IPAC2022 - Classification: MC7: Accelerator Technology / T16: Pulsed Power Technology

Paper	Title	Page
THPOST040	Commissioning of an X-Band Cavity for Longitudinal Phase Space Linearization at UCLA PEGASUS Laboratory	2533
	P.E. Denham, P. Musumeci, A. Ody UCLA, Los Angeles, USA
	This paper discusses the commissioning of an X-band (9.6 Ghz) linearizer cavity at the UCLA PEGASUS beamline. The photoinjector gun and booster linac operate at S-band (2.856 GHz) and the linearizer cavity can be used to compensate temporally correlated energy spread inherited by the use of relatively long (many ps) laser pulses at the photocathode. The cavity is comprised of 7 cells for a total length of a 9.45 cm, and is installed in the drift section between the gun and the linac. It can be used to remove higher order correlations and minimize the beam energy spread of 13 ps long beams to 10^-4.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST040
About •	Received ※ 08 June 2022 — Revised ※ 21 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 27 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK015	Solid-State Pulsed Power Supply for a 100 keV Electron Source of the New Synchrotron Facility in Thailand	2803
	W. Phacheerak, S. Bootiew, T. Chanwattana, Ch. Dhammatong, N. Juntong, K. Kittimanapun SLRI, Nakhon Ratchasima, Thailand K. Manasatitpong Synchrotron Light Research Institute (SLRI), Muang District, Thailand
	The new synchrotron light source project in Thailand will utilize a thermionic DC electron gun. The maximum operation of the gun is 100 keV, which requires a pulsed power supply of 100kV. The present synchrotron machine uses a conventional design of the gun power supply. To improve the high voltage pulsed quality, the solid-state design of the gun power supply is utilized. The output pulse width can be adjusted easily and the droop is less compared to the conventional design. The designed output of 100 kV amplitude with 5 µs pulsed width can be achieved with this design. It also produces a less droop of 1.8%. The design process and results will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK015
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK040	Few-Nanosecond Stripline Kickers for Top-Up Injection into PETRA IV	2858
	G. Loisch, V. Belokurov, F. Obier DESY, Hamburg, Germany
	PETRA IV is the planned ultralow-emittance upgrade of the PETRA III synchrotron light source at DESY, Hamburg. The current baseline injection scheme is an off-axis, top-up injection with few-nanosecond stripline kickers, which would allow for accumulation and least disturbance of experiments during injection. Besides the requirements on kick-strength, field quality, pulse rise-rate, and heat management, two mechanical designs with different apertures are necessary, as the devices will be used for injection and the transverse multi-bunch feedback system. In this contribution we will present the current status of 3D finite element simulations of electromagnetic fields and heating as well as the mechanical design and first pulse electronics tests.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK040
About •	Received ※ 20 May 2022 — Revised ※ 17 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 29 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK041	Development of Programmable Bipolar Multi kHz Kicker Drivers for Long Pulse Superconducting Electron Linacs	2862
	J.L. Teichgräber, W. Decking, J. Kahl, F. Obier DESY, Hamburg, Germany
	Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany Superconducting cavities allow for long rf-pulses, which enable the acceleration of thousands of electron bunches within one rf-pulse. Due to transient effects, e.g. coupler kicks, eddy currents or wakefields, bunch properties like the beam trajectory can change along the pulse train. To compensate for this, kicker systems based on high-current operational amplifiers have been developed for the free electron lasers European XFEL and FLASH at DESY in Hamburg. Here, we present the layout of the kicker system, the setup of the pulse electronics, and operational results with beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK041
About •	Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 19 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK042	Non-Linear Phenomena Studies in High-Gradient RF Technology for Hadrontherapy at IFIC	2865
SUSPMF117	use link to see paper's listing under its alternate paper code
	P.M.R. Martinez-Reviriego, C. Blanch Gutiérrez, D. Esperante Pereira, J. Fuster, N. Fuster-Martínez, B. Gimeno, D. Gonzalez-Iglesias, P. Martín-Luna IFIC, Valencia, Spain
	High-Gradient accelerating cavities are one of the main research lines in the development of compact linear colliders. However, the operation of such cavities is currently limited by non-linear effects that are intensified at high electric fields, such as dark currents and radiation emission or RF breakdowns. A new normal-conducting High Gradient S-band Backward Travelling Wave accelerating cavity for medical application (v=0.38c) designed and constructed at CERN is being tested at IFIC. In this paper, we present experimental measurements and simulation of such non-linear effects. The main goal of these studies is to establish the viability of using these techniques in linear accelerators, in order to improve our understanding in such effects. The main goal of these studies is to determine the viability of using this techniques in linear accelerators for hadrontherapy treatments in hospitals.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK042
