Status of the Spin Splitter Experiment at IUCF

Abstract

During the last years a new polarization effect for protons or antiprotons was investigated theoretically^1,2. The idea is very simple: a storage ring consists of strong nonlinear fields, the quadrupoles. The nonlinear fields act on the spin of the particle by the Stern-Gerlach effect: the particles are kicked by a very small amount. This small kick produces betatron oscillations. During the next revolution the gradient of the quadrupole is (naturally) the same but the spin direction can be altered. As a result the strength and the direction of the kick can be different from revolution to revolution. When this time dependent kick follows a betatron oscillation the kicks can add up over many revolution and a macroscopic oscillation can be excited which can be detected by an outside detector. The principle is the same as in the one used for measuring the Q-value: small kicks add up over many revolutions and produce an oscillation with a significant amplitude.