Linear Paul trap for strontium ions

We demonstrate a linear radio-frequency trap for confining strontium ions that is simply constructed nearly entirely with commercial off-the-shelf components. The electrodes of this trap are spaced to allow tight radial confinement, and segmented to give tight axial confinement with minimal distortion of the radio-frequency field. The resulting secular frequencies of the trap are 1 MHz in the radial direction and 100 kHz in the axial direction, the ions can be imaged with 2-3 mum resolution, and we detect over 20 000 photons per second per ion. This article describes the construction of the vital parts of the trap system, the laser system and optics used to Doppler cool the ions and to observe quantum jumps, and the operation and behavior of the complete system. (C) 2002 American Institute of Physics.