DEPENDENCE OF PROTON-BEAM POLARIZATION ON ION-SOURCE TRANSITION CONFIGURATIONS

The polarization of extracted SATURNE II proton beam as a function of different ion source configurations was studied. Two distinct experime nts were necessary for this purpose. In the first one, the LEFT-RIGHT instrumental asymmetry of the beam polarimeter was determined using an unpolarized beam. In the second one this correction factor was applie d to asymmetries measured with the beam from the polarized ion source in all polarization states. The measurements were carried out at the p roton beam kinetic energy 0.80 GeV, where the pp-elastic scattering an alysing power is near its maximum. The results confirmed that the two so-called ''unpolarized states'' of the source were polarized to sever al percent, whereas the absolute values of the beam polarizations in t he so-called ''polarized states'' were equal and opposite. It was obse rved that the hexapole lens of the ion source produced beam polarizati on in the absence of any transition. The beam polarization as a functi on of hexapole current, transition field attenuation, and spin rotatio n solenoid current was measured. It was also shown how to obtain a str ictly unpolarized beam using the polarized source only. The results ob tained with the SATURNE II ion source HYPERION may also be relevant to similar sources at other accelerators.