Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
barn
Introduction References & Edit History Related Topics
Quick Facts
Related Topics:
cross section
See all related content
Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites

barn

measurement
Written and fact-checked by
Britannica Editors
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
Britannica Editors
History

barn, unit of area used to measure the reaction cross section (generally different from the geometric cross section) of atomic nuclei and subatomic particles in the study of their interactions with other nuclei or particles. It is equal to 10βˆ’24 square cm. The name, coined by U.S. scientists, is derived from the proverbial phrase β€œside of a barn,” something easy to hit. See cross section.

This article was most recently revised and updated by William L. Hosch.