LINAC2016 - List of Keywords (klystron)

Paper	Title	Other Keywords	Page
MO1A02	Status of the European XFEL	linac, electron, undulator, operation	7
	H. Weise DESY, Hamburg, Germany
	Funding: Work supported by the respective funding agencies of the contributing institutes; for details please see http:www.xfel.eu The European XFEL under construction in Hamburg, Northern Germany, aims at producing X-rays in the range from 260 eV up to 24 keV out of three undulators that can be operated simultaneously with up to 27,000 pulses per second. The FEL is driven by a 17.5 GeV superconducting linac. Installation of this linac is now finished and commissioning is next. First lasing is expected for spring 2017. The paper summarizes the status of the project. First results of the injector commissioning are given.
	Slides MO1A02 [28.909 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MO1A02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOOP12	Klynac Design Simulations and Experimental Setup	cavity, linac, electron, simulation	68
	K.E. Nichols, B.E. Carlsten, A. Malyzhenkov LANL, Los Alamos, New Mexico, USA
	Funding: The authors gratefully acknowledge the support of the US Department of Energy through the LANL/LDRD Program for this work. We present results of a proof-of-principle demonstration of the first ever klynac, a compact 1 MeV linear accelerator with integrated klystron source using one electron beam. This device is bi-resonant, utilizing one resonant circuit for the klystron input and gain cavities, and one for the klystron output and linac cavities. The purpose of a klynac-type device is to provide a compact and inexpensive alternative for a conventional 1 to 6 MeV accelerator. A conventional accelerator requires a separate RF source and linac and all the associated hardware needed for that architecture. The klynac configuration eliminates many of the components to reduce the weight of the entire system by 60%. We have built an 8-cavity, 2.84-GHz RF structure for a 1-MeV bi-resonant klynac. A 50-kV, 10-A electron gun provides the single beam needed. Numerical modeling was used to optimize the design. The separation between the klynac ouput cavity and the first accelerator cavity was adjusted to optimize the bunch capture and a pin-hole aperture between the two cavities reduces the beam current in the linac section to about 0.1 A. Standard high-shunt impedance linac cavities designs are used. We have fabricated the first test structure. The structure will be tested with beam in early Summer 2016. Results will be presented at LINAC 2016.
	Slides MOOP12 [1.136 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOOP12
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPRC027	Surface Roughness Effect on the Performance of Nb3Sn Cavities	cavity, SRF, pulsed-power, niobium	129
	R.D. Porter, D.L. Hall, M. Liepe, J.T. Maniscalco Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: DOE award DE-SC0008431 Surface roughness of current Niobium-3 Tin (Nb3Sn) superconducting radio-frequency (SRF) accelerator cavities can cause enhancement of the surface magnetic field. This enhancement can push the surface magnetic field beyond the critical field, which, if it occurs over a large enough area, can cause the cavity to quench. This paper presents simulations of the surface magnetic field enhancements in SRF cavities caused by the surface roughness of current Cornell Nb3Sn cavities, which have achieved record efficiency. Simple, smooth cavity geometry is defined and surface magnetic fields calculated using SLANS2. The cavity geometry is modified with a small rough region for which the geometry is determined from AFM scans of a Nb3Sn coated sample and the surface fields are calculated again. The calculated surface fields of the smooth and rough cavities are compared to determine the extent of the field enhancement, the area over which the enhancement is significant, and which surface features cause large field enhancement. We find that 1% of the surface analyzed has fields enhance by more than 45%. On average the Q-factor is increased by (3.8 ± 1.0) \%.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC027
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPLR018	Upgrade of the Klystron Modulator of the L-Band Electron Linac at Osaka University for Higher Stability	resonance, impedance, linac, high-voltage	178
	K. Furukawa, G. Isoyama ISIR, Osaka, Japan R. Kato KEK, Ibaraki, Japan K. Kawase HSRC, Higashi-Hiroshima, Japan A. Tokuchi Pulsed Power Japan Laboratory Ltd., Kusatsu-shi Shiga, Japan
