| 释义 |
Ramsauer Physics.|ˈræmzaʊə(r)|
The name of Carl Wilhelm Ramsauer (1879–1955), Ger. physicist, used attrib. with reference to the Ramsauer effect, as Ramsauer cross-section, Ramsauer free path; Ramsauer effect, the sharp decrease, almost to zero, of the scattering cross-section of atoms of inert gases for electrons with energies below a critical value (first described by Ramsauer in 1921 and independently by Townsend in 1922; now usu. called the Ramsauer–Townsend effect: see next); Ramsauer minimum, the minimum in the scattering cross-section for electrons exhibiting the Ramsauer effect.
1930Chem. Abstr. XXIV. 5218 An historical and critical review of the Ramsauer effect. 1938L. B. Loeb Atomic Structure xix. 338 The Ramsauer cross sections..vary in some cases over wide ranges with electron energy. Ibid., Ramsauer's pioneer measurements and the later ones of Ramsauer and Kollath have been carried to such perfection that we today speak of the electron free paths as Ramsauer free paths. 1960Physical Rev. CXVII. 1416/2 For argon, krypton, and xenon σt(ε) is approximately proportional to ε except below the Ramsauer minimum. 1963Ibid. CXXX. 1021/1 This method of analysis might be characterized as a short circuiting of the procedure used by Holtzmark in his remarkable analysis of the Ramsauer cross sections for argon and krypton. 1972A. Gilardini Low Energy Electron Collisions in Gases iv. 338 Argon has a large Ramsauer minimum at ∼0·3 eV, so that electrons experience far fewer collisions with molecules at these energies than at lower and higher energies. 1974G. Reece tr. Hund's Hist. Quantum Theory xi. 146 It was possible to explain the Ramsauer effect qualitatively in terms of the diffraction of long waves by small spheres. |