R Bieber

Performance of the KVI in-beam polarimeter

A beam polarimeter for medium-energy protons and deuterons has been constructed. Its operation is based on the elastic-scattering reactions (p) over right arrow + p or (d) over right arrow + p. The outgoing particles are detected in kinematical coincidence in four independent reaction planes, each equipped with two pairs of phoswich detectors

Three-nucleon force effects in the dp-breakup at 130 MeV

Indications for three nucleon force (3NF) effects in PJd elastic scattering and in specific kinematical configurations of the deuteron breakup reaction became motivation for complex studies of the three nucleon system dynamics in the dp breakup process over a broad region of phase-space. A dedicated experiment is aimed at precise determination of cross sections and both vector and tenser analyzing powers for the H-1((p) over right arrow pp)n breakup reaction at 130 MeV deuteron beam energy. The experiment, employs a position-sensitive detection system covering a large solid angle and allowing for excellent particle identification. The first data taking run has been completed and the accumulated data are being analyzed. The results will be compared with the rigorous calculations within the Faddeev formalism, including various nucleon-nucleon potentials and 3NF models.

Investigation of effects beyond two-body forces in three-nucleon systems

An experiment has been performed at KVI to measure vector analyzing powers and differential cross sections of the D((p) over right arrow pd) reaction as a function of incident beam energy. The measurements have been performed so far at several kinetic energies of the incoming particle between 108 MeV and 170 MeV. In this contribution, the preliminary results for the vector analyzing power A(y) will be presented.

Measurements of the Analyzing Power of Elastic pd-Scattering at 190 MeV

A beam-polarimeter for medium energy protons and deuterons (E=100-200 MeV) has been constructed. Its operation is based on the p + d, p + p and d + p elastic scattering with coincident detection of both particles in 4 independent planes. The 16 detectors of the polarimeter have a phoswich construction to ensure particle identification. With this device the analyzing power, A(y), of p + p elastic scattering has been measured at 190 MeV for CM-angles of 25 degrees to 115 degrees in two planes, monitored by p Sp elastic scattering in the two other planes. The target was mixed CH2/CD2. This allowed for simultaneous extraction of A(y)(p, d) and the beam polarizations. The analyzing power is compared with calculations based on the Bonn-potential including partial waves up to J = 5.