IPAC2021 - List of Authors (Kramer, T.)

Paper	Title	Page
TUPAB363	Feasibility Study for the Novel CERN PS Fast Extraction Septum	2363
	T. Helseth, M.G. Atanasov, B. Balhan, J.C.C.M. Borburgh, L. Ducimetière, M.A. Fraser, T. Kramer CERN, Geneva, Switzerland
	In the framework of accelerator consolidation, a feasibility study for a novel CERN PS extraction septum has been conducted. Functional requirements have been established and, accordingly, a system of two septa magnets and their associated pulse generator is proposed. The magnetic septum design is based on eddy current topology. Magnetic simulations in Flux 2D and Opera 3D of a conceptual design have been carried out. The short length and high amplitude of the current pulse required to drive the eddy current septa imply that none of the power converters currently used for septa magnets at CERN will be suitable. Pulse generator topologies derived from kicker generators have therefore been explored and simulated in Spice. The conceptual magnet and generator design along with simulation results are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB363
About •	paper received ※ 18 May 2021 paper accepted ※ 17 June 2021 issue date ※ 10 August 2021
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WEPAB343	Inductive Adder Prototype for FCC-hh Injection Kicker System	3494
	D. Woog, M.J. Barnes, T. Kramer CERN, Meyrin, Switzerland H. De Gersem TEMF, TU Darmstadt, Darmstadt, Germany
	The future circular collider (FCC) requires a highly reliable injection kicker system. Present day kicker systems often rely on thyratron-based pulse generators and a pulse forming network or line: the thyratron is susceptible to self-triggering. Hence, an alternative pulse generator topology, based on fast semiconductor switches, is considered for the FCC. One possibility is an inductive adder (IA). A prototype IA has been designed and built: the main challenges are the fast rise time, high output current, low system impedance and a 2.3 us pulse duration combined with low droop. This paper presents the results of measurements on the prototype IA where the rated output current and output voltage were achieved separately. Suggested improvements to the IA hardware are identified and proposals are presented that could help improve the kicker system performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB343
About •	paper received ※ 16 May 2021 paper accepted ※ 01 July 2021 issue date ※ 17 August 2021
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WEPAB347	Design, Construction and Testing of a Magnetic Probe for Fast Kicker Magnets	3510
	N. Ayala, A. Ferrero Colomo, T. Kramer CERN, Geneva 23, Switzerland
	The CERN PS injection kicker has been modified in the framework of the LHC Injector Upgrade (LIU) project to allow injecting proton beams with an energy of 2 GeV. One of the most important items of the system parameter validation is the measurement and analysis of the magnetic field in the magnet aperture. To meet the required measurement precision without compromising the magnet vacuum performance, a dedicated magnetic probe has been designed, constructed and tested. The results are presented in this paper highlighting the mitigations of electrical, mechanical and vacuum complications. The paper concludes with an analysis of the probe performance during the first magnetic field measurements in the laboratory.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB347
About •	paper received ※ 19 May 2021 paper accepted ※ 07 July 2021 issue date ※ 02 September 2021
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WEPAB351	Requirements for an Inductive Voltage Adder as Driver for a Kicker Magnet with Short Circuit Termination	3521
	J. Ruf, M.J. Barnes, T. Kramer CERN, Geneva 23, Switzerland M. Sack KIT, Karlsruhe, Germany
	At CERN pulse generators based on Thyratron switches and SF6 gas filled pulse forming lines, used for driving kicker magnets, are to be replaced with semiconductor technology. Preliminary investigations show the inductive voltage adder is suitable as a pulse generator for this application. To increase the magnetic field without raising the system voltage, a short-circuit termination is often applied to a kicker magnet. Because of the electrical length of a transmission line magnet, wave propagation needs to be considered. To allow for the wavefront reflected from the short-circuit termination back to the generator, a novel approach for an inductive adder architecture has been investigated. It is based on a modified generator interface, circulating the current back into the load, until the stored energy is absorbed at the end of the pulse. This approach allows for a smaller magnetic core size compared to a conventional design with a matched load. Moreover, it enables more energy-efficient operation involving smaller storage capacitors. This paper summarizes the conceptual design features and furthermore gives an overview of the parameter space for possible applications at CERN.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB351
About •	paper received ※ 18 May 2021 paper accepted ※ 11 June 2021 issue date ※ 17 August 2021
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THPAB340	Sub-Nanosecond Switching of HV SiC MOS Transistors for Impact Ionisation Triggering	4454
	V. Senaj, T. Kramer, A.A. del Barrio Montañés CERN, Geneva 23, Switzerland M. Sack KIT, Karlsruhe, Germany
	Pulse generators with multi kV/kA pulses are necessary for the particle accelerator environment for beam transfer magnets. Traditionally these generators are using thyratrons - until recently the only switches capable of switching such pulses within tens of ns. There is a strong demand to replace thyratrons with semiconductor switches to avoid their future obsolescence. Very promising candidates are components from the family of fast ionization dynistors triggered by impact ionization. Their sub-nanosecond switching time and extreme current densities can provide performances superior to that of thyratrons. Recent investigations showed that impact ionization triggering is feasible also in cheap industrial thyristors. The main issue is the generation of triggering pulses with slew rates in the multi kV/ns region and with the required output current for charging the parasitic capacitance of the thyristor. We present an approach of generating > 1 kV/ns pulses by ultra-boosted gate driving of HV SiC MOS transistors. We found that the MOS lifetime under these extreme triggering conditions can still reach more than 10⁸ pulses, enough for kicker generator applications.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB340
About •	paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 27 August 2021
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THPAB354	Deployment and Commissioning of the CERN PS Injection Kicker System for Operation with 2 GeV Beams in Short Circuit Mode	4489
	T. Kramer, N. Ayala, J.C.C.M. Borburgh, P.A.H. Burkel, E. Carlier, L. Ducimetière, L.M.C. Feliciano, A. Ferrero Colomo, M.A. Fraser, L.A. Govertsen, R. Noulibos, S. Pavis, L. Sermeus CERN, Geneva, Switzerland
	Within the framework of the LHC Injector Upgrade (LIU) project, the feasibility and design of an upgrade of the existing CERN PS proton injection kicker system have been outlined in previous publications already. This paper describes the adjustments of final design choices, testing, and deployment as well as the validation and commissioning of the new 2 GeV injection kicker system. The upgrade pays particular attention to the reduction of pulse reflections unavoidably induced by a magnet in short circuit mode configuration whilst keeping a fast 10⁴ ns rise and fall time. An adapted thyratron triggering system to reduce jitter and enhance thyratron lifetime is outlined. Additionally, improvements to the magnet entry box and the elimination of SF6 gas in the magnet connection box and the associated pulse transmission lines are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB354
About •	paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 10 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Feasibility Study for the Novel CERN PS Fast Extraction Septum

