Angular momentum conservation follows from cylindrical symmetry. By scanning the beam transversely across the plasma, we were able to show that the observed torque was only weakly sensitive to displacement. However exploration of the greater sensitivity to beam angle was hampered by the limited strength of Cooler steering magnets in the S region. It is hoped to extend the angle scans by installing a mini-chicane, and to settle the issue of whether a plasma target might serve as a coasting beam angle diagnostic. In addition, development of a higher B field trap continued through the past year.
Higher fields permit more effective plasma compression by the rotating field technique.
Smaller denser plasmas will extend the range of accessible beam-plasma interaction effects. For more information see Nonneutral Plasma Research at IUCF Experiments in the IUCF Cooler have been very important for understanding the accelerator physics of spin in a storage ring. Developing the spin-flipping technique is important for high energy spin experiments since frequent reversals of the beam polarization direction can significantly reduce the systematic errors in an experiment's spin asymmetry measurements. An rf solenoid was used earlier to spin-flip polarized proton beam stored in the Cooler with and without a Siberian snake. Since a solenoid's spin rotation decreases linearly with momentum, a solenoid is impractical for spin-flipping in high energy rings.