	The klystron modulator for the L-band linac is upgraded for higher stability. The two-step charging system for the pulse forming network (PFN) is upgraded by adding a high impedance resonant charging line in parallel with the main line. The charging step of the PFN voltage is reduced considerably near the setting value by switching the main resonance line off so that the charging current flows only through the high impedance line. The second model of the solid-state switch is developed using 60 static-induction thyristors, ten of which are connected in series with six such series connected in parallel to meet maximum specifications of 25 kV and 6 kA. The air-cooling capacity is reinforced so that repetition rate is increased from 10 pps for the first model to 60 pps. The fluctuation and accuracy of the klystron voltage are measured to be 7.8×10^-6 or 7.8 ppm for the upgraded klystron modulator using a differential amplifier with much higher sensitivity than one used in the previous measurement.
	Poster MOPLR018 [0.840 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR018
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPLR065	High-Gradient X-band Structures for Proton Energy Booster at LANSCE	linac, booster, proton, cavity	280
	S.S. Kurennoy, L. Rybarcyk LANL, Los Alamos, New Mexico, USA V.A. Dolgashev SLAC, Menlo Park, California, USA
	Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. Using superconducting RF cavities with gradients ~15 MV/m after the existing linac would result in a long and expensive booster. We propose accomplishing the same with a much shorter cost-effective booster based on normal conducting high-gradient (~100 MV/m) RF accelerating structures. Such X-band high-gradient structures have been developed for electron acceleration and operate with typical RF pulse lengths below 1 us. They have never been used for protons because typical wavelengths and apertures are smaller than the proton bunch sizes. However, these limitations do not restrict proton radiography (pRad) applications. A train of very short proton bunches with the same total length and charge as the original long proton bunch will create the same single radiography frame, plus pRad limits contiguous trains of beam micro-pulses to below 60 ns to prevent blur in images. For a compact pRad booster at LANSCE, we explore feasibility of two-stage design: a short S-band section to capture and compress the 800-MeV proton beam followed by the main high-gradient X-band linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR065
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPLR067	First High Power Tests at the 325 MHz RF Test Stand at GSI	cavity, linac, coupling, rfq	287
	G. Schreiber, E. Plechov, J. Salvatore, B. Schlitt, A. Schnase, M. Vossberg GSI, Darmstadt, Germany
	A dedicated RF test stand for testing RF components and accelerating structures at 325 MHz has been put into operation at GSI. It allows testing the klystrons and circulators as well as the RFQ and the CH-acceleration cavities for the planned FAIR proton linac (p-Linac) and further cavity projects. The system integration has been completed and first high power tests with the CH prototype cavity were successfully performed. The operation parameters are 2 Hz repetition rate and 200 microseconds pulse length. Investigations on the critical path from wave guide to coaxial high power cavity coupler have been made. Performance measurements of the klystron, circulator and directional couplers with up to 2.8 MW on dummy load and the following conditioning process of the CH-prototype cavity with its coupled RF structures will be presented. Additionally the results of the conditioning of a ladder RFQ prototype are shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR067
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU2A01	State of the Art, Status and Future of RF Sources for Linacs	linac, operation, collider, status	353
	E. Jensen CERN, Geneva, Switzerland
	This talk tries an overview of recent developments in RF sources for linear accelerators of different scales and for various applications, spanning a frequency range from about 100 MHz to X-band, spanning duty factors from about 10^-3 to CW, and spanning power levels from a few kW up to hundreds of MW average. Exciting recent trends include new bunching concepts for klystrons promising a significant increase of efficiency and better power combiners paving the way to MW-class solid state power amplifiers.
	Slides TU2A01 [15.049 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TU2A01
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU2A02	Pulsed High Power Klystron Modulators for ESS Linac Based on the Stacked Multi-Level Topology	linac, operation, flattop, DTL	359
	C.A. Martins, G. Göransson, M. Kalafatic ESS, Lund, Sweden M. Collins Lund Technical University, Lund, Sweden
