Cyclotrons2019 - List of Keywords (bunching)

Paper	Title	Other Keywords	Page
MOP022	Project of a Novel Multi-Orbital Beam Bunching and Extraction from the U-120M Cyclotron	cyclotron, target, neutron, extraction	80
	M. Čihák, R. Běhal, P. Krist, T. Matlocha, J. Stursa, V. Zach NPI, Řež near Prague, Czech Republic
	We introduce the bunching system for a time structure control of the U-120M cyclotron beam. The system is based on a unique pulsed vertical deflection of the selected final orbits of the internal accelerated beam of the H⁻ ions to an extractor-stripper (a thin carbon foil positioned below the cyclotron median plane). A set of home-made programs have been developed for simulations and parameters determination of the system. Results of some simulations (i.e. dimensions of the deflection system, parameters of the pulsed high voltage power supply, position of the stripper, beam trajectories, beam parameters, beam losses, Be target position etc.) are presented. The system will be used for fast neutron generation and consequently for spectrometric measurement of neutron energy by the time of flight (ToF) method. The system will provide beam bunch interval up to 1000 ns range of a defined beam time structure (up to beam bunch period to beam bunch width ratio min 100).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-MOP022
About •	paper received ※ 15 September 2019 paper accepted ※ 25 September 2019 issue date ※ 20 June 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOP023	Synchronization and High Speed High Voltage Switcher for Pulse Bunching System of the Cyclotron U-120M	cyclotron, neutron, proton, PLC	83
	P. Krist, D. Poklop, J. Stursa NPI, Řež near Prague, Czech Republic V. Cervenka HiLASE Centre, Institute of Physics ASCR, v.v.i., Dolní BřeÂany, Czech Republic J. Vozáb Radan s.r.o., Barchov, Czech Republic
	Pulse bunching system for neutron time of flight (ToF) measurements on the cyclotron U-120M exploits a unique pulsed vertical deflection of the selected final orbits of the internal accelerated beam of the H⁻ ions to an extractor-stripper. This system is described in details on an individual poster of this conference. A key device is the pulse HV power supply (HV switcher) which is supplying the deflector and elevates H⁻ ions in defined time structure to an extractor-stripper. The developed HV switcher is based on the SiC MOSFET transistors. It can provide HV pulses with the following pulse parameters: amplitude up to 13 kV, front edge less than 20 ns, flat top 20 ns, back edge less than 20 ns and repetition frequency up to several hundred of kHz. We have also developed the pulse synchronization with the cyclotron RF (25 MHz), which enables to set up front edge of bunching pulses within 2pi with accuracy 80 ps. Human-machine interface is based on SCADA software Reliance and PLC Tecomat Foxtrot. The time waveforms of the real pulses are part of the presentation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-MOP023
About •	paper received ※ 15 September 2019 paper accepted ※ 25 September 2019 issue date ※ 20 June 2020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEB03	Factors Influencing the Vortex Effect in High-Intensity Cyclotrons	cyclotron, space-charge, acceleration, simulation	270
	C. Baumgarten PSI, Villigen PSI, Switzerland
	We discuss factors that have potential influence on the space charge induced vortex motion of particles within high intensity bunches (curling of bunches, Gordon 1969) in isochronous cyclotrons. The influence of the phase slip due to deviations from strict isochronism determines if the bunches of a specific turn are above, below or at "transition", and hence whether stable vortex motion of the bunches is possible at all. Secondly there are possible longitudinal and transverse effects of rf acceleration, the former depending on the bunch phase ("bunching" or "debunching"), the latter depending on the gradient of the accelerating voltage. High accelerating voltages in the first turns call the applicability of adiabatic approximations and analytic methods into question. The influence of the rf acceleration is expected to be significant only at low beam energy, i.e. should have small or even negligible effect beyond the central region of compact machines.
	Slides WEB03 [1.145 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-WEB03
About •	paper received ※ 16 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)

