Ph. D. Thesis: Instrumentation development for physics with antiproton beams
by
Klas Marcks von Würtemberg(Stockholm University, Department of Physics)
→
Europe/Stockholm
FA32
FA32
Description
This thesis summarises work done in the preparation for the PANDA (antiproton ANnihilations at DArmstadt) experiment, that will be built at the HESR (High Energy Storage Ring) at FAIR (Facility for Antiproton and Ion Research) and for the PAX (Polarised Antiproton eXperiment) experiment proposed for the HESR.
For PANDA, characteristics of the electromagnetic calorimeter have been measured at the tagged photon beam facility at the MAX IV laboratory for 61 photon energies in the range 12-63 MeV. The tested detector array consisted of 5×5 PbWO4 (lead tungstate) crystals designed for the forward end-cap. The array was cooled to -25 °C and read out with either conventional photomultiplier tubes or vacuum phototriodes (VPTs), the photo-sensor proposed for the forward end-cap. The measured relative energy resolution with photomultiplier tubes, σ/E, (for example 6 % at 20 MeV) is well within the limits of the PANDA requirements. In tests with VPTs the lower signal-to-noise ratio deteriorates the resolution to a level suggesting that VPTs should not be used in PANDA.
For PAX, the analysing power with respect to the neutron in pd → ppn, with a transversely polarised proton beam with energy 49.3 MeV, has been measured. Data was taken at the COSY storage ring, Forschungszentrum Jülich, during an experiment in which the PAX collaboration successfully polarised a stored proton beam by spin filtering. In the measurement the beam was scattered of a deuterium cluster-jet target and the scattered protons were detected in the two silicon tracking telescopes of the ANKE detector system. The measured analysing power is compared to
the predictions by chiral effective field theory at next-to-next-to-leading order by interpolating on a precalculated grid and using the sampling method.
