Cyclotrons2019 - List of Authors (Frey, M.)

Paper	Title	Page
MOP034	Beam Stripping Interactions Implemented in Cyclotrons with OPAL Simulation Code	109
	P. Calvo, C. Oliver CIEMAT, Madrid, Spain A. Adelmann, M. Frey, A. Gsell, J. Snuverink PSI, Villigen PSI, Switzerland
	Beam transmission optimization and losses characterization, where beam stripping interactions are a key issue, play an important role in the design and operation of compact cyclotrons. A beam stripping model has been implemented in the three-dimensional object-oriented parallel code OPAL-cycl, a flavor of the OPAL framework. The model includes Monte Carlo methods for interaction with residual gas and dissociation by electromagnetic stripping. The model has been verified with theoretical models and it has been applied to the AMIT cyclotron according to design conditions.
	Poster MOP034 [0.880 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-MOP034
About •	paper received ※ 12 September 2019 paper accepted ※ 26 September 2019 issue date ※ 20 June 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA01	Precise Modelling and Large Scale Multiobjective Optimisation of Cyclotrons	284
	J. Snuverink, A. Adelmann, C. Baumgarten, M. Frey PSI, Villigen PSI, Switzerland
	The usage of numerical models to study the evolution of particle beams is an essential step in the design process of particle accelerators. However, uncertainties of input quantities such as beam energy and magnetic field lead to simulation results that do not fully agree with measurements. Hence the machine will behave differently compared to the simulations. In case of cyclotrons such discrepancies affect the overall turn pattern or alter the number of turns. Inaccuracies at the PSI Ring cyclotron that may harm the isochronicity are compensated by 18 trim coils. Trim coils are often absent in simulations or their implementation is simplistic. A realistic trim coil model within the simulation framework OPAL is presented. It was used to match the turn pattern of the PSI Ring. Due to the high-dimensional search space consisting of 48 simulation input parameters and 182 objectives (i.e. turns) simulation and measurement cannot be matched in a straightforward manner. Instead, an evolutionary multi-objective optimisation with more than 8000 simulations per iteration together with a local search approach was applied that reduced the maximum error to 4.5 mm over all 182 turns.
	Slides THA01 [6.834 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-THA01
About •	paper received ※ 25 September 2019 paper accepted ※ 27 September 2019 issue date ※ 20 June 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Stripping Interactions Implemented in Cyclotrons with OPAL Simulation Code

109

P. Calvo, C. Oliver
CIEMAT, Madrid, Spain
A. Adelmann, M. Frey, A. Gsell, J. Snuverink
PSI, Villigen PSI, Switzerland

Beam transmission optimization and losses characterization, where beam stripping interactions are a key issue, play an important role in the design and operation of compact cyclotrons. A beam stripping model has been implemented in the three-dimensional object-oriented parallel code OPAL-cycl, a flavor of the OPAL framework. The model includes Monte Carlo methods for interaction with residual gas and dissociation by electromagnetic stripping. The model has been verified with theoretical models and it has been applied to the AMIT cyclotron according to design conditions.

Poster MOP034 [0.880 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-MOP034

About •

paper received ※ 12 September 2019 paper accepted ※ 26 September 2019 issue date ※ 20 June 2020

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THA01

Precise Modelling and Large Scale Multiobjective Optimisation of Cyclotrons

284

J. Snuverink, A. Adelmann, C. Baumgarten, M. Frey
PSI, Villigen PSI, Switzerland

The usage of numerical models to study the evolution of particle beams is an essential step in the design process of particle accelerators. However, uncertainties of input quantities such as beam energy and magnetic field lead to simulation results that do not fully agree with measurements. Hence the machine will behave differently compared to the simulations. In case of cyclotrons such discrepancies affect the overall turn pattern or alter the number of turns. Inaccuracies at the PSI Ring cyclotron that may harm the isochronicity are compensated by 18 trim coils. Trim coils are often absent in simulations or their implementation is simplistic. A realistic trim coil model within the simulation framework OPAL is presented. It was used to match the turn pattern of the PSI Ring. Due to the high-dimensional search space consisting of 48 simulation input parameters and 182 objectives (i.e. turns) simulation and measurement cannot be matched in a straightforward manner. Instead, an evolutionary multi-objective optimisation with more than 8000 simulations per iteration together with a local search approach was applied that reduced the maximum error to 4.5 mm over all 182 turns.

Slides THA01 [6.834 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-THA01

About •

paper received ※ 25 September 2019 paper accepted ※ 27 September 2019 issue date ※ 20 June 2020

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)