Radio-frequency and laser spectroscopy studies of low-lying states in SrI

Abstract

Precision hyperfine structure (hfs) measurements in the 5s4d 1D 2 metastable state of STSr were performed using the laser radio-frequency double resonance method. The magnetic dipole and electric quadrupole interaction constants were found to be a= -5.5734(4) MHz and b = 55.421(6) MHz. In addition high-resolution laser spectroscopy experiments were performed in the 5s4d ~D2 ~--~ 5s6 p 1p~ and 5s4d IDz +-+ 5p4d aD z transitions in SrI. The isotope shifts in the transitions and the hfs in the upper states were determined. Comparison of the experimental results with corresponding relativistic selfconsistent-field (SCF) calculations shows that the states involved are very strongly perturbed. Therefore no reliable nuclear quadrupole moment for STSr can be deduced from the data presented here without more detailed calculations. A relativistic SCF calculation of the electron density at the nucleus was used in combination with muonic values of the nuclear mean square radii to evaluate the field shifts. From the experimental isotope shifts the specific mass shifts in the two transitions can then be deduced. This shift was found to be particularly large in the transition 5s4d aDz+-*5s6 p 1P 1 .

Isotope shifts and hyperfine structures investigation of doubly excited levels in SrI

“…For the 5p 4d 1D 2 level the small quadrupole contribution could not be estimated because of the larger error affecting the measured value of B. Values of A and B for the ~D2 level, were more accurately estimated by Grundevik et al [3] by means of radio-frequency double resonance method and for the constant A we observe a good agreement with our result.…”

“…In the last years many experimental and theoretical investigations on IS and hfs of this element were performed [, [1][2][3]. While much has been done for transitions involving single excited levels only few studies concern levels originated by doubly excited electrons.…”

High resolution laser spectroscopy of low-lyingp-states in Sr I and Ba I

“…Values of the hyperfine interaction constants A and B of the states 5s6p 1P1, 3P 1 in SrI and 6s7p 1p~ in BaI are presented in Table 1. The values for the 5s6p 1p~ state of SrI are in substantial agreement with the recent measurements of Grundevik et al [10]. Transition isotope shifts for the above transitions for the isotope pairs relative to 88Sr and 38Ba are given in Table 2.…”

“…In the present work, the hyperfine structure and isotope shifts associated with transitions to the second excited P states of SrI and BaI are measured with the use of a frequency-doubled ring dye laser recently developed by Eliel et al [8]. Our results on SrI complement those of earlier measurements on i) highly excited states [4,7,9], and 2) other lowlying states which are not connected by optical transitions with the atomic ground state [1][2][3][4][5][6][7][8][9][10]. We present below a parametric study of the level isotope shifts in SrI in which some of these results are connected.…”

Hyperfine structure in 5s 4d 3 D —5snf transitions of87Sr

“…Then, (4e) and the value for B (5s 4d ID2)= 55.421 MHz, which has been determined in optical-radio frequency double resonance experiments [20], can be used as a consistency check. The calculated value of B(3D2)+B(aD2) = 72(12) MHz, obtained from using the derived b4d3/2 and b4ds/2 values in the right side of (4e), compares well with the experimental sum of 73.4(10)MHz.…”