	ESS has launched an internal R&D project in view of designing, prototyping and validating a klystron modulator compatible with the requirements based on a novel topology named SML (Stacked Multi-Level). This topology is modular and based on the utilization of High Frequency (HF) transformers. The topology allows for the usage of industrial standard power electronic components at the primary stage at full extent which can easily be placed and wired in a conventional electrical cabinet. It requires only few special components like HF transformers, rectifiers and filters (i.e. passive components) to be placed in an oil tank. This arrangement allows scaling up in average and pulse power to the required levels while keeping the size, cost, efficiency and reliability of the different modules under good control. Besides the very good output pulse power quality, the AC grid power quality is also remarkably high with a line current harmonic distortion below 3%, a unitary power factor and an extremely reduced line voltage flicker below 0.3%. A reduced scale modulator prototype has been built and validated experimentally.
	Slides TU2A02 [8.596 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TU2A02
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TU2A04	High-Gradient RF Development and Applications	linac, collider, damping, beam-loading	368
	W. Wuensch CERN, Geneva, Switzerland
	Significant progress has been made by the CLIC collaboration to understand the phenomena which limit gradient in normal-conducting accelerating structures and to increase achievable gradient in excess of 100 MV/m. Scientific and technological highlights from the CLIC high-gradient program are presented along with on-going developments and future plans. The talk will also give an overview of the range of applications that potentially benefit from high-frequency and high-gradient accelerating technology.
	Slides TU2A04 [14.317 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TU2A04
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPLR017	Summary of the Test and Installation of 10 MW MBKs for the XFEL Project	cathode, ion, vacuum, linac	506
	V. Vogel (Fogel), L. Butkowski, A. Cherepenko, S. Choroba, J. Hartung, V.V. Kachaev, R. Wagner, S. Wiesenberg DESY, Hamburg, Germany
	For the European XFEL project, horizontal multi-beam klystrons (MBK) which produce RF power up to 10 MW, at an RF frequency of 1.3 GHz, 1.5 ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. All MBKs have been manufactured by two companies, 22 tubes from Thales Electron Devices and 7 tubes from Toshiba Electron Tubes & Devices. In this article we will give a summary of the tube testing, conditioning and installation in the underground linear accelerator tunnel.
	Poster TUPLR017 [1.975 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPLR044	Design and Operation of Pulsed Power Systems Built to ESS Specifications	high-voltage, operation, power-supply, electronics	558
	M.K. Kempkes, M.P.J. Gaudreau, M.G. Munderville, I. Roth Diversified Technologies, Inc., Bedford, Massachusetts, USA J. Domenge Sigma Phi Electronics, Wissembourg, France J.L. Lancelot Sigmaphi, Vannes, France
	Diversified Technologies, Inc. (DTI), in partnership with SigmaPhi Electronics (SPE) has built three long pulse solid-state klystron transmitters to meet spallation source requirements. Two of the three units are installed at CEA Saclay and the National Institute of Nuclear and Particle Physics (IN2P3), where they will be used as test stands for the European Spallation Source (ESS). The systems delivered to CEA and IN2P3 demonstrate that the ESS klystron modulator specifications (115 kV, 25 A per klystron, 3.5 ms, 14 Hz) have been achieved in a reliable, manufacturable, and cost-effective design. There are only minor modifications required to support transition of this design to the full ESS Accelerator, with up to 100 klystrons. The systems will accommodate the recently-determined increase in average power (~660 kW), can offer flicker-free operation, are equally-capable of driving Klystrons or MBIOTs, and are designed for an expected MTBCF of over ten years, based on operational experience with similar systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR044
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPLR045	Thyratron Replacement	operation, network, collider, medical-accelerators	561
	I. Roth, M.P.J. Gaudreau, M.K. Kempkes, M.G. Munderville Diversified Technologies, Inc., Bedford, Massachusetts, USA
	Funding: *Work supported by DOE under contract DE-SC0011292 Semiconductor thyristors have long been used as a replacement for thyratrons in low power or long pulse RF systems. To date, however, such thyristor assemblies have not demonstrated the reliability needed for installation in short pulse, high peak power RF stations used with many pulsed electron accelerators. The fast rising current in a thyristor tends to be carried in a small region, rather than across the whole device, and this localized current concentration can cause a short circuit failure. An alternate solid-state device, the insulated-gate bipolar transistor (IGBT), can readily operate at the speed needed for the accelerator, but commercial IGBTs cannot handle the voltage and current required. It is, however, possible to assemble these devices in arrays to reach the required performance levels without sacrificing their inherent speed. Diversified Technologies, Inc. (DTI) has patented and refined the technology required to build these arrays of series-parallel connected switches. DTI is currently developing an affordable, reliable, form-fit-function replacement for the klystron modulator thyratrons at SLAC capable of pulsing at 360 kV, 420 A, 6μs, and 120 Hz.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR045
