ICFA mini-WORKSHOP ON IMPEDANCES AND BEAM INSTABILITIES IN PARTICLE ACCELERATORS

18 Sept 2017, 18:00 → 22 Sept 2017, 20:40 Europe/Rome

San Vittorino Hall (Benevento)

We are pleased to announce  the International Workshop on  Impedances and Beam Instabilities in Particle Accelerators, to be held in Benevento (Italy) from 18 to 22 September, 2017.  
 
The workshop is intended to continue the tradition of dedicated conferences on beam coupling impedances in particle accelerators, initiated with the 2014 ICFA mini-Workshop on “Electromagnetic Wake Fields and Impedances in Particle Accelerators” held in Erice (organized by Vittorio Vaccaro, Iaia Masullo and Elias Métral). The aim of the upcoming event is to provide an up-to-date review of the subject, while widening its scope to include recent advances on beam instabilities.

The workshop will be hosted by the University of Sannio at Benevento, under the auspices of INFN, SIF and CERN - and with the sponsorship of ARIES, LIU, Collimation and HL-LHC.
Benevento is a world heritage city in Southern Italy, where you will find  remarkable monuments and fine pieces of arts, in a unique cultural and natural environment. Benevento is easily reached (two hours from Rome by train, one hour from Naples airport, by bus). The conference venue is in the heart of the city center, in a short walking distance from all attractions, hotels and restaurants.

We look very much forward to welcoming you in Benevento, to contribute to a stimulating and memorable workshop!

The workshop chairs:
Maria Rosaria Masullo (Masullo@na.infn.it)
Stefania Petracca (Petracca@sa.infn.it)
Giovanni Rumolo (Giovanni.Rumolo@CERN.ch) 

For any questions please contact:           imped2017@unisannio.it


NEW

The chairpersons are glad to announce that the proceedings of this ICFA Mini-Workshop on Impedances and Beam Instabilities have been published as CERN Yellow Report (CERN-2018-003-CP) and are available at this link

      

Local Organizing Committee (LOC)

• Stefania Petracca (University of Sannio)
• Maria Rosaria Masullo (INFN Naples)

Poster poster_final-1.pdf

QR code qr.png

Website Website

Monday, 18 September

18:00 → 22:00 Registration and Welcome Cocktail

Participant must register at the registration desk upon arrival.

18:00 → 22:00 Visit of the Hortus Conclusus

Tuesday, 19 September

09:00 → 12:30 Session 1- Introductory talks (Chair: Giovanni Rumolo)

Convener: Dr Giovanni Rumolo (CERN)

09:00 Welcome and general introduction

Speaker: Stefania Petracca (SA)

Slides petracca.pptx

09:30 Impedance theory and modeling

Speaker: Dr Elias Metral (CERN)

Slides ImpedanceTheoryAndModeling_EM_2017.pdf ImpedanceTheoryAndModeling_EM_2017.pptx

10:00 Impedance measurement techniques

Speaker: Dr Uwe Niedermayer (TU-Darmstadt)

Slides Niedermayer.ppt

10:30 Coffee break

11:00 Electron cloud effects

Speaker: Mr Giovanni Iadarola (CERN - Università di Napoli Federico II)

Slides 014_ecloud_general.pptx

11:30 Instability theory and modeling

Speaker: Prof. Oliver Boine-Frankenheim (Technische Universität Darmstadt)

Slides BoineFrank_Benevento_2017.pptx

12:00 Instability observations and cures

Speaker: Dr Elena Shaposhnikova (CERN)

Slides benevento_ES.pptx

12:30 → 14:30 LUNCH Break

14:30 → 18:10 Session 2 - Impedance theory and modeling (Chair: Ursula Van Rienen. Scientific secretary: Mario Beck)

14:30 Wakefields/impedances for a bunch moving between two corrugated plates

Speaker: Karl Bane (SLAC)

Slides kbane_dechirper.pdf

14:50 Calculation of wakefields for plasma-wakefield accelerators

Speaker: Dr Gennady Stupakov (SLAC)

Slides Stupakov._Plasma_wake.pdf

15:10 Advanced method of wakefield calculations (numerical methods, parallel computing)

Speaker: Dr Erion Gjonaj (TU-Darmstadt)

Slides 2-1-3_EG_Benevento_2017.pptx

15:30 Analytical impedance models for very short bunches

Speaker: Igor Zagorodnov (DESY)

Slides ICFA_talk_Zagorodnov.pdf ICFA_talk_Zagorodnov.pptx

15:50 Coffee break

16:20 Multi-physics simulations of impedance effects in accelerators

Speaker: Dr Carlo Zannini (ADAM)

