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PULse POwer for Kicker Systems (PULPOKS) workshop 2018
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Europe/Zurich
6/2-004 (CERN)
Description
Overview
In March 2018 a Pulse Power for Kicker Systems workshop is to be held at CERN, and will address several topics associated with pulse power for kickers, as well as providing a forum for discussion between experts in this specialised domain.
The Pulse Power for Kicker Systems workshop 2018 is supported by ARIES (the successor of EuCARD2) and FCC.
Participants
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08:30
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08:50
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08:40
Overview of the workshop 10mSpeaker: Mike Barnes (CERN)
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08:50
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10:00
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08:50
Volunteers: up to 3-4 min (1 slide/minute) each to introduce themselves & their labs, and interesting projects 1h 10m
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Introduction to Fast Pulsed Magnets at BESSY II and MLS synchrotron light sources @ HZB 4mSpeaker: Olaf Dressler (Helmholtz-Zentrum Berlin)
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Elettra Introduction 4mSpeaker: Piergiorgio Tosolini (Elettra Sincrotrone Trieste)
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ISIS Introduction 4mSpeaker: Jonny Ranner (STFC)
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FERMILAB Introduction 4mSpeaker: Christopher Jensen
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Diamond Light Source Introduction 4mSpeaker: Colin Abraham (Diamond Light Source)
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Russian Academy of Sciences 4mSpeaker: Anton Gusev (Institute of Electrophysics)
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CERN Introduction 4mSpeaker: Mike Barnes (CERN)
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ALBA Introduction 4mSpeaker: Montse Pont (CELLS-ALBA)
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DESY Introduction 4m
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SOLEIL Introduction 4mSpeaker: Patrick Alexandre (Synchrotron SOLEIL)
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PSI Introduction 4mSpeaker: Christopher Gough (Paul Scherrer Institut)
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08:50
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10:00
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10:30
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10:30
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12:00
Convener: Laurent Sylvain Ducimetiere (CERN)
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10:30
Electrostatic chopper for Super MuSR muon beamline 30m
"Electrostatic chopper for Super MuSR muon beamline"
The upgrade to the MuSR muon beamline at ISIS will include an electrostatic chopper, designed to improve the timing resolution of muon experiments. The chopper is required to switch from +80 kV (ยฑ40 kV on each plate) to 80 kV in 10 ns, sweeping the beam across an aperture at a precise time. A feasibility study has been undertaken and a design based on thyratrons is being developed. This talk will present our conceptual design, some of the problems we expect to face and potential solutions. Beneficial discussion around this topic will include experiences of designing and operating similar systems at other facilities.
Speaker: Jonny Ranner (STFC) -
11:00
Pulsing Kickers by Thyratrons at Elettra (1990...2018)performance during operations of ELLETRA 30mSpeaker: Piergiorgio Tosolini (Elettra Sincrotrone Trieste)
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11:30
Statistical Life-Time Analysis of Thyratrons in CERN Kicker Systems 30m
"Statistical Life-Time Analysis of Thyratrons in CERN Kicker Systems"
CERN has a long experience working with thyratrons in kicker systems.
A large variety of thyratrons from E2V are in use.
After a brief reminder about thyratron devices, the talk will give a summary of the tubes used in CERN kicker systems and their performance in terms of lifetime and reliability.Speaker: Luc Sermeus (CERN)
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10:30
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12:00
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13:30
Lunch 1h 30m Restaurant 2
Restaurant 2
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13:30
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14:30
Convener: Jonny Ranner (STFC)
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13:30
Experience with HV cables and connectors 30m
"Cables"
High voltage cables and wires of many types are needed in any high voltage system. There is sometimes a choice in construction type for pulse applications, especially with fast rise or fall time. Wires and cables used for DC high voltage do not typically perform well when long lifetimes, > 10^8 pulses, are required. An overview cable construction types, issues with pulse shape, and issues with high voltage will be presented. Two examples will be presented, one using a commercial DC connector and cable for several ยตs rise time pulses at 30 kV and one of a semi custom cable connector with a semi custom cable with rise time of 15 ns for kicker use at 60 kV. Experience in the USA with procurement of pulse forming cable will also be presented.
