The HERMES recoil photon detector and nuclear pt-broadening at HERMES.

Deze thesis gaat over de bouw en de test van de hermes recoil foton detector. Het tweede deel handelt aangaande verbreding van de transversale impuls van hadronen gevormd in een nucleaire omgeving ter vergelijking met diegene die gevormd worden aan een nuceon (proton of neutron). Dit verschaft informatie over hoe een hadron gevormd wordt uit quarks in functie van ruimte en tijd

Nuclear p_t broadening at HERMES

The first direct measurement of p_t-broadening effects in cold nuclear matter has been studied as a function of several kinematic variables for different hadron types. The data have been accumulated by the HERMES experiment at DESY, in which the HERA 27.6 GeV lepton beam scattered off several nuclear gas targets.Comment: 4 pages, 5 figures, submitted to DIS 2007 proceeding

The HERMES recoil photon-detector and nuclear p(t)-broadening at HERMES

Deze thesis gaat over de bouw en de test van de hermes recoil foton detector. Het tweede deel handelt aangaande verbreding van de transversale impuls van hadronen gevormd in een nucleaire omgeving ter vergelijking met diegene die gevormd worden aan een nuceon (proton of neutron). Dit verschaft informatie over hoe een hadron gevormd wordt uit quarks in functie van ruimte en tijd

Comparing the output of measured and GEANT4 simulated X-ray tubes

Monte Carlo simulation codes that model particle interactions with matter, including GEANT4, can be used to support the development of novel X-ray tubes and instruments for applications in industry and research. Based on our knowledge, simulations of the output of transmission-geometry X-ray tubes have not yet been conducted in GEANT4. Simulations of reflection-geometry tubes are scarce, with a limited number of studies investigating the capability and accuracy of GEANT4 in this domain. Therefore, the aim of this work is to benchmark GEANT4 for the characterisation of X-ray tubes with industry applications, using for the first time a range of X-ray tubes geometries and high voltages. In this work, GEANT4 is benchmarked against experimental measurements performed at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia, with both transmission and reflection X-ray tubes. High voltages between 17 kV and 42.5 kV for tungsten, molybdenum, gold, and silver targets are investigated. The measurements have been performed with a MXR packaged X-ray tube (reflection) and Magnum X-ray tubes (transmission) and a fast silicon drift detector (SDD). Our study shows that GEANT4 predicts the bremsstrahlung continuum output of transmission and reflection X-ray tubes, in agreement with the experimental measurements. The Penelope physics models, distributed with GEANT4, and the GEANT4 X-ray fluorescence data libraries ANSTO HF, based on the Hartree-Fock approach, exhibit the best agreement against experimental measurements. Depending on the high voltage, target and X-ray line agreement was found to vary between 10% and 300%. Differences between GEANT4 and experimental data are more significant for lower voltage X-ray tube measurements and are most likely due to limitations in the ionisation electron cross-section and/or atomic relaxation data libraries used. As next steps, it is recommended to validate GEANT4 against other, independent experimental measurements to corroborate the results of this work. In addition, it would be useful to repeat the same study with other general purpose Monte Carlo codes for radiation physics to compare their capability against GEANT4 in this application domain

Beam-helicity asymmetries for single-hadron production in semi-inclusive deep-inelastic scattering from unpolarized hydrogen and deuterium targets

A measurement of beam-helicity asymmetries for single-hadron production in deep-inelastic scattering is presented. Data from the scattering of 27.6 GeV electrons and positrons off gaseous hydrogen and deuterium targets were collected by the HERMES experiment. The asymmetries are presented separately as a function of the Bjorken scaling variable, the hadron transverse momentum and the fractional energy for charged pions and kaons as well as for protons and anti-protons. These asymmetries are also presented as a function of the three aforementioned kinematic variables simultaneously