delta ray

American

noun

Physics.

a low-energy electron emitted by a substance after bombardment by higher-energy particles, as alpha particles.

delta ray British

noun

a particle, esp an electron, ejected from matter by ionizing radiation

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of delta ray

First recorded in 1905–10

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023