laporte_1981

P. Laporte, J. L. Subtil, M. Bon and H. Damany, “Vacuum UV high-performance spectrophotometric setup for use in the 105-200-nm wavelength range”, Appl. Opt. 20, 2133 (1981)

Source record · Catalogue · Review register

DOI: 10.1364/ao.20.002133

Source kind: measurement

Recorded technique: Instrument paper (Saint-Etienne): a double-beam VUV spectrophotometer for reflectance and transmittance of gases, liquids and solids in closed cells, 105-200 nm, -200 to +100 degrees C, 0-150 bar. A dc H2/D2 capillary discharge (conical, air-cooled fused-silica capillary, LiF window or windowless, 20 mA to 1.5 A), a 1 m holographic grating monochromator (2400 grooves/mm, 0.02 nm instrumental width), the reference beam from the front face of a slightly prismatic (5 degree) LiF or MgF2 cell window and the signal from its inner face against the sample; sodium salicylate and two EMI 9804QA photomultipliers, a ratiometer and a PDP 11-03 computer. Reflectance R(lambda) relative to the empty cell’s R_0 = (n’ - 1)^2/(n’ + 1)^2, Eqs. (1)-(7); transmittance gives the absorption index k, Eq. (8).

Materials in structured entries: None recorded.

Dataset quantities: None recorded.

Contents: 0 datasets; 0 formulas.

Curation notes

Journal pages 2133-2138 = PDF pages 1-6; the PDF is a scan. Identity checked against the first page. Cited for method only: no dataset. The instrument is the one used for Laporte and coworkers’ later reflectance spectra of dense and condensed xenon (its Ref. 9, Phys. Rev. Lett. 45, 2138 (1980), not in the library).

PERFORMANCE (pp. 4-6): the ratio stable to 0.07 % per day at 25 degrees C; drift up to 6 %/h at 77 K from condensation on the cold window, 0.35 %/h with the additional room- temperature LiF window; the ratio linear to 2 % over three decades of illumination; dark current 4e-11 A; reflectance as low as 0.05 % observed.

THE XENON TEST OF STRAY LIGHT (p. 5). At 190 nm the paper takes n_0 = 1.000995 for Xe at 0 degrees C and 760 Torr (from its Refs. 11 and 12, Chashchina and Shreider 1969 and Abjean et al. 1971; which one is not said) and n’ = 1.430 for the MgF2 window, and finds from ‘the Lorentz-Lorenz law’ that n = n’ at N/N_0 = 389; a reflectance minimum of 0.05 % was observed at N/N_0 = 383 (temperature not stated). The formula is printed L = (n^2 - 1)/(n^2 + 1) x N_0/N (page image checked): a misprint for (n^2 - 1)/(n^2 + 2), since the paper’s 389 follows only from the latter (389.5; the printed form gives 345) (TC-715). Against the package: fit/Xe gives n - 1 = 996.9e-6 at 190 nm (real gas, 0 degrees C, 1 atm), 0.19 % above the quoted value (abjean_1971’s measurements interpolated give about 998e-6). With fit/Xe’s molar refractivity (A_R = 14.790 cm^3/mol at 190 nm) and the refractivity virial coefficient the package uses (Burns et al.’s 25.5 cm^6/mol^2, 633 nm), n = 1.430 is reached at 377.7 amagat (1 amagat = 4.4927e-5 mol/cm^3, Laporte et al. 1975), against 388.8 without the pair term: the observed 383 lies between. The test is not quantitative for B_R: 0.001 in MgF2’s index (whose axis and source the paper does not state beyond its Ref. 7) moves the crossing by 0.5 %, and the density scale and temperature are not given.

NOT TRANSCRIBED: Figs. 4 and 5, the reflectance of the liquid (165 K, 29.4 bar) and solid (120 K) xenon-MgF2 interface with the exciton peaks (condensed phases, outside the package’s gases; raster).

Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets

No datasets are recorded.

Formulas

No formulas are recorded.

Corrections

No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.