Initial Investigations Of(np)-Scattering With A Polarized Deuterium Target At ANKE-COSY

The understanding of the forces among nucleons is fundamental to the whole of nuclear and hadronic physics. The nucleon-nucleon(NN) scattering is the ideal probe to study the nuclear forces. The scattering amplitudes for the complete description of the NN interactions can be reconstructed from phase-shift analyses(PSA), which requires measurements with polarized experiments. The existing data allow to extract unambiguous proton-proton(pp) amplitudes below 2 GeV.However, there is very little known about the neutron-proton(np) system above800 MeV nucleon energy. ANKE-COSY collaboration has embarked on a systematic program which aims to extract the np scattering amplitudes through the deuteron-proton charge-exchange process dp → {pp}sn. First part of the program via polarized deuteron beam and hydrogen target allowed successful measurement of np amplitudes up to 1.135 GeV nucleon energy, which is the maximum nucleon energy that can be accessed with deuteron beam at COSY. Via inverse kinematics,i.e. using polarized deuterium target incident by proton beam, the np study can be extended up to 2.8 GeV, the highest energy available at COSY. The method of inverse kinematics has to be validated prior to the production experiment. As the proof-of-principle(POP) experiment, the initial research has been conducted at proton energy Tp= 600 MeV using a polarized deuterium target. The projectiles were measured by two silicon tracking telescopes(STT) placed closed to the target and by the ANKE sub-detection systems. Four polarization modes of the deuterium target were employed. In order to increase the effective target thickness, polarized deuterium atoms produced by the atomic beam source(ABS)was ?lled into a storage cell, where the circulating COSY beam collides with the target. The target polarizations were measured using the proton-deuteron elastic reaction. The vector and tensor analyzing powers Ayand Ayyof p?d → n{pp}swere measured for momentum transfers q 160 MeV/c. These data connect smoothly with the previous measurements at q 140 MeV/c performed using a polarized deuteron beam. The data presented in present thesis are well reproduced by the impulse approximation using the SAID np amplitudes. The results therefore proves that it is possible to continue the np programme at higher energies at ANKE.