schmidt_2007

J. W. Schmidt, R. M. Gavioso, E. F. May and M. R. Moldover, “Polarizability of Helium and Gas Metrology”, Phys. Rev. Lett. 98, 254504 (2007)

Source record · Catalogue · Review register

DOI: 10.1103/PhysRevLett.98.254504

Source kind: measurement

Recorded technique: Quasispherical microwave cavity resonator (maraging steel, copper plated, radius about 4.82 cm) filled with helium (99.9999 %, trapped and gettered) at 0.1-6.3 MPa near 273.16 K: n^2 from the frequencies of the TM11, TE11, TM12 and TE12 triplets (2.7-7.6 GHz) in vacuum and under pressure, corrected for the cavity’s isothermal compressibility kappa_T (resonance ultrasound spectroscopy) and the field penetration (Eq. 5); pressure from a calibrated piston gauge; n^2(rho) fitted by a quadratic in density whose linear coefficient is 3(A_eps + A_mu) (pp. 1-3).

Materials in structured entries: He

Dataset quantities: molar_refractivity

Contents: 2 datasets; 0 formulas.

Curation notes

The result (abstract, pp. 1 and 3): ‘A_eps,meas = 0.517 253 5 (47) cm3 mol-1, which is equivalent to (A_eps,meas - A_eps,theory)/A_eps = (-1.8 +- 9.1) x 1e-6’, one standard uncertainty (‘The uncertainties are one standard uncertainty’, p. 1); 9.1 ppm combines the fit’s 1.8 ppm with the Table I components (kappa_T 4.8 ppm, p_lab 4.3 ppm, R 1.8 ppm, ...). The quantity measured is A_eps + A_mu (zero-density limit, 273.16 K); A_mu = 4 pi chi_0/3 = -0.000 008 03 (17) cm^3/mol from Bruch and Weinhold (2000) was subtracted (Table I), so the measured A_eps + A_mu is 0.5172455(47) (puchalski_2016 Table X, which uses -0.0000079224 and prints this sum). The theoretical A_eps compared is Lach et al.’s 0.517 254 19 (10). The glyphs of the parentheses are unmapped in the library’s text (validation warnings, pp. 1-4); the value was checked on the pdf text and against puchalski_2016’s reproduction.

Frequency: the resonances are at 2.7-7.6 GHz (vacuum wavelengths 3.9-11 cm); ‘the experimental result for A_eps was independent of the mode’ and A_eps(f)/A_eps(0) - 1 = 22.6e-14 (f/GHz)^2 (Stone and Stejskal, p. 3), so the value is the static limit to 1e-11: stored at wavelength inf.

Also in Table I (inputs, not extracted): B_rho = 11.9301(39) cm^3/mol (Hurly and Mehl 2007), dielectric virial b = -0.098(04) cm^3/mol (Rizzo et al. 2002; B_eps = A_eps b in the package’s convention, not printed), c = -1.34(36) cm^6/mol^2 (Heller and Gelbart), C_rho = 112.7(20) cm^6/mol^2 and D_rho = 820(70) cm^9/mol^3 (McLinden and Loesch-Will), R = 8.314 472 (15), kappa_T = 6.0370(46)e-12 /Pa. Eq. (4) lacks a factor 2 in front of A_eps^2 b rho^2 (puchalski_2016 p. 12). Alternative reading: R = 8.314 487(76) J/(mol K) if theory is accepted (p. 4).

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

Datasets

schmidt_2007/molar_polarizability

{
  "id": "molar_polarizability",
  "material": "He",
  "table": "text",
  "quantity": "molar_refractivity",
  "unit": "cm3/mol",
  "abscissa_unit": "angstrom",
  "wavelength_medium": "vacuum",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "1 sigma"
  }
}

1 inline points in the source record.

pp. 1 and 3: measured A_eps = 0.517 253 5 (47) cm3/mol at 273.16 K, zero-density limit, magnetic term A_mu = -0.00000803 cm3/mol subtracted; microwave (2.7-7.6 GHz), stored as static. Row id is the temperature.

schmidt_2007/lach_2004

{
  "id": "lach_2004",
  "material": "He",
  "file": "He/schmidt_2007__lach_2004.csv",
  "table": "tbl_db1498b084c8",
  "quantity": "molar_refractivity",
  "unit": "cm3/mol",
  "abscissa_unit": "angstrom",
  "wavelength_medium": "vacuum",
  "use": "reproduced",
  "reproduced_from": [
    "lach_2004"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  }
}

Table I: the theoretical A_eps 0.517 254 19 (10) of Lach et al. (2004), the value this measurement is compared with.

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.