Perpendicular laser cooling of a rotating ion plasma in a Penning trap

Itano, W., Brewer, L.R., Larson, D. and Wineland, D. (1988) Perpendicular laser cooling of a rotating ion plasma in a Penning trap. Physical Review A: General Physics, 38(11), pp. 5698-5706. (doi: 10.1103/PhysRevA.38.5698)

Abstract

The steady-state temperature of an ion plasma in a Penning trap, cooled by a laser beam perpendicular to the trap axis, has been calculated and measured. The rotation of the plasma, due to crossed E and B fields, strongly affects the minimum attainable temperature. This is because the velocity distribution of the ions, as seen by a laser beam intersecting the plasma at some distance from the axis of rotation, is skewed, and this leads to a change in the velocity distribution (and hence temperature) at which a steady state is attained. The calculated temperature is a function of the intensity, frequency, and position of the laser beam, and of the rotation frequency of the plasma. Temperatures of ⁹Be⁺ plasmas were measured for a wide range of experimental parameters. The lowest and highest temperatures were approximately 40 mK and 2 K. The measured and calculated temperatures are in agreement.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Brewer, Dr Laurence
• Authors: Itano, W., Brewer, L.R., Larson, D., and Wineland, D.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review A: General Physics
• ISSN: 0556-2791