G.H. Jansen - Academia.edu (original) (raw)
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National College of Business Administration and Economics
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Papers by G.H. Jansen
Optik, 1983
On discute sur l'influence des interactions entre des electrons individuels sur la qualite du... more On discute sur l'influence des interactions entre des electrons individuels sur la qualite du faisceau. Les aspects statistiques et dynamiques du grand nombre de particules sont reduits a un probleme a deux particules. L'effet de Boersch et le deplacement trajectoire sont calcules pour une geometrie simple
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1987
A fast algorithm for the ray tracing of an ensemble of interacting charged particles in drift spa... more A fast algorithm for the ray tracing of an ensemble of interacting charged particles in drift space has been developed for a fast Monte Carlo simulation program. It is based on a decomposition of the full interaction into a sum of two particle effects, which are estimated by means of analytical results. It is demonstrated that the reduction to two particle dynamics is allowed for practical beams used in lithography and microscopy, without decreasing the accuracy of the simulation. The new algorithm is up to two orders of magnitude faster (depending on the specific beam considered) than the algorithm using third order numerical integration with a variable time step. The program can be used on a fast microcomputer keeping the run time within practical limits.
International Journal of Multiphase Flow, 2000
A physical model for the dynamics of a dispersion of solid spherical particles in an incompressib... more A physical model for the dynamics of a dispersion of solid spherical particles in an incompressible viscous¯uid is outlined and used to calculate the turbulence modulation in a stationary, homogeneous and isotropic turbulent¯ow with particles. Starting from a postulated¯uid turbulence spectrum in the absence of particles, the physical model predicts the corresponding¯uid turbulence spectrum in the presence of particles and the particles turbulence spectrum as function of frequency and wavenumber. There are two versions of the model. The ®rst one uses a point-force approximation for the particles and takes into account the hydrodynamic interaction between the particles. The second version accounts for the detailed¯ow around the (®nite-diameter) particles, but does not consider their hydrodynamic interaction. The spectra, calculated with the two versions, are used to determine the turbulence intensity of the¯uid and particles as function of three relevant dimensionless groups. It is found that in general the dierences between the results of the point-particle model and the ®nite-diameter-particle model are signi®cant. So one has to be careful with point-particle models. The eect of the hydrodynamic interaction between the particles is up to a volume fraction of 0.1 still mostly negligible.
Journal of Applied Physics, 1998
The extended two-particle model for statistical interactions in particle beams, developed by Jans... more The extended two-particle model for statistical interactions in particle beams, developed by Jansen [Coulomb Interactions in Particle Beams (Academic, Boston, 1990)], has been refined to improve the accuracy of the predictions of the trajectory displacement effect in particle beam ...
Optik, 1983
On discute sur l'influence des interactions entre des electrons individuels sur la qualite du... more On discute sur l'influence des interactions entre des electrons individuels sur la qualite du faisceau. Les aspects statistiques et dynamiques du grand nombre de particules sont reduits a un probleme a deux particules. L'effet de Boersch et le deplacement trajectoire sont calcules pour une geometrie simple
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1987
A fast algorithm for the ray tracing of an ensemble of interacting charged particles in drift spa... more A fast algorithm for the ray tracing of an ensemble of interacting charged particles in drift space has been developed for a fast Monte Carlo simulation program. It is based on a decomposition of the full interaction into a sum of two particle effects, which are estimated by means of analytical results. It is demonstrated that the reduction to two particle dynamics is allowed for practical beams used in lithography and microscopy, without decreasing the accuracy of the simulation. The new algorithm is up to two orders of magnitude faster (depending on the specific beam considered) than the algorithm using third order numerical integration with a variable time step. The program can be used on a fast microcomputer keeping the run time within practical limits.
International Journal of Multiphase Flow, 2000
A physical model for the dynamics of a dispersion of solid spherical particles in an incompressib... more A physical model for the dynamics of a dispersion of solid spherical particles in an incompressible viscous¯uid is outlined and used to calculate the turbulence modulation in a stationary, homogeneous and isotropic turbulent¯ow with particles. Starting from a postulated¯uid turbulence spectrum in the absence of particles, the physical model predicts the corresponding¯uid turbulence spectrum in the presence of particles and the particles turbulence spectrum as function of frequency and wavenumber. There are two versions of the model. The ®rst one uses a point-force approximation for the particles and takes into account the hydrodynamic interaction between the particles. The second version accounts for the detailed¯ow around the (®nite-diameter) particles, but does not consider their hydrodynamic interaction. The spectra, calculated with the two versions, are used to determine the turbulence intensity of the¯uid and particles as function of three relevant dimensionless groups. It is found that in general the dierences between the results of the point-particle model and the ®nite-diameter-particle model are signi®cant. So one has to be careful with point-particle models. The eect of the hydrodynamic interaction between the particles is up to a volume fraction of 0.1 still mostly negligible.
Journal of Applied Physics, 1998
The extended two-particle model for statistical interactions in particle beams, developed by Jans... more The extended two-particle model for statistical interactions in particle beams, developed by Jansen [Coulomb Interactions in Particle Beams (Academic, Boston, 1990)], has been refined to improve the accuracy of the predictions of the trajectory displacement effect in particle beam ...