Speaker: Christopher Jensen -
14:00
Overview of HV Cables and Connectors, Cable Procurement and Future Work 30mSpeaker: Thomas Kramer (CERN)
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13:30
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14:30
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15:00
Convener: Piergiorgio Tosolini (Elettra Sincrotrone Trieste)
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14:30
Light Triggering of Thyristors 30m
โLight Triggering of Thyristorsโ
Appropriate illumination of thyristor structure with a laser beam can lead to commutation characteristics improvement. One electron-hole pair is photo-generated within a few femtoseconds, silicon, an indirect band gap photoconductive material, exhibits large absorption depths for 1 ฮผm photons wavelength. The controlling source photon energy needs to be greater than the photoconductor bandgap energy in order to โpumpโ the electrons into conduction band. Small closure time, improved maximal di/dt ratings and controlling source electrical insulation are the main advantages of this method.
The presentation will discuss the basics of thyristor light activation, motivations for development and tests demonstrations done on market available SCR devices (Silicon Controlled Rectifier).Speaker: Janusz Pawel Rodziewicz (CERN)
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14:30
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15:00
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15:30
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15:30
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17:30
Session 4 : Pulsed measurements and online monitoring and analysis 6/2-004Convener: Etienne Carlier (CERN)
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15:30
Internal Post-Operation Check (IPOC) System for Kicker Magnet Current Waveform Surveillance 30mSpeaker: Nicolas Magnin (CERN)
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16:00
Pulsed measurements and online monitoring and analysis 30m
"Measurements and diagnostic of kickers pulses through ADC systems"
ALBA is a 3rd generation synchrotron light source operating for users since 2012. Since 2014 the storage ring is operated in top-up mode with injections every 20min. The injection into the storage ring is performed using a septum and a closed bump created by 4 kickers. The kickers must have identical, shape, amplitude and be perfectly synchronized to avoid perturbations on the stored beam that will affect the brightness of the photon beam. To measure the kickers pulses and to able to control the differences online we have recently installed a system based on analog-to-digital converters cards (ADCs) with a large sampling rate and good resolution. The presentation will summarize the installation and programming of the ADCs as well as its integration into the accelerator control system. Measurements will be presented that show the resolution achieved as well as the correlation of the acquired data with other machine parameters.
Speaker: Nuria Ayala (ALBA-CELLS synchrotron) -
16:30
Pulse Current Monitoring for Fast Pulsed Magnets at BESSY II and MLS Light Sources 30m
โPulse Current Monitoring for Fast Pulsed Magnets at BESSY II and MLS light sourcesโ
The BESSY II and MLS storage rings are 3rd generation light sources. While the first one is usually operated in the top-up-injection mode, where injection efficiencies above 90% are required, the second one requires every 6 hours a dedicated injection procedure to refill for user operations.
To support the commissioning and operation of the both storage rings, modular pulse current monitoring systems have been developed. These are based on National Instruments PXI technology, and programmed with LabVIEW. The so retrieved data is processed, and then transferred by the help of an in-house made โCA-Labโ client software into the EPICS based machine control system. The systems are retained in continuous 24/7 operation since they were introduced about 5 years ago.
The measurement of pulse currents on all pulsed deflection magnets is essential for the stable and uninterrupted operation of the accelerators. Strategies to unveil unwanted operational conditions of the pulsed elements, e.g. instabilities or misfiring, are also discussed.Speaker: Olaf Dressler (Helmholtz-Zentrum Berlin) -
17:00
High stability resonant kicker system for Swiss Free Electron Laser (SwissFEL) at Paul Scherrer Institute 30m
"High stability resonant kicker system for Swiss Free Electron Laser (SwissFEL) at Paul Scherrer Institute"
To increase SwissFEL efficiency, a double bunch operation is planned in order to serve simultaneously two experimental stations at the full linac repetition rate. The kicker system has to separate two electron bunches that are 28 ns apart and send them to two separate beamlines. Since the stability of the electron beam is crucial for the performance of the free electron laser a novel concept of high stability resonant kicker based bunches separation was adopted. Sub-part-per-million pulse-to-pulse kickersโ amplitude stability was measured using balancing method.
