A polarized atomic beam source was developed for the polarized internal storage-cell gas target at the magnet spectrometer ANKE of COSY-Julich. The intensities of the beams injected into the storage cell, measured with a compression tube, are $7.5cdo
t 10^{16}$ hydrogen atoms/s (two hyperfine states) and $3.9cdot 10^{16}$ deuterium atoms/s (three hyperfine states). For the hydrogen beam the achieved vector polarizations are $p_{rm z}approxpm0.92$. For the deuterium beam, the obtained combinations of vector and tensor ($p_{rm zz}$) polarizations are $p_{rm z}approxpm 0.90$ (with a constant $p_{rm zz}approx +0.86$), and $p_{rm zz}=+0.90$ or $p_{rm zz}=-1.71$ (both with vanishing $p_{rm z}$). The paper includes a detailed technical description of the apparatus and of the investigations performed during the development.
We present a measurement of the transverse intensity distributions of the COSY proton beam at the target interaction point at ANKE at the injection energy of 45 MeV, and after acceleration at 2.65 GeV. At 2.65 GeV, the machine acceptance was determin
ed as well. From the intensity distributions the beam size is determined, and together with the measured machine acceptance, the dimensions of a storage cell for the double-polarized experiments with the polarized internal gas target at the ANKE spectrometer are specified. An optimum storage cell for the ANKE experiments should have dimensions of 15mm x 20mm x 390mm (vertical x horizontal x longitudinal), whereby a luminosity of about 2.5*10^29 cm^-2*s^-1 with beams of 10^10 particles stored in COSY could be reached.
