shelton_1992#

D. P. Shelton and E. A. Donley, Chem. Phys. Lett. 195, 591 (1992)

Source record · Catalogue · Review register

Source kind: measurement

Recorded technique: ESHG with periodic phase matching relative to He, as in shelton_1990 and Shelton & Lu 1988: argon-ion laser (514.5, 488.0 nm), 2-3 W at the sample, confocal parameter 20 cm, beam polarised parallel to the static field; electrode array with 2.69 mm spacing and 150 pairs (Ne phase match at 29 and 24 atm, 26 C), and a coarser array (5.08 mm, 82 pairs) at half the density; sample and reference in 2-3 coupled triplets; 99.999 % gases; pressures with a Paroscientific 1003K gauge (+-0.02 atm) (p. 2).

Materials in structured entries: He, Ne

Dataset quantities: hyperpolarizability, hyperpolarizability_ratio, phase_match_density_ratio

Contents: 12 datasets; 4 formulas.

Curation notes#

The corrected neon hyperpolarizability: ‘the anomalous hyperpolarizability dispersion previously observed for neon is spurious’ (abstract). The earlier visible data (Shelton & Lu 1988) are discarded (electrical breakdown in neon went unnoticed, p. 3); the new visible points and shelton_1990’s infrared points give gamma_0 = 108 +- 2 au and A = 2.47 au (omega_L^2 in au), against shelton_1990’s 119 au and negative A. Supersedes shelton_1990’s Ne fit (table4_Ne) and shelton_1989’s anomaly.

Definitions: gamma is the ESHG hyperpolarizability gamma(-2w; w, w, 0), the same quantity and convention as shelton_1990 (Taylor series; shelton_1994 reproduces this fit), per atom, in au with the Ne reduced-mass factors (1 au = 219469 cm^-1 for omega, 6.23656e-65 C^4 m^4 J^-3 for gamma, p. 3). Dispersion: gamma = gamma_0 (1 + A omega_L^2 + B omega_L^4), omega_L^2 = 6 omega^2 for ESHG, omega and gamma in au (Table 2 caption). Calibration: Bishop & Pipin’s ab initio gamma_He (bishop_1989) through shelton_1990’s fit; ‘note that table 2 of ref. [1], which gives the fit coefficients, has a misprint: 10^-31 in the last line should be 10^-32’ (p. 3; recorded on shelton_1990’s formula table2_He_si). No separation of parts is needed (atom: electronic). Pair interactions: theory predicts gamma_Ne/gamma_He overestimated by 0.3 % at the highest density; the half-density measurement bounds the pair contribution below about +-1 %; the tabulated gamma_Ne include a 0.0 +- 0.3 % correction (p. 4).

Other experiments (Table 1 caption): ‘The only other measurements of gamma_Ne are from one dc Kerr effect experiment and two third harmonic generation experiments (error bars +-8%-17%, see ref. [2] for discussion)’. The dc Kerr value and the ab initio best estimates are recorded from the text (p. 4-5). A comparison with He: ‘The dispersion is only slightly larger for gamma_Ne than for gamma_He (A = 2.5 au versus A = 2.191 au)’ (p. 4). Figure 1 (the dispersion plot) is not digitised. The library’s validation shows no findings; the two tables’ CSV cells agree with their images.

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

Datasets#

shelton_1992/gamma_present#

{
  "id": "gamma_present",
  "material": "Ne",
  "file": "Ne/shelton_1992__gamma_present.csv",
  "table": "tbl_9856decaf635",
  "quantity": "hyperpolarizability",
  "unit": "au",
  "abscissa_unit": "cm-1",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "process": "eshg",
    "convention": "T",
    "part": "electronic"
  }
}

Table 1 rows c) (present work), argon-ion laser at 514.5 and 488.0 nm (air; abscissa the vacuum wavenumber). gamma_Ne in au ‘when reduced mass corrections for neon are incorporated into the conversion factors’: 1 au = 219469 cm^-1 for omega and 1 au = 6.23656e-65 C^4 m^4 J^-3 for gamma (p. 3). Obtained from gamma_Ne/gamma_He with Bishop & Pipin’s gamma_He (bishop_1989) through the fit of shelton_1990 Table II (whose C misprint the paper notes). ‘The results for gamma_Ne from the present experiments, given in table 1, include an estimated pair interaction correction of 0.0 +- 0.3%’ (p. 4). Error budget for gamma_Ne/gamma_He: ‘+-0.05%-0.25% for reproducibility and +-0.1% from the density determinations’ (p. 2); no allowance for the He calibration (thought better than 0.1 %).

shelton_1992/ratio_present#

{
  "id": "ratio_present",
  "material": "Ne",
  "file": "Ne/shelton_1992__ratio_present.csv",
  "table": "tbl_9856decaf635",
  "quantity": "hyperpolarizability_ratio",
  "unit": "1",
  "abscissa_unit": "cm-1",
  "use": "check",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "reference_material": "He",
    "process": "eshg",
    "convention": "T",
    "part": "electronic"
  }
}