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPLR047	Commissioning of XBox-3: A Very High Capacity X-band Test Stand	LLRF, controls, detector, FPGA	568
	N. Catalán Lasheras, C.F. Eymin, J. Giner Navarro, G. McMonagle, S.F. Rey, A. Solodko, I. Syratchev, B.J. Woolley, W. Wuensch CERN, Geneva, Switzerland T. Argyropoulos, D. Esperante Pereira IFIC, Valencia, Spain M. Volpi The University of Melbourne, Melbourne, Victoria, Australia
	The Compact Linear Collider (CLIC) beam-based acceleration baseline uses high-gradient travelling wave accelerating structures at a frequency of 12 GHz. In order to prove the performance of these structures at high peak power and short pulse width RF, two klystron-based test facilities have been put in operation in the last years. The third X-band testing facility at CERN (Xbox3) has recently been commissioned and has tripled the number of testing slots available. Xbox3 uses a novel way of combining relatively low peak power (6 MW) but high average power klystron units whose power is steered to feed four testing slots with RF to the required power with a repetition rate of up to 400 Hz. Besides the repetition rate, peak power, pulse length and pulse shape can be customized to fit the test requirements. This novel way of combining pulsed RF high power can eventually be used for many other applications where multiple test slots are required.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THOP05	Status and Operation of the ALBA Linac	linac, injection, operation, storage-ring	754
	R. Muñoz Horta, D. Lanaia, F. Pérez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	The pre-injector of the ALBA Light Source is a Linac that delivers electrons up to a maximum energy of 125 MeV. It consist in a pre-bunching, a bunching and two accelerating sections feed by two 35 MW klystrons. Since July 2014, ALBA is operating in top-up mode, and the Linac is delivering 110 MeV electrons in multibunch mode every 20 minutes. Recently, new injection modes have been implemented and successfully tested. For one side, injection to the ALBA Booster is now also available with only one of the two klystrons in operation, and the Linac delivering a 67 MeV beam. On the other hand, the Linac single bunch mode has been integrated to the top-up operation application. By means of an algorithm, single bunch mode operation provides any kind of filling pattern in the ALBA storage ring, with single bunch shots injected to those buckets with lowest current. The performance of the Linac beam operated in these different modes is reported.
	Slides THOP05 [0.604 MB]
	Poster THOP05 [4.967 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THOP05
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRC007	Development of 352.2 Mhz Power Coupler Window for R&D Purposes	cavity, simulation, electron, vacuum	779
	F. Geslin, M. Chabot, J. Lesrel, D. Reynet IPN, Orsay, France Ch.L. Lievin, S. Sierra TED, Velizy, France
	IPNO and Thales are conducting power couplers research and development. This paper present a new window design that fulfills European Spallation Source (ESS) requirements (400 kW RF peak power). The results of electromagnetic, thermal, thermo-mechanical, multipacting simulations and the consequences of the new ceramic window of power coupler will be reported. The multipacting simulations were performed with Musicc3D, software developed by IPNO. The new design overcome ceramic's weakness in tension and allows stronger constraints in the power coupler window.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPRC007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPLR067	Series Production of the RF Power Distribution for the European XFEL	cavity, coupling, cryogenics, status	1008
	S. Choroba, V.V. Katalev DESY, Hamburg, Germany E.M. Apostolov Technical University of Sofia, Sofia, Bulgaria
	The RF power distribution for the European XFEL allows for individual RF power for the 808 superconducting cavities of the European XFEL. It consists of a number of elements, not only waveguide components, but also girders, cables or cooling systems. The production of the RF distribution consists of several tasks. In order to deal with the schedule of the entire project a detailed planning, organization and monitoring of the series production of the RF power distribution was required. This paper describes the RF power distribution layout and the series production process.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR067
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MO1A02

