Click here to download thesis: Laser cooling and trapping of Ca+ions in a Penning trap

Title: Laser cooling and trapping of Ca+ ions in a Penning trap


This thesis describes the efforts undertaken to achieve the goal of trapping and Doppler cooling single Ca+ ions in the Penning trap. This will be used particularly for studying decoherence effects in the Penning trap which represents the long term goal of the Ion Trapping group at Imperial College London.

Trapping and Doppler cooling of Ca+ ions in the Paul, combined and Penning traps are demonstrated. The operation in the Paul trap was signi cant as it allowed the laser wavelengths and detection system to be calibrated and the trap to be characterised before operation in the Penning trap was attempted. The operation in the combined trap was used to set the laser wavelengths to their correct values for use in the Penning trap. Doppler cooling of Ca+ ions in the Penning trap required the use of 2 × 397nm lasers, 2 × 866nm lasers with their input currents frequency modulated to produce sidebands and 1 × 854nm laser.

The trapping of small numbers of Ca+ ions in the Penning trap is demonstrated. Analysis of the uorescence trace of ions undergoing quantum jumps allows us to infer that the number of ions present is probably two. Although single Ca+ ions were not successfully trapped in the Penning trap, the results show that there is no fundamental problem with the laser cooling scheme used.

Improvements to the current setup are suggested with the aim of trapping single Ca+ ions in the Penning trap.


Issue Date: 8 September 2003

Supervisor: Thompson, Richard

                    Segal, Danny

Item Type:  Physics PhD Thesis