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK043	Mitigation of High Voltage Breakdown of the Beam Screen of a CERN SPS Injection Kicker Magnet	2868
	M.J. Barnes, W. Bartmann, M. Díaz Zumel, L. Ducimetière, L.M.C. Feliciano, T. Kramer, V. Namora, T. Stadlbauer, D. Standen, P. Trubacova, F.M. Velotti, C. Zannini CERN, Meyrin, Switzerland
	The SPS injection kicker magnets (MKP) were developed in the 1970’s, before beam induced power deposition was considered an issue. These magnets are very lossy from a beam impedance perspective: this is expected to be an issue during SPS operation with the higher intensity beams needed for HL-LHC. A design, with serigraphy applied to an alumina carrier, has been developed to significantly reduce the broadband beam coupling impedance and hence mitigate the heating issues. During high voltage pulse testing there were electrical discharges associated with the serigraphy. Detailed mathematical models have been developed to aid in understanding the transiently induced voltages and to reduce the magnitude and duration of electric field. In this paper, we discuss the solutions implemented to mitigate the electrical discharges while maintaining an adequately low beam-coupling impedance. In addition, the results of high voltage tests are reported. The alumina substrate has a high secondary electron yield and thus electron-cloud could be an issue, with SPS beam, if mitigating measures were not taken: this paper also discusses the measures implemented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK043
About •	Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK044	Ultra-Fast Generator for Impact Ionization Triggering	2872
	A.A. del Barrio Montañés, Y. Dutheil, T. Kramer, V. Senaj CERN, Meyrin, Switzerland M. Sack KIT, Karlsruhe, Germany
	Impact ionization triggering can be successfully applied to standard thyristors, thus boosting their dI/dt capability by up to 1000x. This groundbreaking triggering requires applying significant overvoltage on the anode-cathode of thyristor with a slew rate > 1kV/ns. Compact pulse generators based on commercial off-the-shelf (COTS) components would allow the spread of this technology into numerous applications, including fast kicker generators for particle accelerators. In our approach, the beginning of the triggering chain is a HV SiC MOS with an ultra-fast super-boosting gate driver. The super boosting of a 1.7kV rated SiC MOS allows to reduce the MOS rise time by a factor of > 25 (datasheet tr = §I{20}{ns} vs. measured tr < 800ps, resulting in an output voltage slew rate > 1kV/ns and an amplitude > 1kV. Additional boosting is obtained by a Marx generator with GaAs diodes, reaching an output voltage slew rate > 11kV/ns. The final stage will be a Marx generator with medium size thyristors triggered in impact ionization mode with sufficient voltage and current rating necessary for the triggering of a big thyristor. This paper presents the impact ionization triggering of a small size thyristor.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK044
About •	Received ※ 16 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 06 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK045	Branch Module for an Inductive Voltage Adder for Driving Kicker Magnets with a Short Circuit Termination	2875
	J. Ruf, M.J. Barnes, Y. Dutheil, T. Kramer CERN, Meyrin, Switzerland M. Sack KIT, Karlsruhe, Germany
	For driving kicker magnets terminated in a short circuit, a branch module for an inductive voltage adder has been designed and assembled. The module has been designed for a maximum charging voltage of 1.2 kV and an output current of 200 A considering the current doubling due to the short circuit termination. It features three consecutive modes of operation: energy injection, freewheeling, and energy extraction. Therefore, the topology of the branch module consists of two independently controlled SiC MOSFET switches and one diode switch. In order not to extend the field rise time of the kicker magnet significantly beyond the magnet fill time, the pulse must have a fast rise time. Hence, the switch for energy injection is driven by a gate boosting driver featuring a half bridge of GaN HEMTs and a driving voltage of 80 V. Measurements of the drain source voltage of this switch showed a fall time of 2.7 ns at a voltage of 600 V resulting in a voltage rise time of 5.4 ns at the output terminated with a resistive load. To meet both the rise time and current requirements, a parallel configuration of four SiC MOSFETs was implemented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK045
About •	Received ※ 16 May 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Commissioning of an X-Band Cavity for Longitudinal Phase Space Linearization at UCLA PEGASUS Laboratory

