larochelle_1998

S. F. J. Larochelle, A. Talebpour and S. L. Chin, “Coulomb effect in multiphoton ionization of rare-gas atoms”, J. Phys. B: At. Mol. Opt. Phys. 31, 1215 (1998)

Source record · Catalogue · Review register

DOI: 10.1088/0953-4075/31/6/009

Source kind: measurement

Recorded technique: Ion yields (singly charged) of Xe, Kr, Ar, Ne and He against peak intensity over seven to eight orders of magnitude of yield: Ti:sapphire laser, 800 nm, 200 fs, linearly polarised, f/100 focusing into a UHV chamber (background 2 x 10^-9 Torr); time-of-flight mass spectrometer, electron multiplier tube; each ion curve combined from intensity scans at fill pressures 10^-8 to 10^-4 Torr (technique of Talebpour, Chien and Chin, J. Phys. B 29, 5725 (1996)). The yields are compared with ADK, SFA, Szoke’s, Krainov’s and the PPT rates integrated over the pulse and the focal volume (Chang et al. 1992) (pp. 2-5).

Materials in structured entries: None recorded.

Dataset quantities: None recorded.

Contents: 0 datasets; 0 formulas.

Curation notes

Journal pp. 1215-1224 = pdf pages 1-10. Identity checked against pdf p. 1 (S F J Larochelle, A Talebpour and S L Chin; received 21 July 1997). The companion of talebpour_1999 (the same apparatus), which cites it as their ref. 11 with the wrong volume (‘32 1998 1215’).

WHY NO YIELDS ARE TAKEN. The ion yields are in Figs. 1-5 only (Xe, Kr, Ar, Ne, He: ion signal against peak intensity, lower scale, and the Keldysh gamma, upper scale, with the Szoke, PPT, ADK and SFA curves; Krainov’s ‘grossly overlaps with the PPT curve and is thus not shown’); nothing is printed as a number and nothing is digitised.

CALIBRATION (p. 2). ‘The absolute intensity calibration is based on a comparison with the saturation intensity predicted by the ADK formula in the case of helium’ (after Walker et al. 1994, walker_1994, whose He+ yield agrees with ADK near saturation). The other gases are calibrated against He by scanning the saturated parts of all the curves without changing the conditions: ‘The accuracy in the relative intensity calibration between one given ion curve and the reference He curve is estimated to +-5%’ (the error bar in each figure). The absolute ion signal is not used: theory and experiment are matched at saturation (‘due to the kind of detector used (electron multiplier tube), it is very difficult to know the precise number of ions detected in each shot’). Multiply charged ions contribute ‘not more than 2% or 3%’ before saturation of the first charge (p. 3).

FINDINGS STATED. ADK overestimates the slopes, ‘especially for the low ionization potential gases (Xe and Kr)’, and agrees only in the upper part of the He and Ne yields, where gamma < 0.5 (pp. 5-6); SFA ‘underestimates strongly (between two and three orders of magnitude) the ionization rate for all gases’ (p. 6); Szoke’s model agrees poorly for Xe and overestimates the others (p. 6). ‘The PPT model predicts accurately the ionizing rates of He and Ne, while for Ar it is slightly overestimated. For Xe and Kr, the deviation is larger. Still, the theoretically predicted and the experimentally observed rates agree to within a factor 2’ (p. 7). The structures in the Xe and Kr yields (dynamic trapping) are not reproduced by PPT (p. 7).

THE RATES (pp. 3-5). Eq. (1), ADK: W_mADK = |C_n*l*|^2 f_lm E_i sqrt(6/pi) (2(2E_i)^(3/2)/F)^(2n* - |m| - 3/2) exp(-2(2E_i)^(3/2)/(3F)); Eq. (2) f_lm = (2l + 1)(l + |m|)!/(2^|m| |m|! (l - |m|)!); Eq. (3) |C_n*l*|^2 = 2^(2n*)/(n* Gamma(n* + l* + 1) Gamma(n* - l*)); l* = n* - 1 and ‘the ground state values for n* and l’, averaged over m, Eq. (4): W = (1/(2l + 1)) sum_m W_m. Eq. (10), PPT: W_nPPT = |C_n*l*|^2 f_lm E_i sqrt(6/pi) (2(2E_i)^(3/2)/F)^(2n* - |m| - 3/2) (1 + gamma^2)^(|m|/2 + 3/4) A_m(omega, gamma) exp(-(2(2E_i)^(3/2)/(3F)) g(gamma)), Eq. (11) g(gamma) as in talebpour_1999; A_m from Perelomov et al. (1966) and Ilkov et al. (1992; ilkov_1992 Eq. (8)), with the more precise alpha, beta, rho of Perelomov et al. (1968); also averaged over m. The Coulomb correction factors: Eq. (8) I_KRA = (2Z^2/(n*^2 F r))^n* (Krainov), Eq. (9) I_PPT = (2(2E_i)^(3/2)/F)^n*. ‘for unpolarized atoms, the PPT model is independent of l because, in the sum over m, only the term with m = 0 contributes’ (p. 5): the reason talebpour_1999 can use l = m = 0 for molecules. These are the correct forms of talebpour_1999’s misprinted Appendix A (its Eqs. (1), (2), (7)). Keldysh gamma = sqrt(E_i/(2 U_p)) (p. 2).

TABLE 1 (tbl_266767756ee8, p. 8, image checked; notes only), ‘Critical gamma for different gases at which the Coulomb correction should break down’: gamma_cr and gamma_k = 2E_i/(lambda omega), Eq. (14), lambda = n*: Xe 5.8, 14.8; Kr 8.3, 18.3; Ar 9.4, 21.9; Ne 9.8, 35.1; He 10.0, 42.6. gamma_cr = sigma_cr gamma_k, sigma_cr the limit of real solutions of Eq. (15) (Perelomov et al. 1968); the PPT Coulomb correction holds for gamma << gamma_cr. Not a dataset: a validity limit derived from the model, not a constant fitted within it, and not a property of the atom. gamma_k checked: 2E_i/(n* omega) with E_i = 0.4458 and 0.9036 hartree and omega = 0.05695 au (800 nm) gives 14.78 (Xe) and 42.66 (He), as printed (2026-09-27).

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.