| 释义 |
back scattering Physics.
[back adv.]
The scattering of radiation in a reverse direction from an irradiated substance.
1940Physical Rev. LVII. 29/2 (heading) Disregard of back scattering. It is frequently assumed that all electrons are scattered only in the forward direction. 1946Ibid. LXX. 602 The backscattering of d-d neutrons was investigated for several materials. 1958New Scientist 2 Jan. 23/1 Heavyweight atoms like those of lead give a bigger ‘backscattering’ than lightweight atoms such as those of aluminium. 1960Gloss. Atomic Terms (A.E.A.) 5 Back scattering, the emergence of radiation from that surface of a material through which it entered, due to its collision with and reflection from atoms in the material.
Hence (as a back-formation) back-scatter v. trans.; back scatter, n. (a) back scattering; (b) the radiation scattered in this way; hence in Telecommunications (see quot. 1960); also attrib.
1957Gloss. Terms Nucl. Sci. (Nat. Res. Council, U.S.) 16/1 Back scatter. 1958New Scientist 2 Jan. 23/1 The beta ray source is shielded so that only radiation backscattered by the sample can enter the counter. 1959Manchester Guardian 11 Aug. 7/4 The United States Navy's successful experiments with ionospheric ‘back-scatter radar’, capable of detecting a nuclear explosion from thousands of miles away. 1960Gloss. Terms Telecomm. (B.S.I.) 168 A signal received by back scattering is often referred to as back scatter. 1962Gloss. Terms Nuclear Sci. (B.S.I.) 12 Back scatter, the emergence of radiation from that surface of a material through which it entered... The term is also used for the actual back-scattered radiation. |