Status of the European XFEL

linac, electron, undulator, operation

7

H. Weise
DESY, Hamburg, Germany

Funding: Work supported by the respective funding agencies of the contributing institutes; for details please see http:www.xfel.eu
The European XFEL under construction in Hamburg, Northern Germany, aims at producing X-rays in the range from 260 eV up to 24 keV out of three undulators that can be operated simultaneously with up to 27,000 pulses per second. The FEL is driven by a 17.5 GeV superconducting linac. Installation of this linac is now finished and commissioning is next. First lasing is expected for spring 2017. The paper summarizes the status of the project. First results of the injector commissioning are given.

Slides MO1A02 [28.909 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MO1A02

Export •

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

MOOP12

Klynac Design Simulations and Experimental Setup

cavity, linac, electron, simulation

68

K.E. Nichols, B.E. Carlsten, A. Malyzhenkov
LANL, Los Alamos, New Mexico, USA

Funding: The authors gratefully acknowledge the support of the US Department of Energy through the LANL/LDRD Program for this work.
We present results of a proof-of-principle demonstration of the first ever klynac, a compact 1 MeV linear accelerator with integrated klystron source using one electron beam. This device is bi-resonant, utilizing one resonant circuit for the klystron input and gain cavities, and one for the klystron output and linac cavities. The purpose of a klynac-type device is to provide a compact and inexpensive alternative for a conventional 1 to 6 MeV accelerator. A conventional accelerator requires a separate RF source and linac and all the associated hardware needed for that architecture. The klynac configuration eliminates many of the components to reduce the weight of the entire system by 60%. We have built an 8-cavity, 2.84-GHz RF structure for a 1-MeV bi-resonant klynac. A 50-kV, 10-A electron gun provides the single beam needed. Numerical modeling was used to optimize the design. The separation between the klynac ouput cavity and the first accelerator cavity was adjusted to optimize the bunch capture and a pin-hole aperture between the two cavities reduces the beam current in the linac section to about 0.1 A. Standard high-shunt impedance linac cavities designs are used. We have fabricated the first test structure. The structure will be tested with beam in early Summer 2016. Results will be presented at LINAC 2016.

Slides MOOP12 [1.136 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOOP12

Export •

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

MOPRC027

Surface Roughness Effect on the Performance of Nb3Sn Cavities

cavity, SRF, pulsed-power, niobium

129

R.D. Porter, D.L. Hall, M. Liepe, J.T. Maniscalco
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: DOE award DE-SC0008431
Surface roughness of current Niobium-3 Tin (Nb3Sn) superconducting radio-frequency (SRF) accelerator cavities can cause enhancement of the surface magnetic field. This enhancement can push the surface magnetic field beyond the critical field, which, if it occurs over a large enough area, can cause the cavity to quench. This paper presents simulations of the surface magnetic field enhancements in SRF cavities caused by the surface roughness of current Cornell Nb3Sn cavities, which have achieved record efficiency. Simple, smooth cavity geometry is defined and surface magnetic fields calculated using SLANS2. The cavity geometry is modified with a small rough region for which the geometry is determined from AFM scans of a Nb3Sn coated sample and the surface fields are calculated again. The calculated surface fields of the smooth and rough cavities are compared to determine the extent of the field enhancement, the area over which the enhancement is significant, and which surface features cause large field enhancement. We find that 1% of the surface analyzed has fields enhance by more than 45%. On average the Q-factor is increased by (3.8 ± 1.0) \%.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC027

Export •

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

MOPLR018

Upgrade of the Klystron Modulator of the L-Band Electron Linac at Osaka University for Higher Stability

resonance, impedance, linac, high-voltage

178

K. Furukawa, G. Isoyama
ISIR, Osaka, Japan
R. Kato
KEK, Ibaraki, Japan
K. Kawase
HSRC, Higashi-Hiroshima, Japan
A. Tokuchi
Pulsed Power Japan Laboratory Ltd., Kusatsu-shi Shiga, Japan

The klystron modulator for the L-band linac is upgraded for higher stability. The two-step charging system for the pulse forming network (PFN) is upgraded by adding a high impedance resonant charging line in parallel with the main line. The charging step of the PFN voltage is reduced considerably near the setting value by switching the main resonance line off so that the charging current flows only through the high impedance line. The second model of the solid-state switch is developed using 60 static-induction thyristors, ten of which are connected in series with six such series connected in parallel to meet maximum specifications of 25 kV and 6 kA. The air-cooling capacity is reinforced so that repetition rate is increased from 10 pps for the first model to 60 pps. The fluctuation and accuracy of the klystron voltage are measured to be 7.8×10^-6 or 7.8 ppm for the upgraded klystron modulator using a differential amplifier with much higher sensitivity than one used in the previous measurement.

