First Results from the K-State MOTRIMS Experiment For the first round of experiments, we chose to study 6 keV Cs+ + Rb(5s), Rb(5p). [Note we get both states of Rb as a consequence of the cooling and trapping lasers.] What follows are a few key slides, briefly showing the setup, and some results.

EXPERIMENTAL SETUP Re-Pump LASER Trapping LASER Anti-Helmholtz Coil Ion Beam Spectrometer Recoil Ion 2D-PSD Projectile 2D-PSD Anti-Helmholtz Coil Electrostatic deflector Faraday cup

BEAM LINE Projectile PSD and F.cup Recoil ion Spectrometer Einzel lens Ion gun Electrostatic deflector Recoil ion PSD MOT viewer

COLD RUBIDIUM ATOM CLOUD Our first ever MOT April 6th ,2000 Beam aperture Trapped atoms The rubidium cloud is a 0.6 mm diameter sphere with a few 1010 atoms/cm3 density 2 cm

Determination of MOT Temperature The “drop & recapture” technique was used to roughly determine the temperature of the Rb MOT. Result: 129K  50K.

Relevant Energy Level Diagram for Rb-Cs Collisions

2-D plot showing scattering angle vs. Q-value Note the structure in the scattering angle for the 5s-6s line.

Counts vs Q-value The Q-value is used to identify the initial and final states in the collisions. The red labels are used to identify capture from excited Rb atoms, while blue labels are used to identify capture from ground state Rb atoms

Uncorrected x-y data for Rb(5s)-Cs(6s) transition Same as at left, but corrected for B-field distortion