2533

P.E. Denham, P. Musumeci, A. Ody
UCLA, Los Angeles, USA

This paper discusses the commissioning of an X-band (9.6 Ghz) linearizer cavity at the UCLA PEGASUS beamline. The photoinjector gun and booster linac operate at S-band (2.856 GHz) and the linearizer cavity can be used to compensate temporally correlated energy spread inherited by the use of relatively long (many ps) laser pulses at the photocathode. The cavity is comprised of 7 cells for a total length of a 9.45 cm, and is installed in the drift section between the gun and the linac. It can be used to remove higher order correlations and minimize the beam energy spread of 13 ps long beams to 10^-4.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST040

About •

Received ※ 08 June 2022 — Revised ※ 21 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 27 June 2022

Cite •

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

THPOTK015

Solid-State Pulsed Power Supply for a 100 keV Electron Source of the New Synchrotron Facility in Thailand

2803

W. Phacheerak, S. Bootiew, T. Chanwattana, Ch. Dhammatong, N. Juntong, K. Kittimanapun
SLRI, Nakhon Ratchasima, Thailand
K. Manasatitpong
Synchrotron Light Research Institute (SLRI), Muang District, Thailand

The new synchrotron light source project in Thailand will utilize a thermionic DC electron gun. The maximum operation of the gun is 100 keV, which requires a pulsed power supply of 100kV. The present synchrotron machine uses a conventional design of the gun power supply. To improve the high voltage pulsed quality, the solid-state design of the gun power supply is utilized. The output pulse width can be adjusted easily and the droop is less compared to the conventional design. The designed output of 100 kV amplitude with 5 µs pulsed width can be achieved with this design. It also produces a less droop of 1.8%. The design process and results will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK015

About •

Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022

Cite •

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

THPOTK040

Few-Nanosecond Stripline Kickers for Top-Up Injection into PETRA IV

2858

G. Loisch, V. Belokurov, F. Obier
DESY, Hamburg, Germany

PETRA IV is the planned ultralow-emittance upgrade of the PETRA III synchrotron light source at DESY, Hamburg. The current baseline injection scheme is an off-axis, top-up injection with few-nanosecond stripline kickers, which would allow for accumulation and least disturbance of experiments during injection. Besides the requirements on kick-strength, field quality, pulse rise-rate, and heat management, two mechanical designs with different apertures are necessary, as the devices will be used for injection and the transverse multi-bunch feedback system. In this contribution we will present the current status of 3D finite element simulations of electromagnetic fields and heating as well as the mechanical design and first pulse electronics tests.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK040

About •

Received ※ 20 May 2022 — Revised ※ 17 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 29 June 2022

Cite •

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

THPOTK041

Development of Programmable Bipolar Multi kHz Kicker Drivers for Long Pulse Superconducting Electron Linacs

2862

J.L. Teichgräber, W. Decking, J. Kahl, F. Obier
DESY, Hamburg, Germany

Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany Superconducting cavities allow for long rf-pulses, which enable the acceleration of thousands of electron bunches within one rf-pulse. Due to transient effects, e.g. coupler kicks, eddy currents or wakefields, bunch properties like the beam trajectory can change along the pulse train. To compensate for this, kicker systems based on high-current operational amplifiers have been developed for the free electron lasers European XFEL and FLASH at DESY in Hamburg. Here, we present the layout of the kicker system, the setup of the pulse electronics, and operational results with beam.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK041

About •

Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 19 June 2022

Cite •

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

THPOTK042

Non-Linear Phenomena Studies in High-Gradient RF Technology for Hadrontherapy at IFIC

2865

SUSPMF117

use link to see paper's listing under its alternate paper code

P.M.R. Martinez-Reviriego, C. Blanch Gutiérrez, D. Esperante Pereira, J. Fuster, N. Fuster-Martínez, B. Gimeno, D. Gonzalez-Iglesias, P. Martín-Luna
IFIC, Valencia, Spain

High-Gradient accelerating cavities are one of the main research lines in the development of compact linear colliders. However, the operation of such cavities is currently limited by non-linear effects that are intensified at high electric fields, such as dark currents and radiation emission or RF breakdowns. A new normal-conducting High Gradient S-band Backward Travelling Wave accelerating cavity for medical application (v=0.38c) designed and constructed at CERN is being tested at IFIC. In this paper, we present experimental measurements and simulation of such non-linear effects. The main goal of these studies is to establish the viability of using these techniques in linear accelerators, in order to improve our understanding in such effects. The main goal of these studies is to determine the viability of using this techniques in linear accelerators for hadrontherapy treatments in hospitals.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK042