Poster MOPLR018 [0.840 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR018

Export •

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

MOPLR065

High-Gradient X-band Structures for Proton Energy Booster at LANSCE

linac, booster, proton, cavity

280

S.S. Kurennoy, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA
V.A. Dolgashev
SLAC, Menlo Park, California, USA

Increasing energy of proton beam at LANSCE from 800 MeV to 3 GeV improves radiography resolution ~10 times. Using superconducting RF cavities with gradients ~15 MV/m after the existing linac would result in a long and expensive booster. We propose accomplishing the same with a much shorter cost-effective booster based on normal conducting high-gradient (~100 MV/m) RF accelerating structures. Such X-band high-gradient structures have been developed for electron acceleration and operate with typical RF pulse lengths below 1 us. They have never been used for protons because typical wavelengths and apertures are smaller than the proton bunch sizes. However, these limitations do not restrict proton radiography (pRad) applications. A train of very short proton bunches with the same total length and charge as the original long proton bunch will create the same single radiography frame, plus pRad limits contiguous trains of beam micro-pulses to below 60 ns to prevent blur in images. For a compact pRad booster at LANSCE, we explore feasibility of two-stage design: a short S-band section to capture and compress the 800-MeV proton beam followed by the main high-gradient X-band linac.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR065

Export •

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

MOPLR067

First High Power Tests at the 325 MHz RF Test Stand at GSI

cavity, linac, coupling, rfq

287

G. Schreiber, E. Plechov, J. Salvatore, B. Schlitt, A. Schnase, M. Vossberg
GSI, Darmstadt, Germany

A dedicated RF test stand for testing RF components and accelerating structures at 325 MHz has been put into operation at GSI. It allows testing the klystrons and circulators as well as the RFQ and the CH-acceleration cavities for the planned FAIR proton linac (p-Linac) and further cavity projects. The system integration has been completed and first high power tests with the CH prototype cavity were successfully performed. The operation parameters are 2 Hz repetition rate and 200 microseconds pulse length. Investigations on the critical path from wave guide to coaxial high power cavity coupler have been made. Performance measurements of the klystron, circulator and directional couplers with up to 2.8 MW on dummy load and the following conditioning process of the CH-prototype cavity with its coupled RF structures will be presented. Additionally the results of the conditioning of a ladder RFQ prototype are shown.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR067

Export •

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

TU2A01

State of the Art, Status and Future of RF Sources for Linacs

linac, operation, collider, status

353

E. Jensen
CERN, Geneva, Switzerland

This talk tries an overview of recent developments in RF sources for linear accelerators of different scales and for various applications, spanning a frequency range from about 100 MHz to X-band, spanning duty factors from about 10^-3 to CW, and spanning power levels from a few kW up to hundreds of MW average. Exciting recent trends include new bunching concepts for klystrons promising a significant increase of efficiency and better power combiners paving the way to MW-class solid state power amplifiers.

Slides TU2A01 [15.049 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TU2A01

Export •

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

TU2A02

Pulsed High Power Klystron Modulators for ESS Linac Based on the Stacked Multi-Level Topology

linac, operation, flattop, DTL

359

C.A. Martins, G. Göransson, M. Kalafatic
ESS, Lund, Sweden
M. Collins
Lund Technical University, Lund, Sweden

ESS has launched an internal R&D project in view of designing, prototyping and validating a klystron modulator compatible with the requirements based on a novel topology named SML (Stacked Multi-Level). This topology is modular and based on the utilization of High Frequency (HF) transformers. The topology allows for the usage of industrial standard power electronic components at the primary stage at full extent which can easily be placed and wired in a conventional electrical cabinet. It requires only few special components like HF transformers, rectifiers and filters (i.e. passive components) to be placed in an oil tank. This arrangement allows scaling up in average and pulse power to the required levels while keeping the size, cost, efficiency and reliability of the different modules under good control. Besides the very good output pulse power quality, the AC grid power quality is also remarkably high with a line current harmonic distortion below 3%, a unitary power factor and an extremely reduced line voltage flicker below 0.3%. A reduced scale modulator prototype has been built and validated experimentally.