Slides multiphysics_benevento_CZ.pptx

16:40 Impedance Issues in the Design, Measurements, and Beam Commissioning of a Narrow Gap Stripline Kicker For On-Axis Injection

Speaker: Dr Stefano De Santis (LBNL)

Slides SDSbenevento.pptx

17:00 Eigenmode Computations for Chains of Cavities

Speaker: Thomas Flisgen (Helmholtz Zentrum Berlin)

Slides 2-2-3_Flisgen_ICFA_Workshop.ppt

17:20 The concept of coupling impedance in the self-consistent plasma wake field excitation

Speaker: Prof. Renato Fedele (Scuola Politecnica e delle Scienze di Base, Dipartimento di Fisica, Università di Napoli Federico II and INFN Sezione di Napoli, Napoli, Italy)

Slides 2-2-4_Renato_Talk_Benevento-19-09-2017.pdf

17:40 "The Birth and the Childhood of the Coupling Impedance and the Stability Maps" Special seminar to celebrate the 50 years of the beam coupling impedance concept

Speaker: Vittorio Giorgio Vaccaro (NA)

Slides 2-2-5_Beneventum1.pptx

20:00 → 22:00 Welcome Dinner

Wednesday, 20 September

09:00 → 12:30 Session 3: Impedance modeling, measurements and control (Chair: Maria Rosaria Masullo. Scientific secretary: Andrea Passarelli)

Convener: Maria Rosaria Masullo (NA)

09:00 Challenges and pitfalls for impedance measurements in the lab

Speaker: Andrea Mostacci (ROMA1)

Slides Mostacci_impedance_meas_pitfalls_final.pptx

09:20 2D and 3D collimator impedance modelling and experimental measurements

Speaker: Dr Nicolo Biancacci (CERN)

Slides ICFA_Impedance_20092017_NB.pptx

09:40 Continuous-Wave HOM Load Power Computations Based on Single-Bunch Wake Simulations

Speaker: Hans-Walter Glock (FG-ISRF)

Slides Glock_Benevento_ImpInstWS_20170920.pdf

10:00 Needs and solutions for machine impedance reduction

Speaker: Dr Christine Vollinger (CERN)

Slides CVollingerImpedanceReductionICFA2017.pptx

10:20 Coffee break

10:50 Beam measurements of frequency characteristics of (longitudinal) impedance

Speaker: Dr Alexandre Lasheen (CERN)

Slides ICFA_Benevento_alasheen.pdf

11:10 Beam-based impedance measurement techniques in light sources

Speaker: Dr Ryutaro Nagaoka (Soleil)

Slides R.Nagaoka_Benevento2017.pdf

11:30 Comparison of machine impedance calculation with beam based measurements

Speaker: Karl Bane (SLAC)

Slides kbane_microwave_inst.pdf

11:50 Precise impedance determination from simultaneously measured tunes of unequal charge bunches

Speaker: Dr Boris Podobedov (Brookhaven National Laboratory)

Slides ZtalkBoris.ppt

12:10 An improved method to measure beam impedance with rotating wire. Theoretical and simulation results

Speaker: Mr Olav Berrig (CERN)

Slides The_Rotating_Wire_method.pdf The_Rotating_Wire_method.pptx

12:30 → 14:00 Finger-food lunch at San Vittorino Hall

14:00 → 19:30 Transport to Pompei by bus and visit of Pompei archaeological site

20:00 → 22:30 Social Dinner

22:30 → 23:30 Return to Benevento

Thursday, 21 September

09:00 → 12:10 Session: 4: Instability theory and modeling (Chair: Ingo Hofmann. Scientific secretary: Adrian Oeftiger)

Convener: Prof. Ingo Hofmann (GSI Darmstadt)

09:00 Role of space charge in coherent instabilities

Speaker: Dr Mike Blaskiewicz (BNL)

Slides benevento_talk_blaskiewicz.pdf Blaskiewicz.ppt

09:20 Chromaticity effects on head-tail instabilities for broad-band impedance using two particle model, Vlasov analysis, and simulations

Speaker: Dr Yong Ho Chin (KEK)

Slides Chromaticity_Effects_on_Head-Tail_Instabilities_v3.pptx

09:40 TMCI at strong space charge

Speaker: Dr Timofey Zolkin (Fermi National Accelerator Laboratory)

Slides Zolkin-TMCI.pdf

10:00 Microbunching instability

Speaker: Dr Daniel Ratner (SLAC)

