Non-neutral ion plasmas and crystals, laser cooling, and atomic clocks
- Time and Frequency Division, NIST, Boulder, Colorado 80303 (United States)
- Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)
Experimental work which uses Penning and Paul traps to confine non-neutral ion plasmas is discussed. Penning traps use a static uniform magnetic field and a static electric field to confine ions. The Paul trap uses the ponderomotive force from inhomogeneous radio-frequency fields to confine ions to a region of minimum field strength. In many atomic physics experiments, these traps are designed to produce a harmonic restoring force for small numbers of stored ions ([lt]10[sup 4]). Under these conditions and at low temperatures, both traps produce plasmas with simple shapes whose mode properties can be calculated exactly. Laser cooling has been used to reduce the temperature of trapped ions to less than 10 mK with ion spacings less than 20 [mu]m. At such temperatures and interion spacings, the Coulomb potential energy between nearest neighbor ions is greater than the ion thermal energy and the ions exhibit spatial correlations characteristic of a liquid or crystal. Laser beams also apply a torque which, by changing the plasma angular momentum, changes the plasma density. Atomic clocks are an important application of ion trap plasmas. Better control of the plasma dynamics will reduce fluctuations in the relativistic time dilation, yielding better clocks.
- OSTI ID:
- 6922569
- Journal Information:
- Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:5; ISSN PHPAEN; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
700350* -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
ATOMIC CLOCKS
CHARGED PARTICLES
COLLISIONS
CONFINEMENT
COOLING
CRYSTALS
ELECTROMAGNETIC RADIATION
ION COLLISIONS
IONS
LASER RADIATION
PHOTON COLLISIONS
PHOTON-ION COLLISIONS
PLASMA CONFINEMENT
PLASMA PRODUCTION
PONDEROMOTIVE FORCE
RADIATIONS
RADIOWAVE RADIATION
TRAPS