Slides TU2A02 [8.596 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TU2A02

Export •

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

TU2A04

High-Gradient RF Development and Applications

linac, collider, damping, beam-loading

368

W. Wuensch
CERN, Geneva, Switzerland

Significant progress has been made by the CLIC collaboration to understand the phenomena which limit gradient in normal-conducting accelerating structures and to increase achievable gradient in excess of 100 MV/m. Scientific and technological highlights from the CLIC high-gradient program are presented along with on-going developments and future plans. The talk will also give an overview of the range of applications that potentially benefit from high-frequency and high-gradient accelerating technology.

Slides TU2A04 [14.317 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TU2A04

Export •

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

TUPLR017

Summary of the Test and Installation of 10 MW MBKs for the XFEL Project

cathode, ion, vacuum, linac

506

V. Vogel (Fogel), L. Butkowski, A. Cherepenko, S. Choroba, J. Hartung, V.V. Kachaev, R. Wagner, S. Wiesenberg
DESY, Hamburg, Germany

For the European XFEL project, horizontal multi-beam klystrons (MBK) which produce RF power up to 10 MW, at an RF frequency of 1.3 GHz, 1.5 ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. All MBKs have been manufactured by two companies, 22 tubes from Thales Electron Devices and 7 tubes from Toshiba Electron Tubes & Devices. In this article we will give a summary of the tube testing, conditioning and installation in the underground linear accelerator tunnel.

Poster TUPLR017 [1.975 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR017

Export •

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

TUPLR044

Design and Operation of Pulsed Power Systems Built to ESS Specifications

high-voltage, operation, power-supply, electronics

558

M.K. Kempkes, M.P.J. Gaudreau, M.G. Munderville, I. Roth
Diversified Technologies, Inc., Bedford, Massachusetts, USA
J. Domenge
Sigma Phi Electronics, Wissembourg, France
J.L. Lancelot
Sigmaphi, Vannes, France

Diversified Technologies, Inc. (DTI), in partnership with SigmaPhi Electronics (SPE) has built three long pulse solid-state klystron transmitters to meet spallation source requirements. Two of the three units are installed at CEA Saclay and the National Institute of Nuclear and Particle Physics (IN2P3), where they will be used as test stands for the European Spallation Source (ESS). The systems delivered to CEA and IN2P3 demonstrate that the ESS klystron modulator specifications (115 kV, 25 A per klystron, 3.5 ms, 14 Hz) have been achieved in a reliable, manufacturable, and cost-effective design. There are only minor modifications required to support transition of this design to the full ESS Accelerator, with up to 100 klystrons. The systems will accommodate the recently-determined increase in average power (~660 kW), can offer flicker-free operation, are equally-capable of driving Klystrons or MBIOTs, and are designed for an expected MTBCF of over ten years, based on operational experience with similar systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR044

Export •

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

TUPLR045

Thyratron Replacement

operation, network, collider, medical-accelerators

561

I. Roth, M.P.J. Gaudreau, M.K. Kempkes, M.G. Munderville
Diversified Technologies, Inc., Bedford, Massachusetts, USA

Funding: *Work supported by DOE under contract DE-SC0011292
Semiconductor thyristors have long been used as a replacement for thyratrons in low power or long pulse RF systems. To date, however, such thyristor assemblies have not demonstrated the reliability needed for installation in short pulse, high peak power RF stations used with many pulsed electron accelerators. The fast rising current in a thyristor tends to be carried in a small region, rather than across the whole device, and this localized current concentration can cause a short circuit failure. An alternate solid-state device, the insulated-gate bipolar transistor (IGBT), can readily operate at the speed needed for the accelerator, but commercial IGBTs cannot handle the voltage and current required. It is, however, possible to assemble these devices in arrays to reach the required performance levels without sacrificing their inherent speed. Diversified Technologies, Inc. (DTI) has patented and refined the technology required to build these arrays of series-parallel connected switches. DTI is currently developing an affordable, reliable, form-fit-function replacement for the klystron modulator thyratrons at SLAC capable of pulsing at 360 kV, 420 A, 6μs, and 120 Hz.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR045