Paper

Title

Other Keywords

Page

MOP022

Project of a Novel Multi-Orbital Beam Bunching and Extraction from the U-120M Cyclotron

cyclotron, target, neutron, extraction

80

M. Čihák, R. Běhal, P. Krist, T. Matlocha, J. Stursa, V. Zach
NPI, Řež near Prague, Czech Republic

We introduce the bunching system for a time structure control of the U-120M cyclotron beam. The system is based on a unique pulsed vertical deflection of the selected final orbits of the internal accelerated beam of the H⁻ ions to an extractor-stripper (a thin carbon foil positioned below the cyclotron median plane). A set of home-made programs have been developed for simulations and parameters determination of the system. Results of some simulations (i.e. dimensions of the deflection system, parameters of the pulsed high voltage power supply, position of the stripper, beam trajectories, beam parameters, beam losses, Be target position etc.) are presented. The system will be used for fast neutron generation and consequently for spectrometric measurement of neutron energy by the time of flight (ToF) method. The system will provide beam bunch interval up to 1000 ns range of a defined beam time structure (up to beam bunch period to beam bunch width ratio min 100).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-MOP022

About •

paper received ※ 15 September 2019 paper accepted ※ 25 September 2019 issue date ※ 20 June 2020

Export •

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

MOP023

Synchronization and High Speed High Voltage Switcher for Pulse Bunching System of the Cyclotron U-120M

cyclotron, neutron, proton, PLC

83

P. Krist, D. Poklop, J. Stursa
NPI, Řež near Prague, Czech Republic
V. Cervenka
HiLASE Centre, Institute of Physics ASCR, v.v.i., Dolní BřeÂany, Czech Republic
J. Vozáb
Radan s.r.o., Barchov, Czech Republic

Pulse bunching system for neutron time of flight (ToF) measurements on the cyclotron U-120M exploits a unique pulsed vertical deflection of the selected final orbits of the internal accelerated beam of the H⁻ ions to an extractor-stripper. This system is described in details on an individual poster of this conference. A key device is the pulse HV power supply (HV switcher) which is supplying the deflector and elevates H⁻ ions in defined time structure to an extractor-stripper. The developed HV switcher is based on the SiC MOSFET transistors. It can provide HV pulses with the following pulse parameters: amplitude up to 13 kV, front edge less than 20 ns, flat top 20 ns, back edge less than 20 ns and repetition frequency up to several hundred of kHz. We have also developed the pulse synchronization with the cyclotron RF (25 MHz), which enables to set up front edge of bunching pulses within 2pi with accuracy 80 ps. Human-machine interface is based on SCADA software Reliance and PLC Tecomat Foxtrot. The time waveforms of the real pulses are part of the presentation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-MOP023

About •

paper received ※ 15 September 2019 paper accepted ※ 25 September 2019 issue date ※ 20 June 2020

Export •

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

WEB03

Factors Influencing the Vortex Effect in High-Intensity Cyclotrons

cyclotron, space-charge, acceleration, simulation

270

C. Baumgarten
PSI, Villigen PSI, Switzerland

We discuss factors that have potential influence on the space charge induced vortex motion of particles within high intensity bunches (curling of bunches, Gordon 1969) in isochronous cyclotrons. The influence of the phase slip due to deviations from strict isochronism determines if the bunches of a specific turn are above, below or at "transition", and hence whether stable vortex motion of the bunches is possible at all. Secondly there are possible longitudinal and transverse effects of rf acceleration, the former depending on the bunch phase ("bunching" or "debunching"), the latter depending on the gradient of the accelerating voltage. High accelerating voltages in the first turns call the applicability of adiabatic approximations and analytic methods into question. The influence of the rf acceleration is expected to be significant only at low beam energy, i.e. should have small or even negligible effect beyond the central region of compact machines.

Slides WEB03 [1.145 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-Cyclotrons2019-WEB03

About •

paper received ※ 16 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)