Table 1 rows c): gamma_Ne/gamma_He as measured (the raw ESHG ratio behind gamma_present, so not independent of it). Phase match for Ne at 29 and 24 atm (26 C) for 514.5 and 488.0 nm (p. 2). Pair interaction effects are not in the error bars of the ratio (p. 2).

shelton_1992/gamma_infrared#

{
  "id": "gamma_infrared",
  "material": "Ne",
  "file": "Ne/shelton_1992__gamma_infrared.csv",
  "table": "tbl_9856decaf635",
  "quantity": "hyperpolarizability",
  "unit": "au",
  "abscissa_unit": "cm-1",
  "use": "reproduced",
  "reproduced_from": [
    "shelton_1990",
    "shelton_1989"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "process": "eshg",
    "convention": "T",
    "part": "electronic"
  }
}

Table 1 rows d) (Refs. [1, 2] = shelton_1990, shelton_1989): the 1319 and 1064 nm ratios 2.534 and 2.487 of shelton_1990 Table I re-expressed in au with the Ne reduced-mass factor (shelton_1990 Table III: 6.925e-63 and 6.855e-63 C^4 m^4 J^-3 = 111.04 and 109.92 au with 6.23656e-65). Included in the new fit, but ‘the scatter about the fitted curve is greater than the stated error bars for the two infrared measurements’ (p. 4).

shelton_1992/gamma_finn_ward#

{
  "id": "gamma_finn_ward",
  "material": "Ne",
  "file": "Ne/shelton_1992__gamma_finn_ward.csv",
  "table": "tbl_9856decaf635",
  "quantity": "hyperpolarizability",
  "unit": "au",
  "abscissa_unit": "cm-1",
  "use": "reproduced",
  "reproduced_from": [
    "R. S. Finn and J. F. Ward, Phys. Rev. Lett. 26, 285 (1971)"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "process": "eshg",
    "convention": "T",
    "part": "electronic"
  }
}

Table 1 row e) (Ref. [11], Finn & Ward 1971), ruby laser, rescaled to Bishop & Pipin’s He; not in the fit (‘the fifth value has large uncertainty’, caption).

shelton_1992/gamma_shelton_lu#

{
  "id": "gamma_shelton_lu",
  "material": "Ne",
  "file": "Ne/shelton_1992__gamma_shelton_lu.csv",
  "table": "tbl_9856decaf635",
  "quantity": "hyperpolarizability",
  "unit": "au",
  "abscissa_unit": "cm-1",
  "use": "excluded",
  "reproduced_from": [
    "D. P. Shelton and Z. Lu, Phys. Rev. A 37, 3813 (1988)"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "process": "eshg",
    "convention": "T",
    "part": "electronic"
  }
}

Table 1 rows f) (Ref. [9], Shelton & Lu 1988). SPURIOUS: ‘the signal for helium was too large’ because of an unnoticed electrical breakdown in neon (‘a steady, electrically quiet discharge’), so ‘the last three measurements of gamma_Ne/gamma_He given in table 1 should be discarded’ (p. 3). Their phase-match density ratios agree with the new ones, so the samples were not contaminated. These are the data behind the anomalous Ne dispersion of shelton_1989 and shelton_1990 (and essentially the same values as shelton_1990’s excluded table3_Ne_literature: 6.402, 6.816, 7.141e-63 = 102.65, 109.29, 114.50 au). Row 594.5 nm (16817 cm^-1; shelton_1990 prints 594.4).

shelton_1992/density_He_over_Ne#

{
  "id": "density_He_over_Ne",
  "material": "He",
  "file": "He/shelton_1992__density_He_over_Ne.csv",
  "table": "tbl_9856decaf635",
  "quantity": "phase_match_density_ratio",
  "unit": "1",
  "abscissa_unit": "cm-1",
  "density": "real",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "reference_material": "Ne",
    "harmonic": 2,
    "process": "ESHG (electric-field-induced second-harmonic generation), periodic phase matching",
    "definition": "rho_gas / rho_reference_gas at equal wave-vector mismatch |Delta k| = (4 pi / lambda) |n(2w) - n(w)|; to first order in density = [alpha_ref(2w) - alpha_ref(w)] / [alpha_gas(2w) - alpha_gas(w)]; lambda = fundamental",
    "sample_gas": "Ne",
    "shelton_reference_gas": "He"
  }
}

Table 1 rows c): rho_He/rho_Ne at ESHG periodic phase match, as printed (gas He, reference Ne, as in shelton_1990). Pressures with a Paroscientific 1003K gauge (full scale 200 atm, +-0.02 atm), 26 C; density evaluation as in the earlier papers (virial equation of state, ref [1] = shelton_1990). ‘the phase match density ratios rho_He/rho_Ne are in excellent agreement with previous results’ (p. 2). The other rows’ ratios (d, e, f) are those of shelton_1989’s datasets (not repeated).