Speaker: Dr Martin Paraliev (Paul Scherrer Institute)
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15:30
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19:30
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22:00
Dinner 2h 30m Restaurant "Le Smash"
Restaurant "Le Smash"
Chemin de la Berne 5, 1217 Meyrin, Suisse
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08:30
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08:50
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11:30
Convener: Mike Barnes (CERN)
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08:30
Superfast Thyristor-Based Switches Operating in Impact-Ionization Wave Mode 25m
"Thyristor-Based Switches Operating in Impact-Ionization Wave Mode for Pulsed Power Applications"
Thyristors of tablet design with diameters of silicon wafers of 40 to 56 mm and an operating voltage of 2 to
2.4 kV DC were triggered by an external overvoltage pulse applied across the thyristor main electrodes. In
experiments a voltage rise rate across the thyristor was changed from 1 to 6 kV/ns. Under such conditions
the thyristor closing process occurred due to initiation and propagation of a fast ionization front across the
semiconductor structure, which fills the structure with dense electron-hole plasma within 200 to 400 ps. The
thyristor based switches contained 2 to 9 series connected thyristors and operated in this triggering mode in
different discharge circuits. Operating voltage was 5 to 20 kV, capacitance of discharge capacitors was 2 ฮผF
to 1.2 mF, and stored energy was 0.4 to 15 kJ.The experimental results obtained covered the following range
of discharge parameters: discharge current amplitude of 10 to 200 kA, current rise rate of 15 to 130 kA/ฮผs,
current rise time (0.1-0.9 level) of 0.4 to 5 ฮผs, pulse duration (FWHM) of 1 to 20 ฮผs, and switching efficiency
of 0.85 to 0.97. Effect of the voltage rise rate at the triggering stage as well as temperature of the silicon
wafer on the thyristors main switching characteristics will be shown. Results of the thyristors testing in pulse
repetition mode will be given. The experimental circuitry, tested switches design, and results obtained will be
discussed.Speaker: Anton Gusev (Institute of Electrophysics) -
08:55
Experience in rad hard tests of LBDS 25m
"Experience in rad hard tests of LBDS"
LHC beam dumping system (LBDS) employs altogether 800 HV GTO like thyristors and 480 HV triggering IGBTs. It delivers up to 1 million amperes to 30 extraction and 20 dilution magnets in order to safely deposit both 7 TeV beams on their respective dump blocks. Because of crucial importance of reliable operation of LBDS for LHC safety, various failure mode were investigated, one of them being Single Event Burnout (SEB) of HV semiconductors used. In house developed method for non-destructive measurement of SEB cross-section was used for measurement of this parameter for all HV semiconductors used and mitigations were applied where necessary. Based on these measurements the probability of SEB related failure rate of LBDS was evaluated.
Speaker: Viliam Senaj (CERN) -
09:20
Experience of Solid-state modulators for HV kickers and septa at SOLEIL 25m
"Experience of Solid-state modulators for HV kickers and septa at SOLEIL"
The pulsed systems for beam injection & extraction at SOLEIL only use solid-state switches in the pulsers. During the technical design of the machine, this had been a strong requirement in order to get excellent availability and reliability of the equipment themselves but also to obtain excellent Top-Up performance, particularly for the 4 storage ring kicker systems. The presentation will go over the design and performance we have obtained for over 10 years of operation at SOLEIL.
Speaker: Patrick Alexandre (Synchrotron SOLEIL) -
09:45
Marx generators for kickers 25mSpeaker: Luis Manuel Dos Santos Redondo (ISEL Instituto Superior de Engenharia (PT))
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10:10
Coffee break 30m
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10:40
Inductive Adders for CLIC DR Kickers and FCC Injection Kicker Systems 25mSpeakers: David Woog (CERN), Janne Holma (CELLS (ES))
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11:05
The Ultra-Fast Kicker Strip-line with a FID Pulse Generator + Prototype for the New EBS Kicker Magnet, using Solid-state Switches 25mSpeaker: Marc Dubrulle (ESRF)
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08:30
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11:30
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13:45
Convener: Martin Paraliev (Paul Scherrer Institute)
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11:30
CST simulations of speed limitations of inductive adder topology 25m 6/2-004
"CST simulations of speed limitations of inductive adder topology"
C.Gough, S.DordevicUsing time domain simulations, the progression of E and H fields inside an IVA (Inductive Voltage Adder) can
be visualised in 3D. The pulse generator sources are idealised voltage sources with minimum series impedance.
