The ASTRID electron cooler was built and used on the tandem accelerator before ASTRID became operational. After careful characterisation of the beam properties (energy spread, profile etc.) it was used to measure cross-sections for radiative recombination and dielectric recombination with multiply charged ions. In 1992, it was equipped with a stronger gun magnet to provide adiabatic expansion of the electron beam and moved to its present location. It has successfully been used to cool stored ions and to study electron-ion interactions including molecular ions and negative ions.

Cooler Characteristics

Parameter	Value
Beam energy	10-2000 eV
Interaction length	95 cm
Beam diameter	1-5 cm
B-field in gun region	<2 kG
B-field in interaction region	100-300 G
Temperature in perpendicular axis	0.02-0.15 eV
Temperature in parallel axis	0.0005-0.001 eV

For more information, please look at the electron-ion interactions home page or contact .

Last Modified 13 June 2009