Slides Daniel___ICFA2017.pptx

10:20 Coffee break

10:50 Circulant matrix formalism, benchmarks and beam-beam effect in coherent instabilities

Speaker: Dr Xavier Buffat (CERN)

Slides Xavier___Benevento_circMat-expanded.pdf

11:10 How e-cloud in dipoles and quadrupoles can be source of transverse instabilities

Speaker: Ms Annalisa Romano (CERN)

Slides RomanoAnnalisa.pptx

11:30 Modeling of fast beam ion instabilities

Speaker: Lotta Mether (EPFL)

Slides Benevento_fastion_20170921v1.pptx

11:50 Longitudinal and transverse ions cloud dynamics in an electron ring in presence of electromagnetic fields and gaps

Speaker: Mr Alexis Gamelin (Laboratoire de l’Accélérateur Linéaire (LAL))

Slides ICFA_Ions_v3_mac.pdf ICFA_Ions_v3_mac.pptx

12:10 → 14:00 Lunch Break

14:00 → 17:10 Session 5: Instability modeling, observations and cures (Chair: Mikhail Zobov. Scientific secretary: Eleonora Belli

Convener: Mikhail Zobov (LNF)

14:00 Mitigation of collective effects by optics optimization and the SPS experience

Speaker: Mr Hannes Bartosik (CERN)

Slides 1_HBartosik.pptx

14:20 Simulation of longitudinal intensity effects with LLRF system (BLonD)

Speaker: Dr Helga Timko (CERN)

Slides Benevento_Timko_2017-09.pptx

14:40 Observation and active damping of longitudinal coupled bunch instabilities

Speaker: Heiko Damerau (CERN)

Slides ObservationActiveDampingCoupledBunchInstabilitiesBenevento.pdf ObservationActiveDampingCoupledBunchInstabilitiesBenevento.pptx

15:00 Challenges in impedance and instabilities computation for new generation light sources

Speaker: Serena Persichelli

Slides 4_SPersichelli.pptx

15:20 Coffee Break

15:50 Vlasov solvers and macroparticle simulations

Speaker: Dr Nicolas Mounet (EPFL)

Slides Vlasov_solver_macroparticle_simu_Benevento.odp Vlasov_solver_macroparticle_simu_Benevento.pdf

16:10 Codes benchmarking for the single-bunch instabilities in electron storage rings

Speaker: Dr Haisheng Xu (Institute of High Energy Physics of Chinese Academy of Scineces)

Slides 20170921_IMPED_workshop_HaishengXu.pptx

16:30 Transverse feedback systems for multi-bunch beam diagnostics and instabilities suppression

Speaker: Alessandro Drago (LNF)

Slides Drago_2017.pdf

16:50 Wide-band feedback systems to diagnose and suppress intra-bunch motion in accelerators

Speaker: John Fox

Slides FoxBenevento2017.pdf

18:00 → 19:30 POSTER session

18:00 Preliminary results from validation measurements of the longitudinal power deposition model for the LHC injection kicker magnet

The MKIs are fast pulsed transmission line injection kicker magnets of the LHC injection system. To shield the ferrite yoke from the beam, by providing a path for the beam image current, a set of 24 conductive wires is placed in the inner part of a ceramic tube along the length of the magnet aperture. Stringent rise-time specifications require that the wires are capacitively coupled to a grounded metallic cylinder at the upstream end of the tube, while at the downstream end they can be directly grounded. The cylinder also serves to support a set of nine ferrite rings, placed there to damp low frequency modes that can be excited along the length of the tube. Due to the beam screen design, an open-ended, half-wavelength resonating cavity is formed in the region where the screen conductors overlap with the external metallic cylinder. The so-formed cavity couples to the beam spectrum at discrete frequencies, determined by the length and effective dielectric constant of the cavity. Therefore, the impedance spectrum is resonant in nature exhibiting peaks at the cavity’s resonant frequencies. In order to ensure uninterrupted LHC operation, the MKI ferrite yokes must remain below their Curie temperature at all times. Otherwise, waiting for the yokes to cool down leads to long turn-around times and hence significant deterioration of the overall machine performance. To monitor the temperatures reached within the MKIs 4 thermal probes (PT100) are placed in each magnet: two probes at the upstream and two at the downstream end of the magnet. During Run 1 of the LHC, one of the MKIs occasionally exhibited a high ferrite temperature. An impedance mitigation campaign was launched prior to Long Shutdown 1 (LS1) that led to an effective reduction of the MKI beam coupling impedance and to the corresponding RF heating during Run 2. However, thermal measurements during operation have clearly demonstrated that the upstream end of the magnet is consistently hotter than the downstream one. Power deposition caused by beam induced electromagnetic (e/m) fields due to the coupling of the beam spectrum to the MKI real longitudinal impedance, was identified as the main cause. Nonetheless, the simplified approach of a uniformly distributed power deposition along the length of the magnet was in clear contradiction with the measured data. Therefore, a more detailed description of the power dissipation process had to be looked for and carefully modelled to allow for accurate and robust predictions of current and future kicker beam screen designs; e.g. for HL-LHC. In the present work, the approach followed to obtain estimations for the power loss deposition distributions is presented in detail. The method utilizes sophisticated electromagnetic simulations combined with carefully designed data post-processing to minimize the required simulation data, thus leading to acceptable execution time and storage space per simulation. The method, is then applied to two beam screen designs of the MKI: the one currently in operation and a new one, to be installed as an upgraded version in YETS 17/18. A comparison of the expected power deposition distributions is then carried out and the results are discussed. To validate the predictions of the power deposition model and gain more confidence in the effectiveness of the proposed design, a novel measurement method is proposed and implemented. The method is based on a simple measurement of a transmission coefficient taking advantage of the configuration of the expected e/m modes responsible for RF-heating. Preliminary results of the power deposition measurements are then reported and compared to model predictions.

