Extreme Ultra—violet Spectra

摘要: Extreme ultra-violet spectra, to 136 A, of twenty light elements, H Cu.—Using the vacuum apparatus and explosive spark previously described, many plates have been made with a great variety electrodes. By measuring comparing thirty these, over 800 lines between A 1862 identified as belonging one or other elements studied. For H(1) only two lines, members Lyman series, were found; for He(2), Li(3) none, though carefully looked for; Be(4) doubtful weak line; Na(11) strong line λ372.3 λ376.6; B(5), C(6), N(7), O(8), F(9), Mg(12), Al(13), Si(14), P(15), S(16), Cl(17), K(19), Ca(20), Cr(24) Cu(29) from 9 160 each, all given in Tables. The strongest each are L series form progression like Moseley's x-ray lines: Li (red), Be 3131.19, B 2066.2, C 1335.0, N 1085.2, O 834.0, F 656.4, Na 372.3, Mg 231.6, Al 162.4. These mainly doublets, separation increasing regularly atomic number. M spectra also extend shorter wave-lengths higher number, reaching about 155 Cu, but on account complexity few identified. Other are: 2 diffuse sharp due Mg+ Mg(II), 5 Al+ Al++ Al(III), 11 Si(IV) probably first terms principal P(V). Interpretation Bohr theory. use Kossel equation connection available data it is shown that Na, 372.3 corresponds an electron jump shell L(I); Mg, 320.9, 323.2 231.6 correspond M(I)→L(II), M(I)→L(III) M(III)→L(I); Al, 162.4, 200.0, 230.8, 186.9 may jumps 3 shell; Ca, 655.9 669.6 N(I)→M(II) N(I)→M(III). interpretations give values constants levels atoms follows: L(I), ν/R=2.826; L(I) 4.298, L(II) 3.402, L(III) 3.381; 6.045, 5.008. square roots these linear functions Ca M(II), ν/R=1. 839, M(III) 1.810. From difference L(II)—L(III) screening constant comes out 3.1; M(III)—M(II) 7. results good agreement data. Ionization produced by vacuum.—The spectrum generally emitted stripped atoms, no valence electrons left, Na(I), Si(IV), P(V), etc.