About •

Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022

Cite •

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

THPOTK043

Mitigation of High Voltage Breakdown of the Beam Screen of a CERN SPS Injection Kicker Magnet

2868

M.J. Barnes, W. Bartmann, M. Díaz Zumel, L. Ducimetière, L.M.C. Feliciano, T. Kramer, V. Namora, T. Stadlbauer, D. Standen, P. Trubacova, F.M. Velotti, C. Zannini
CERN, Meyrin, Switzerland

The SPS injection kicker magnets (MKP) were developed in the 1970’s, before beam induced power deposition was considered an issue. These magnets are very lossy from a beam impedance perspective: this is expected to be an issue during SPS operation with the higher intensity beams needed for HL-LHC. A design, with serigraphy applied to an alumina carrier, has been developed to significantly reduce the broadband beam coupling impedance and hence mitigate the heating issues. During high voltage pulse testing there were electrical discharges associated with the serigraphy. Detailed mathematical models have been developed to aid in understanding the transiently induced voltages and to reduce the magnitude and duration of electric field. In this paper, we discuss the solutions implemented to mitigate the electrical discharges while maintaining an adequately low beam-coupling impedance. In addition, the results of high voltage tests are reported. The alumina substrate has a high secondary electron yield and thus electron-cloud could be an issue, with SPS beam, if mitigating measures were not taken: this paper also discusses the measures implemented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK043

About •

Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022

Cite •

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

THPOTK044

Ultra-Fast Generator for Impact Ionization Triggering

2872

A.A. del Barrio Montañés, Y. Dutheil, T. Kramer, V. Senaj
CERN, Meyrin, Switzerland
M. Sack
KIT, Karlsruhe, Germany

Impact ionization triggering can be successfully applied to standard thyristors, thus boosting their dI/dt capability by up to 1000x. This groundbreaking triggering requires applying significant overvoltage on the anode-cathode of thyristor with a slew rate > 1kV/ns. Compact pulse generators based on commercial off-the-shelf (COTS) components would allow the spread of this technology into numerous applications, including fast kicker generators for particle accelerators. In our approach, the beginning of the triggering chain is a HV SiC MOS with an ultra-fast super-boosting gate driver. The super boosting of a 1.7kV rated SiC MOS allows to reduce the MOS rise time by a factor of > 25 (datasheet tr = §I{20}{ns} vs. measured tr < 800ps, resulting in an output voltage slew rate > 1kV/ns and an amplitude > 1kV. Additional boosting is obtained by a Marx generator with GaAs diodes, reaching an output voltage slew rate > 11kV/ns. The final stage will be a Marx generator with medium size thyristors triggered in impact ionization mode with sufficient voltage and current rating necessary for the triggering of a big thyristor. This paper presents the impact ionization triggering of a small size thyristor.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK044

About •

Received ※ 16 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 06 July 2022

Cite •

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

THPOTK045

Branch Module for an Inductive Voltage Adder for Driving Kicker Magnets with a Short Circuit Termination

2875

J. Ruf, M.J. Barnes, Y. Dutheil, T. Kramer
CERN, Meyrin, Switzerland
M. Sack
KIT, Karlsruhe, Germany

For driving kicker magnets terminated in a short circuit, a branch module for an inductive voltage adder has been designed and assembled. The module has been designed for a maximum charging voltage of 1.2 kV and an output current of 200 A considering the current doubling due to the short circuit termination. It features three consecutive modes of operation: energy injection, freewheeling, and energy extraction. Therefore, the topology of the branch module consists of two independently controlled SiC MOSFET switches and one diode switch. In order not to extend the field rise time of the kicker magnet significantly beyond the magnet fill time, the pulse must have a fast rise time. Hence, the switch for energy injection is driven by a gate boosting driver featuring a half bridge of GaN HEMTs and a driving voltage of 80 V. Measurements of the drain source voltage of this switch showed a fall time of 2.7 ns at a voltage of 600 V resulting in a voltage rise time of 5.4 ns at the output terminated with a resistive load. To meet both the rise time and current requirements, a parallel configuration of four SiC MOSFETs was implemented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK045

About •

Received ※ 16 May 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022

Cite •

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