uiterwaal_1998#

C. J. G. J. Uiterwaal, D. Xenakis, D. Charalambidis, P. Maragakis, H. Schroder and P. Lambropoulos, “Generalized multiphoton-ionization cross sections of the rare gases for 500-fs, 248.6-nm pulses”, Phys. Rev. A 57, 392 (1998)

Source record · Catalogue · Review register

DOI: 10.1103/PhysRevA.57.392

Source kind: measurement

Recorded technique: Photoelectron (ATI) spectra of He, Ne, Ar and Kr in 500 fs, 248.6 nm pulses (a hybrid dye-excimer laser, 4.99 eV photons, 15 cm focusing lens, a 20 cm magnetically shielded electron time-of-flight spectrometer; ion yields with the same instrument or a confined-volume reflection time-of-flight spectrometer, p. 393). The maximum ponderomotive shift of the first ATI peak against the laser energy rises linearly and stops where the atom saturates; with a single-rate model, dP/dt = [1 - P] sigma_(N) Phi^N (Eqs. 1-3), and the shift U_p = 5.7e-15 I (eV, W/cm2; Eq. 7) the plateau gives the saturation intensity I_sat, defined by sigma_(N) (I_sat/hbar omega)^N t_eff = 1 (Eq. 9), and the generalized cross section (Eqs. 13-14), t_eff = int F^N dt the effective duration. ‘As our method relies on photoelectron kinetic energy measurements and not on laser intensity measurements’ (p. 393), neither needs the focal spot or an intensity calibration; the order N is the lowest-order perturbative one (He 5, Ar 4, Kr 3).

Materials in structured entries: Ar, He, Kr, Xe

Dataset quantities: multiphoton_ionization_cross_section, saturation_intensity

Contents: 7 datasets; 0 formulas.

Curation notes#

Journal pp. 392-400 = PDF pages 1-9. Identity checked against the first page.

WHAT IS TAKEN. The saturation intensities of He, Ar and Kr printed in the text (Sec. VI, p. 399: ‘I_sat,He = (6.9 +- 0.8) x 10^14 W cm^-2, I_sat,Ar = (1.0 +- 0.15) x 10^14 W cm^-2, and I_sat,Kr = (2.4 +- 0.6) x 10^13 W cm^-2’), and the experimental generalized cross sections of Table I (p. 399, tbl_02103ed7cb91; cells checked against the table image): He sigma_(5), Ar sigma_(4), Kr sigma_(3), and Xe sigma_(3), the last ‘calculated with Eq. (5) using the saturation intensity taken from the Xe-ion yield curve given in Ref. [6]’ (Charalambidis et al., Phys. Rev. A 50, R2822 (1994)), ‘with errors including uncertainties in the intensity calibration’: not from the ponderomotive shift. Not taken: Table I’s scaling-law, TDSE, TDHF and MQDT values (other papers’ theory), and neon, for which ‘a single-rate description is not valid’ (the ion yield’s slope reaches 6.4 +- 0.4 near saturation, against N = 5; four-photon resonances with the 3p, 3p’ manifold, p. 397), so the table prints ‘?’.

THE ERRORS OF TABLE I are printed as superscript and subscript, the superscript negative for He, Ar and Kr: ‘(0.9^-0.4_+9)’, ‘(1.3^-0.5_+1)’, ‘(1.2^-0.6_+1.7)’, and ‘(50^+350_-45)’ for Xe. Read as +9/-0.4, +1/-0.5, +1.7/-0.6 and +350/-45 (the larger error upwards, as sigma ~ I_sat^-N with N = 3 to 5 makes it); the schema holds no asymmetric uncertainty, so they are the parameters error_plus and error_minus, in the printed scale. The intensities’ errors are not defined (level not stated).

CONSISTENCY (tools/extract/uiterwaal_1998.py). Eq. (9) with a sech^2 pulse of 500 fs FWHM reproduces Table I from the saturation intensities: He 0.91e-152, Ar 1.57e-116 (printed 1.3e-116), Kr 1.22e-82.

WHAT THEY TEST. The rate’s multiphoton limit: the Keldysh parameter at I_sat is about 1.8 (He), 3.7 (Ar) and 7 (Kr); 248.6 nm is below the default’s range (350 nm) (TC-853).

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