We present calculations of high Rydberg states for the lithium atom by two different theoretical methods. The first method is based on the $R$ -matrix theory to obtain the energy levels and the quantum defects for the $1{s}^{2}nd\phantom{\rule{0.2em}{0ex}}^{2}D$ and $1{s}^{2}nf\phantom{\rule{0.2em}{0ex}}^{2}F$ states and their adjacent continuum states. Then the quantum defect functions of the two channels are obtained which vary smoothly with energy based on quantum defect theory. The second method is based on the full core plus correlation method. Our results are compared with data in the literatures; especially the results of the $R$ -matrix method are in excellent agreement with microwave measurements for the lithium atom.We present calculations of high Rydberg states for the lithium atom by two different theoretical methods. The first method is based on the $R$-matrix theory to obtain the energy levels and the quantum defects for the $1{s}^{2}nd\phantom{\rule{0.2em}{0ex}}^{2}D$ and $1{s}^{2}nf\phantom{\rule{0.2em}{0ex}}^{2}F$ states and their adjacent continuum states. Then the quantum defect functions of the two channels are obtained which vary smoothly with energy based on quantum defect theory. The second method is based on the full core plus correlation method. Our results are compared with data in the literatures; especially the results of the $R$-matrix method are in excellent agreement with microwave measurements for the lithium atom.

Physical Review AApr 14, 20058 citations

Ionization of nS, nP, and nD lithium, potassium, and cesium Rydberg atoms by blackbody radiation

Ilya I. Beterov, I. I. Ryabtsev, Denis B. Tretyakov +2 more

The results of theoretical calculations of the blackbody ionization rates of lithium, potassium, and cesium atoms residing in Rydberg states are presented. The calculations are performed for nS , nP , and nD states in a wide range of principal quantum numbers, n = 8−65, for blackbody radiation temperatures T = 77, 300, and 600 K. The calculations are performed using the known quasi-classical formulas for the photoionization cross sections and for the radial matrix elements of transitions in the discrete spectrum. The effect of the blackbody-radiation-induced population redistribution between Rydberg states on the blackbody ionization rates measured under laboratory conditions is quantitatively analyzed. Simple analytical formulas that approximate the numerical results and that can be used to estimate the blackbody ionization rates of Rydberg atoms are presented. For the S series of lithium, the rate of population of high-lying Rydberg levels by blackbody radiation is found to anomalously behave as a function of n . This anomaly is similar to the occurrence of the Cooper minimum in the discrete spectrum.The results of theoretical calculations of the blackbody ionization rates of lithium, potassium, and cesium atoms residing in Rydberg states are presented. The calculations are performed for nS , nP , and nD states in a wide range of principal quantum numbers, n = 8−65, for blackbody radiation temperatures T = 77, 300, and 600 K. The calculations are performed using the known quasi-classical formulas for the photoionization cross sections and for the radial matrix elements of transitions in the discrete spectrum. The effect of the blackbody-radiation-induced population redistribution between Rydberg states on the blackbody ionization rates measured under laboratory conditions is quantitatively analyzed. Simple analytical formulas that approximate the numerical results and that can be used to estimate the blackbody ionization rates of Rydberg atoms are presented. For the S series of lithium, the rate of population of high-lying Rydberg levels by blackbody radiation is found to anomalously behave as a function of n . This anomaly is similar to the occurrence of the Cooper minimum in the discrete spectrum.

Journal of Experimental and Theoretical PhysicsJul 1, 200810 citations

We present calculations of high Rydberg states for the lithium atom by two different theoretical methods. The first method is based on the

R

-matrix theory to obtain the energy levels and the quantum defects for the

1{s}^{2}nd\phantom{\rule{0.2em}{0ex}}^{2}D

and

1{s}^{2}nf\phantom{\rule{0.2em}{0ex}}^{2}F

states and their adjacent continuum states. Then the quantum defect functions of the two channels are obtained which vary smoothly with energy based on quantum defect theory. The second method is based on the full core plus correlation method. Our results are compared with data in the literatures; especially the results of the

R

-matrix method are in excellent agreement with microwave measurements for the lithium atom.