2363

T. Helseth, M.G. Atanasov, B. Balhan, J.C.C.M. Borburgh, L. Ducimetière, M.A. Fraser, T. Kramer
CERN, Geneva, Switzerland

In the framework of accelerator consolidation, a feasibility study for a novel CERN PS extraction septum has been conducted. Functional requirements have been established and, accordingly, a system of two septa magnets and their associated pulse generator is proposed. The magnetic septum design is based on eddy current topology. Magnetic simulations in Flux 2D and Opera 3D of a conceptual design have been carried out. The short length and high amplitude of the current pulse required to drive the eddy current septa imply that none of the power converters currently used for septa magnets at CERN will be suitable. Pulse generator topologies derived from kicker generators have therefore been explored and simulated in Spice. The conceptual magnet and generator design along with simulation results are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB363

About •

paper received ※ 18 May 2021 paper accepted ※ 17 June 2021 issue date ※ 10 August 2021

Export •

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

WEPAB343

Inductive Adder Prototype for FCC-hh Injection Kicker System

3494

D. Woog, M.J. Barnes, T. Kramer
CERN, Meyrin, Switzerland
H. De Gersem
TEMF, TU Darmstadt, Darmstadt, Germany

The future circular collider (FCC) requires a highly reliable injection kicker system. Present day kicker systems often rely on thyratron-based pulse generators and a pulse forming network or line: the thyratron is susceptible to self-triggering. Hence, an alternative pulse generator topology, based on fast semiconductor switches, is considered for the FCC. One possibility is an inductive adder (IA). A prototype IA has been designed and built: the main challenges are the fast rise time, high output current, low system impedance and a 2.3 us pulse duration combined with low droop. This paper presents the results of measurements on the prototype IA where the rated output current and output voltage were achieved separately. Suggested improvements to the IA hardware are identified and proposals are presented that could help improve the kicker system performance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB343

About •

paper received ※ 16 May 2021 paper accepted ※ 01 July 2021 issue date ※ 17 August 2021

