Systematic measurements for low electron-ion relative velocity
The influence of the longitudinal magnetic field
This figure shows the longitudinal (from the IndAcc measurement ) friction coefficient and the cooling rate as function of the longitudinal magnetic field for 12C6+ ions (ne = 8 · 106 cm-3, Iion = 20 µA, expansion factor 9.6). Below 300 Gauss there is a dramatic drop in the friction coefficient with decreasing magnetic field whereas above about 300 Gauss the longitudinal friction coefficient remains constant. Different plotting symbols result from different beam times.
This figure shows the transverse cooling rates as function of the longitudinal magnetic field for 12C6+ ions (ne = 8 · 106 cm-3, Iion = 20 µA, expansion factor 9.6). Below about 400 Gauss there is also a dramatic drop in the cooling rate with decreasing magnetic field whereas above 400 Gauss the transverse cooling rate seems to be increasing with increasing magnetic field. The colours red and black denote data taken within one beam time.