The new high intensity polarized proton and deuteron source for the Bonn isochronous cyclotron

Abstract An atomic-beam polarized ion source for the production of polarized protons and deuterons is described. Beam intensities of 160 μA for polarized protons and deuterons are obtained at an emittance of 9π cm · rad · eV . Within the phase space accepted by the Bonn isochronous cyclotron 50 μA of deuterons and 35 μA of protons were measured. The atomic beam emerging from a liquid nitrogen cooled dissociator nozzle is polarized and focussed by two tapered sextupole magnets. Two radiofrequency transitions can be mounted either before or behind the second sextupole, leading to theoretical values for deuterium vector and tensor polarizations of P z =±1 and P zz =−2, respectively. The polarized atoms are ionized by electron impact inside a cold-cathode Penning ionizer working at a magnetic field of 4 T produced by a superconducting solenoid. The efficiency for this ionizer is estimated to be η =6.2×10 −2 .