Publications
Chosen filters:
Chosen filters:
Simulation of Ultrasonic Beam Propagation From Phased Arrays in Anisotropic Media Using Linearly Phased Multi-Gaussian Beams KU Leuven
Phased array ultrasonic testing is widely used to test structures for flaws due to its ability to produce steered and focused beams. The inherent anisotropic nature of some materials, however, leads to skewing and distortion of the phased array beam and consequently measurement errors. To overcome this, a quantitative model of phased array beam propagation in such materials is required, so as to accurately model the skew and the distortion. The ...
Monte Carlo calculation of beam quality correction factors in proton beams using PENH KU Leuven
This work calculates beam quality correction factors ([Formula: see text]) in both modulated and unmodulated proton beams using the Monte Carlo (MC) code [Formula: see text]. The latest ICRU 90 recommendations on key data for ionizing-radiation dosimetry were adopted to calculate the electronic stopping powers and to select the mean energy to create an ion pair in dry air ([Formula: see text]). For modulated proton beams, [Formula: see text] ...
Multi-transmit beam forming for fast cardiac imaging: quantitative analysis of the cross-talk between MLT beams KU Leuven
As an alternative to parallel receive beam forming, transmitting multiple beams simultaneously (i.e. multi-line transmit (MLT)) has been proposed to obtain high frame rates when imaging the heart. However, this approach has received less attention likely due to potential artifacts as a result of cross-talk between MLT beams. In this study, the cross-talk level of two MLT beams with different opening angles was quantitatively evaluated by ...
Performance of CMS hadron calorimeter timing and synchronization using test beam, cosmic ray, and LHC beam data Ghent University University of Antwerp
Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator KU Leuven
The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently post-accelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance ...
Biological impact of beam trawling revisited: A comparison of direct mortality of benthic fauna between tickler chain and pulse beam Research Institute for Agriculture, Fisheries and Food
Beam trawling uses heavy gear combined with tickler chains that are dragged across the seabed disturbing the upper layers of sediment and causing damage or mortality to benthic organisms. Recently, Dutch fishermen have replaced the tickler chains of the beam trawls by electrodes as alternative stimulation for catching flatfish. The pulse is claimed to have less of an in impact on benthic organisms than the traditional beam. In June 2013, sea ...
Physical impact of beam trawling revisited: sediment resuspension and disturbance of tickler chain and pulse beam trawling Research Institute for Agriculture, Fisheries and Food
Beam trawling causes physical disruption to the seafloor through physical contact of the gear components on the sediment and the resuspension of sediment into the water column in the turbulent wake of the gear. Recently Dutch beam trawlers have replaced tickler chains by electrodes as alternative stimulation for catching flatfish. It is claimed that benthic impacts are reduced. Here we report on trials in a medium sand fishing ground to compare ...
Beam hardening and partial beam hardening of the bowtie filter: effects on dosimetric applications in CT KU Leuven
Purpose: To estimate the consequences on dosimetric applications when a CT bowtie filter is modeled by means of full beam hardening versus partial beam hardening. Method: A model of source and filtration for a CT scanner as developed by Turner et. al. [1] was implemented. Specific exposures were measured with the stationary CT X-ray tube in order to assess the equivalent thickness of Al of the bowtie filter as a function of the fan angle. Using ...
Implementing the complete beam hardening effect of the bowtie filter versus scaling beam intensities: effects on dosimetric applications in computed tomography KU Leuven
The bowtie filter is an essential element of computed tomography scanners. Implementation of this filter in a Monte Carlo dosimetry platform can be based on Turner's method, which describes how to measure the filter thickness and relate the x-ray beam as a function of bowtie angle to the central beam. In that application, the beam hardening is accounted for by means of weighting factors that are associated to the photons according to their ...