Measurement of collisional relaxation of rydberg 3S-nS(nD) and 3P1/2-3P3/2 transitions of Na by trilevel echoes and collisional velocity changes of Na (3S and 3P/sub 1/2/ states) by stimulated echo

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1981

OSTI ID:6427608

Kachru, R

Comprehensive measurements of the noble (and molecular) gas-induced-broadening cross sections of the Na 3S-nS (3S-nD) transitions, from n = 5 to 40 (n = 4 to 40) have been made. These measurements were made using trilevel echo technique. It was found that for noble gas perturbers the cross section increases as the geometric cross section at low values of n, and then, at a value of n which depends on the particular noble gas, begins to decrease and eventually reach an asymptotic value at high n. The broadening cross section for the nearly degenerate D states is significantly larger than those for the S- states and clearly shows the effects of the I-changing collisions. It was found that the noble gas data for S states is in good qualitative agreement with Omont's theory. The broadening rates measured with molecular perturbers (N/sub 2/ and CO) differ in some respects with those observed with nobles gas perturbers. Using the stimulated photon echo technique, the collisional relaxation of the Na atom in a single state (3S or 3P/sub 1/2/) (i.e. velocity changes experienced by the ground state or excited state Na atoms) in collisions with He and CO has been studied. It was found that the ground-state (3S) Na atoms ave a total cross sections of approx. = 176 = A/sup 2/ (420 A/sup 2/) for velocity changing collisions with He(CO) and that they experience an average velocity change of approx. = 460 cm/s (600 cm/s). A scattring kernel of Lorentzian form is shown to be consistent for the data for He, whereas an exponential kernel best describes the data for CO. A lower bound was found on the cross section for the Na(3P/sub 1/2/)-He collisions.

• Research Organization: Columbia Univ., New York (USA)
• OSTI ID: 6427608
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COLLISIONS
CORRECTIONS
CROSS SECTIONS
D STATES
DATA
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXPERIMENTAL DATA
FINE STRUCTURE
FLUIDS
GASES
GROUND STATES
HELIUM
INFORMATION
KERNELS
METALS
NONMETALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
RARE GASES
RELAXATION
RYDBERG CORRECTION
S STATES
SODIUM
VELOCITY