Speaker: Mr Vasileios Vlachodimitropoulos (CERN)

19:30 → 21:00 Piano Concert

21:00 → 22:30 Dinner

Friday, 22 September

09:00 → 10:20 Session 6 -Instability modeling, observations and cures (Chair: Mikhail Zobov, Scientific secretary: Andrea Passarelli)

Convener: Mikhail Zobov (LNF)

09:00 Damping of transverse instabilities

Speaker: Dr Vladimir Kornilov (GSI Helmholtzzentrum)

Slides Kornilov.pdf

09:20 Concept and simulations of unconventional damping devices: wideband damper and RFQ

Speaker: Dr Kevin Li (CERN)

Slides KevinLi.pptx

09:40 A study of longitudinal effects on transverse Landau damping

Speaker: Prof. Ingo Hofmann (GSI Darmstadt)

Slides Talk-IHofmann.pptx

10:00 Beam Transfer Function (BTF) measurements and transverse stability in presence of beam-beam

Speaker: Ms Claudia Tambasco (EPFL, Lausanne, Switzerland)

Slides BTF_stability_Benevento.pdf

10:20 → 10:50 Coffee break

10:50 → 12:10 SPECIAL SESSION: Overview on different types of machines (Chair: Chris Prior, Scientific Secretary: Adrian Oeftiger)

Convener: Dr Christopher Prior (STFC/RAL/ISIS)

10:50 Impedance and instabilities in lepton colliders

Speaker: Mauro Migliorati (ROMA1)

Slides Migliorati.pdf

11:10 Impedance and instabilities in hadron machines

Speaker: Benoit Salvant (CERN)

Slides Benevento-Bsalvant-_impedance_hadron_machines_v4.pptx

11:30 Impedance modeling in low emittance rings

Speaker: Dr Alexei Blednykh (BNL)

Slides Blednykh.pdf

11:50 Instabilities in hadron colliders and role of the transverse damper

Speaker: Dr Alexey Burov (Fermilab)

Slides Beam_Stability_in_Colliders.pdf

12:10 → 13:30 Farewell lunch at San Vittorino complex

13:30 → 15:00 Session 7: Conclusions (Chair: Stefania Petracca)

Convener: Stefania Petracca (SA)

13:30 Closing remarks of Session 2: Impedance theory and modeling

Speaker: Ursula Van Rienen (uni Rostock)

Slides Ursula_-_Closing_remarks_Session_2.pdf

13:45 Closing remarks of Session 3: Impedance measurements and control

Speaker: Maria Rosaria Masullo (NA)

Slides Iaia-sommario.pptx

14:00 Closing remarks of Session 4: Instability theory and modeling

Speaker: Prof. Ingo Hofmann (GSI Darmstadt)

Slides INGO-session4_summary.pdf

14:15 Closing remarks of Session 5: Instability modeling, observations and cures

Speaker: Mikhail Zobov (LNF)

Slides Mikhail.pptx

14:30 Closing remarks, acknowledgements and goodbye

Speaker: Dr Giovanni Rumolo (CERN)

Slides Rumolo.pptx

15:30 → 16:30 Transfer to Naples airport (15:30)