delta ray

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

* * *

      in physics, any atomic electron that has acquired sufficient energy by recoiling from a charged particle passing through matter to force, in turn, some dozens of electrons out of other atoms along its own trajectory.

      The charged particle giving rise to delta rays generally is relatively large, such as an alpha particle (composed of two protons and two neutrons), but may also be a high-speed electron. This particle, as it slows down in matter, forces thousands of electrons out of atoms by ionization, producing a wake of electrons and positive ions (electron-deficient atoms) that can be detected. The detached electrons are usually of such low energy that they cannot produce further ionization. But periodically, a relatively large amount of energy is transferred to an electron by a nearly head-on collision along the path of the primary ionizing particle. These are the energetic electrons that cause secondary ionization and are referred to as delta rays. On a developed photographic emulsion, in which strongly ionizing particles have left dense tracks, delta rays appear as thin wavy spurs or branches. The term delta ray, first used by the British physicist J.J. Thomson, is sometimes extended to any recoil particle that causes secondary ionization.

* * *

Universalium. 2010.

Поможем решить контрольную работу

Look at other dictionaries:

  • delta ray — n. high energy electrons ejected from atoms by primary ionizing particles passing through matter …   English World dictionary

  • Delta ray — Contents 1 Characteristics 2 Delta rays in particle accelerators 3 See also …   Wikipedia

  • delta ray — noun an electron ejected from matter by ionizing radiation • Hypernyms: ↑electron, ↑negatron * * * noun : an electron ejected by an ionizing particle (as an alpha particle) in its passage through matter * * * Physics. a low energy electron… …   Useful english dictionary

  • delta ray — del′ta ray n. phs a low energy electron emitted by a substance after bombardment by higher energy particles, as alpha particles • Etymology: 1905–10 …   From formal English to slang

  • delta ray — /ˈdɛltə reɪ/ (say deltuh ray) noun Physics slow electrons knocked out of atoms by fast moving ionised particles …   Australian-English dictionary

  • delta ray — noun Date: 1908 an electron ejected by an ionizing particle in its passage through matter …   New Collegiate Dictionary

  • delta ray — noun a) An electron ejected by recoil when a rapidly moving alpha particle or other charged particle passes through matter. b) A secondary ionizing particle ejected by recoil when a primary particle passes through matter …   Wiktionary

  • Delta, Utah —   City   …   Wikipedia

  • Delta smelt — Delta smelt, Hypomesus transpacificus Conservation status …   Wikipedia

  • Delta High School (Clarksburg, California) — Delta High School Magnet School No School District River Delta Unified School District School Colors Black and Gold …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”