Ionization of sodium and rubidiumnS,nP, andnDRydberg atoms by blackbody radiation

Abstract

Results of theoretical calculations of ionization rates of Rb and Na Rydberg atoms by blackbody radiation (BBR) are presented. Calculations have been performed for nS, nP and nD states of Na and Rb, which are commonly used in a variety of experiments, at principal quantum numbers n=8-65 and at three ambient temperatures of 77, 300 and 600 K. A peculiarity of our calculations is that we take into account the contributions of BBR-induced redistribution of population between Rydberg states prior to photoionization and field ionization by extraction electric field pulses. The obtained results show that these phenomena affect both the magnitude of measured ionization rates and shapes of their dependences on n. The calculated ionization rates are compared with the results of our earlier measurements of BBR-induced ionization rates of Na nS and nD Rydberg states with n=8-20 at 300 K. A good agreement for all states except nS with n > 15 is observed. We also present the useful analytical formulae for quick estimation of BBR ionization rates of Rydberg atoms.

Spontaneous Avalanche Ionization of a Strongly Blockaded Rydberg Gas

“…(II) Due to the Rydberg blockade, each Rydberg-excited atom blocks further excitations within a radius R c leading to density-density correlations which resemble those of a gas of hard-spheres. After a short time, the Rydberg density reaches steady state, however over time Rydberg atoms start to decay by a combination of blackbody photoionization [12] and ionizing collisions with atoms in the ground and intermediate states [23], which leads to a gradual increase in the number of charged particles in the system. (III) Once a critical number of ions N crit accumulates the resulting space charge can trap subsequently produced electrons.…”

Quasiclassical calculations of blackbody-radiation-induced depopulation rates and effective lifetimes of RydbergnS,nP, andnБетеров1, Ryabtsev2, Tretyakov3 et al. 2009Phys. Rev. ASelf Cite373122512View full textAdd to dashboardCite

“…Nevertheless, in order to improve the precision of the numerical calculations of BBR-induced depopulation rates we took into account transitions to all lower states and to the upper states with n ′ < n + 40. Omission of higher discrete states and continuum states reduces the accuracy by less than 0.5% [26,27]. The range of validity of the commonly used theoretical model of interaction of Rydberg atoms with blackbody radiation was discussed by Farley and Wing [4].…”

Imaging the evolution of an ultracold strontium Rydberg gas

“…However, because this growth is slow, other processes must be considered that might contribute to the growth in the number of visible ion cores after 1 D 2 excitations, such as population redistribution to states with attractive potentials by blackbody radiation (BBR) and BBR-induced photoionization. Calculations for hydrogen, helium, and the alkali metals [74][75][76] suggest that while the rates for excitation or deexcitation of Rydberg states by BBR depend on the particular atomic species, the rate for states with n ∼ 50 should be less than ∼1 × 10 4 /s. Whereas such rates might allow up to 10% of the parent 1 D 2 Rydberg states to undergo a transition to states of different on the time scale (∼10 μs) of the present measurements, this is insufficient to significantly increase the overall transition rate.…”