physics, and nuclear engineering
Nuclear Cross-Section Converter
Convert between different units of nuclear cross-section used in nuclear physics, particle physics, and nuclear engineering
Conversion Result
Fun Facts
About Nuclear Cross-Section
Explore nuclear cross-section units from nuclear physics, particle physics, and nuclear engineering
Historical Context
The concept of nuclear cross-section emerged in the early days of nuclear physics in the 1930s as a way to quantify the probability of nuclear interactions. The barn unit (10^-28 m²) was introduced during the Manhattan Project in the 1940s as a code name for the cross-sectional area of uranium nuclei, which were considered 'as big as a barn' compared to other nuclei. The name stuck and became standard terminology in nuclear physics. As particle accelerators advanced, smaller cross-sections needed to be measured, leading to the introduction of millibarn, microbarn, and eventually femtobarn and attobarn units for high-energy physics experiments. The cross-section concept has been fundamental to understanding nuclear reactions, from nuclear power to stellar nucleosynthesis.
Modern Standards
Today, the barn (b) remains the standard unit for nuclear cross-sections, representing 10^-28 square meters. In nuclear engineering and reactor physics, cross-sections are typically in the barn to millibarn range for common reactions. High-energy physics at particle colliders like the Large Hadron Collider (LHC) deals with much smaller probabilities, using picobarns, femtobarns, and attobarns. The integrated luminosity of collider experiments is often quoted in inverse femtobarns (fb^-1), which, when multiplied by a cross-section in femtobarns, gives the expected number of events. While the barn is not an SI unit, it is accepted for use with the SI system due to its widespread adoption in nuclear and particle physics. Modern nuclear data libraries compile evaluated cross-sections for thousands of nuclear reactions across wide energy ranges, essential for applications from nuclear medicine to space radiation shielding.
Did you know?
Select a unit to see interesting facts about it.
Conversion Reference
Quick reference for common nuclear cross-section conversions