Date of Award

Spring 2004

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physics

Committee Director

Charles I. Sukenik

Committee Member

Kenneth G. Brown

Committee Member

Mark Havey

Committee Member

Charles E. Hyde-Wright

Committee Member

Colm T. Whelan

Abstract

The first simultaneous cooling and confinement of two different atomic species from opposite sides of the periodic table in a dual magneto optical trap (DMOT) has been accomplished. The alkali-metal 85Rb and the noble gas 40Ar* have been simultaneously confined, characterized, and interspecies interaction parameters have been measured. The DMOT confined 1.2 × 106 85Rb atoms at a density of 1 × 1010/cm3 and 1.4 × 106 40Ar* atoms with a density of 1.2 × 1010/cm3. A collisional loss rate coefficient for Rb-Ar* has been determined to be γRb-Ar, = (4.8 ± 1.6) × 10−11cm3/s. A typical reduction of 3% of the florescence of the trapped 85Rb was observed when the 40Ar* trap was present. The loss of atoms from the dual trap is presumed to be caused by radiative escape and ionization losses, for an 40Ar* MOT it is due to Penning and associative ionization losses. An Ar* PI/AI ionization ratio of 6.7 ± 3.6 was determined, which makes the Penning ionization rate the dominant loss mechanism. The ionization rate was obtained with a SRS RGA200 mass spectrum analyzer specifically modified to work in conjunction with an ion optical field plate setup to collect the ions expelled from the MOT. The 85Rb was trapped with a 780 nm diode laser while the 40Ar* was slowed and trapped with a 811 nm Ti:sapphire laser, which was specifically modified to be locked to within 1 MHz of the atomic transition with a linewidth of ∼1 MHz. The metastable state 40Ar* was produced with a rf driven resonating cavity discharge which produced an atomic beam with an angular flux density of 4 × 1014 atoms s−1 sr−1.

DOI

10.25777/1v0d-fw62

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