Export •

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

TUPLR047

Commissioning of XBox-3: A Very High Capacity X-band Test Stand

LLRF, controls, detector, FPGA

568

N. Catalán Lasheras, C.F. Eymin, J. Giner Navarro, G. McMonagle, S.F. Rey, A. Solodko, I. Syratchev, B.J. Woolley, W. Wuensch
CERN, Geneva, Switzerland
T. Argyropoulos, D. Esperante Pereira
IFIC, Valencia, Spain
M. Volpi
The University of Melbourne, Melbourne, Victoria, Australia

The Compact Linear Collider (CLIC) beam-based acceleration baseline uses high-gradient travelling wave accelerating structures at a frequency of 12 GHz. In order to prove the performance of these structures at high peak power and short pulse width RF, two klystron-based test facilities have been put in operation in the last years. The third X-band testing facility at CERN (Xbox3) has recently been commissioned and has tripled the number of testing slots available. Xbox3 uses a novel way of combining relatively low peak power (6 MW) but high average power klystron units whose power is steered to feed four testing slots with RF to the required power with a repetition rate of up to 400 Hz. Besides the repetition rate, peak power, pulse length and pulse shape can be customized to fit the test requirements. This novel way of combining pulsed RF high power can eventually be used for many other applications where multiple test slots are required.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR047

Export •

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

THOP05

Status and Operation of the ALBA Linac

linac, injection, operation, storage-ring

754

R. Muñoz Horta, D. Lanaia, F. Pérez
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain

The pre-injector of the ALBA Light Source is a Linac that delivers electrons up to a maximum energy of 125 MeV. It consist in a pre-bunching, a bunching and two accelerating sections feed by two 35 MW klystrons. Since July 2014, ALBA is operating in top-up mode, and the Linac is delivering 110 MeV electrons in multibunch mode every 20 minutes. Recently, new injection modes have been implemented and successfully tested. For one side, injection to the ALBA Booster is now also available with only one of the two klystrons in operation, and the Linac delivering a 67 MeV beam. On the other hand, the Linac single bunch mode has been integrated to the top-up operation application. By means of an algorithm, single bunch mode operation provides any kind of filling pattern in the ALBA storage ring, with single bunch shots injected to those buckets with lowest current. The performance of the Linac beam operated in these different modes is reported.

Slides THOP05 [0.604 MB]

Poster THOP05 [4.967 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THOP05

Export •

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

THPRC007

Development of 352.2 Mhz Power Coupler Window for R&D Purposes

cavity, simulation, electron, vacuum

779

F. Geslin, M. Chabot, J. Lesrel, D. Reynet
IPN, Orsay, France
Ch.L. Lievin, S. Sierra
TED, Velizy, France

IPNO and Thales are conducting power couplers research and development. This paper present a new window design that fulfills European Spallation Source (ESS) requirements (400 kW RF peak power). The results of electromagnetic, thermal, thermo-mechanical, multipacting simulations and the consequences of the new ceramic window of power coupler will be reported. The multipacting simulations were performed with Musicc3D, software developed by IPNO. The new design overcome ceramic's weakness in tension and allows stronger constraints in the power coupler window.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPRC007

Export •

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

THPLR067

Series Production of the RF Power Distribution for the European XFEL

cavity, coupling, cryogenics, status

1008

S. Choroba, V.V. Katalev
DESY, Hamburg, Germany
E.M. Apostolov
Technical University of Sofia, Sofia, Bulgaria

The RF power distribution for the European XFEL allows for individual RF power for the 808 superconducting cavities of the European XFEL. It consists of a number of elements, not only waveguide components, but also girders, cables or cooling systems. The production of the RF distribution consists of several tasks. In order to deal with the schedule of the entire project a detailed planning, organization and monitoring of the series production of the RF power distribution was required. This paper describes the RF power distribution layout and the series production process.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR067

Export •

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