A rise time of 4ns is typically used. Faster rise times lead to multiple resonant modes in the structure; these
modes are sometimes asymmetric, and these modes make interpretation difficult. Many lengths and geometries of
an IVA are tried to find an optimum for speed. For practical application, the design of fast switches with
minimial series impedance is dominating the problem, not the IVA itself.Speakers: Christopher Gough (Paul Scherrer Institut), Martin Paraliev (Paul Scherrer Institute), Saldana Dordevic (Paul Scherrer Institut) -
11:55
Lunch 1h 25m Restaurant 2
Restaurant 2
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13:20
This presentation briefly reviews using PSpice and Opera-2d for modelling frequency dependent resistance and inductance, such as skin effect and proximity effect: the PSpice equivalent circuit can be used in both frequency- and time-domain PSpice simulations. In addition the presentation briefly reviews modelling of a multi-gap thyratron for time-domain simulation of turn-on: this allows the modelling of pre-pulse displacement current.
Speakers: Laurent Sylvain Ducimetiere (CERN), Luc Sermeus (CERN), Mike Barnes (CERN)
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11:30
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13:45
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15:55
Convener: Montse Pont (CELLS-ALBA)
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13:45
NLK designed by Soleil and MAX-IV and recently installed at MAX-IV 25m
"The Multipole Injection Kicker"
Transparent Top-Up injection in the next generation of storage rings (DLSRs), such as MAX-IV 3 GeV ring, is very challenging as dynamic apertures & available room shrink very quickly in the design of the lattices! One solution is to use a Non Linear Kicker to kick in the injected beam while not affecting the stored beam, using the non-linear behavior of the magnetic field. MAX-IV and SOLEIL have been collaborating for more than six years on the design, manufacture and installation of such pulsed magnet system in their storage rings. The presentation will go over some main challenges of the project from the initial specifications to the first measurements with beam.
Speaker: Patrick Alexandre (Synchrotron SOLEIL) -
14:10
FAIR SIS-100 Kicker Systems 25mSpeaker: Sebastian Heberer (GSI)
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14:35
Magnetic materials 25m
"Magnetic Materials"
Magnetic materials are used in many different pulse applications, from small pulse transformers to kicker magnets. The use of these materials in pulse application has some unique considerations. A short review of basic magnetic material concepts, some material fabrication background, and some pulse measurement techniques will be presented. Two examples with emphasis on soft ferrite materials will be presented, one of a fast ferrite kicker magnet and one of a saturating ferrite for kicker pulse sharpening. Recent experience in the USA with procurement of large ferrite shapes will also be presented.
Speaker: Christopher Jensen -
15:00
Coffee break 30m
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15:30
Experience and procurement of ferrites and alternative materials 25m
Kicker magnets require dedicated magnetic material to achieve good field uniformity with fast rise and fall time. Historically CERN uses 8C11/CMD5005, NiZn, ferrite to accomplish this and recent procurement has shown increased difficulties in obtaining the required large cores, mainly due to the difficulty in machining to our strict tolerances. Nevertheless, other types of ferrite, with higher Curie temperature are being considered. In addition, it is our intention to experiment in a near future with alternative materials and at the present two options are being considered.
This presentation will present the currently used ferrite options, highlighting the difficulties in supply, and will discuss alternative options including strip-wound cores and Nano-crystalline materials.Speakers: Laurent Sylvain Ducimetiere (CERN), Luis Miguel Coralejo Feliciano (CERN), Mike Barnes (CERN), Viliam Senaj (CERN), Wim Weterings (CERN)
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13:45
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15:55
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16:45
Convener: Marc Dubrulle (ESRF)
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15:55
Metallization/coating of kicker magnets 25mSpeakers: Laurent Sylvain Ducimetiere (CERN), Mike Barnes (CERN), Tobias Stadlbauer (CERN)
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16:20
Shielding of MKI/MKE kicker magnets 25mSpeakers: Mike Barnes (CERN), Vasileios Vlachodimitropoulos (CERN)
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15:55
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16:45
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17:30
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16:45
Feedback: what worked well?, can be done better? 45m
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16:45
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08:30
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11:30
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08:45
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09:00
Meet the guides at Restaurant 2 15m Restaurant 2
Restaurant 2
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09:00
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11:30
Visit (AD & LEIR) 2h 30m
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08:45
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09:00