Export •

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

WEPAB347

Design, Construction and Testing of a Magnetic Probe for Fast Kicker Magnets

3510

N. Ayala, A. Ferrero Colomo, T. Kramer
CERN, Geneva 23, Switzerland

The CERN PS injection kicker has been modified in the framework of the LHC Injector Upgrade (LIU) project to allow injecting proton beams with an energy of 2 GeV. One of the most important items of the system parameter validation is the measurement and analysis of the magnetic field in the magnet aperture. To meet the required measurement precision without compromising the magnet vacuum performance, a dedicated magnetic probe has been designed, constructed and tested. The results are presented in this paper highlighting the mitigations of electrical, mechanical and vacuum complications. The paper concludes with an analysis of the probe performance during the first magnetic field measurements in the laboratory.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB347

About •

paper received ※ 19 May 2021 paper accepted ※ 07 July 2021 issue date ※ 02 September 2021

Export •

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

WEPAB351

Requirements for an Inductive Voltage Adder as Driver for a Kicker Magnet with Short Circuit Termination

3521

J. Ruf, M.J. Barnes, T. Kramer
CERN, Geneva 23, Switzerland
M. Sack
KIT, Karlsruhe, Germany

At CERN pulse generators based on Thyratron switches and SF6 gas filled pulse forming lines, used for driving kicker magnets, are to be replaced with semiconductor technology. Preliminary investigations show the inductive voltage adder is suitable as a pulse generator for this application. To increase the magnetic field without raising the system voltage, a short-circuit termination is often applied to a kicker magnet. Because of the electrical length of a transmission line magnet, wave propagation needs to be considered. To allow for the wavefront reflected from the short-circuit termination back to the generator, a novel approach for an inductive adder architecture has been investigated. It is based on a modified generator interface, circulating the current back into the load, until the stored energy is absorbed at the end of the pulse. This approach allows for a smaller magnetic core size compared to a conventional design with a matched load. Moreover, it enables more energy-efficient operation involving smaller storage capacitors. This paper summarizes the conceptual design features and furthermore gives an overview of the parameter space for possible applications at CERN.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB351

About •

paper received ※ 18 May 2021 paper accepted ※ 11 June 2021 issue date ※ 17 August 2021

Export •

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

THPAB340

Sub-Nanosecond Switching of HV SiC MOS Transistors for Impact Ionisation Triggering

4454

V. Senaj, T. Kramer, A.A. del Barrio Montañés
CERN, Geneva 23, Switzerland
M. Sack
KIT, Karlsruhe, Germany

Pulse generators with multi kV/kA pulses are necessary for the particle accelerator environment for beam transfer magnets. Traditionally these generators are using thyratrons - until recently the only switches capable of switching such pulses within tens of ns. There is a strong demand to replace thyratrons with semiconductor switches to avoid their future obsolescence. Very promising candidates are components from the family of fast ionization dynistors triggered by impact ionization. Their sub-nanosecond switching time and extreme current densities can provide performances superior to that of thyratrons. Recent investigations showed that impact ionization triggering is feasible also in cheap industrial thyristors. The main issue is the generation of triggering pulses with slew rates in the multi kV/ns region and with the required output current for charging the parasitic capacitance of the thyristor. We present an approach of generating > 1 kV/ns pulses by ultra-boosted gate driving of HV SiC MOS transistors. We found that the MOS lifetime under these extreme triggering conditions can still reach more than 10⁸ pulses, enough for kicker generator applications.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB340

About •

paper received ※ 18 May 2021 paper accepted ※ 01 July 2021 issue date ※ 27 August 2021

Export •

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

THPAB354

Deployment and Commissioning of the CERN PS Injection Kicker System for Operation with 2 GeV Beams in Short Circuit Mode

4489

T. Kramer, N. Ayala, J.C.C.M. Borburgh, P.A.H. Burkel, E. Carlier, L. Ducimetière, L.M.C. Feliciano, A. Ferrero Colomo, M.A. Fraser, L.A. Govertsen, R. Noulibos, S. Pavis, L. Sermeus
CERN, Geneva, Switzerland

Within the framework of the LHC Injector Upgrade (LIU) project, the feasibility and design of an upgrade of the existing CERN PS proton injection kicker system have been outlined in previous publications already. This paper describes the adjustments of final design choices, testing, and deployment as well as the validation and commissioning of the new 2 GeV injection kicker system. The upgrade pays particular attention to the reduction of pulse reflections unavoidably induced by a magnet in short circuit mode configuration whilst keeping a fast 10⁴ ns rise and fall time. An adapted thyratron triggering system to reduce jitter and enhance thyratron lifetime is outlined. Additionally, improvements to the magnet entry box and the elimination of SF6 gas in the magnet connection box and the associated pulse transmission lines are discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB354

About •

paper received ※ 19 May 2021 paper accepted ※ 14 July 2021 issue date ※ 10 August 2021

Export •

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