NSCL, East Lansing, Michigan
Heavy-ion beams from an ECR type ion source have been shown to be structurally complex and to have a strong cross-correlation associated with their formation in and extraction from a high magnetic field with a strong sextupole content [1]. The emittances of such beams tend to be unavoidably large (compared to low magnetic field source types) yet because of cross-correlations, resistant to improvement by normal collimation methods. Recent developments with beam from the 14 GHz room temperature ECRIS at the NSCL indicate that careful beam line tuning to pass specific parts of the beam structure can allow greatly reduced 4-dimensional emittances without losing a disproportionate amount of the total intensity.
[1] "Ion beam extracted from a 14 GHz ECRIS of CAPRICE Type", P. Spaedtke, et al., 17th Int. Work. On ECR Ion Sources, 17th-21st Sep., 2006, Lanzhou, China
