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Crookes dark space

noun Physics.
  1. the dark space between the cathode glow and the negative glow in a vacuum tube, occurring when the pressure is low.

Origin of Crookes dark space

First recorded in 1890–95; after Sir W. Crookes
Also called Crookes space.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for crookes space

Crookes space

noun
  1. a dark region near the cathode in some low-pressure gas-discharge tubesAlso called: Crookes dark space
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