chaired by Roberto Cimino (LNF), Frank Zimmermann (CERN), Roberto Cimino
from to (Europe/Rome)
at Italy, La Biodola Bay, Isola d'Elba

The sixth electron-cloud workshop, ECLOUD'18, will take place from 3 to 7 June, 2018 at La Biodola (Isola d'Elba) Italy. The existence of the electron-cloud effects (ECE’s) has been firmly established experimentally at essentially all modern positron and hadron storage rings, either via performance limitations or by deliberate provocation. The ECE is a consequence of the strong coupling between a positively charged particle beam and a cloud of electrons that inevitably develops inside the vacuum chamber. Resulting deleterious effects include beam instabilities, beam losses, emittance growth, increases in vacuum pressure, additional heat load on the vacuum chamber walls, and interference with certain types of beam diagnostics.

Electron-cloud effects remain dynamical phenomena which are only incompletely understood. While the fundamental mechanisms are well recognized and the qualitative picture is clear, the phenomena involve many surface properties and geometrical parameters of the vacuum chamber coupled in a nontrivial way with the beam characteristics. The ECE can also conspire with classical wake-field effects and/or the beam-beam interaction. In addition, the relevant time and energy scales span a wide range, and many of the essential parameters are not well known a priori. Hence the detailed prediction of ECE's at a given machine, not to mention the extrapolation from one machine to another, are subject to great uncertainty.

High-power microwave applications in modern satellites are perturbed by phenomena of multipacting and RF breakdown, which are governed by the same surface parameters as ECE in accelerators. Especially for multi-carrier signals, they exhibit very similar characteristics and electron-cloud build-up time scales, and can be modelled by similar simulation tools.

Since the last successful workshop ECLOUD’12, which also took place in La Biodola (Isola d'Elba) Italy, an intense R&D effort has been under way to further understand the physics of the electron cloud and to investigate new methods for the mitigation of its adverse consequences.

Electron cloud remains a major concern for the High Luminosity LHC and even for the actual LHC run 2. At CERN and worldwide a significant effort is also dedicated to the study of Future Circular Collider (FCC) options – involving both proton and electron-positron colliders which may suffer from electron cloud. As a consequence of the high synchrotron radiation, large bunch charge, and close bunch spacing in several of the FCC machines, the ECE’s are expected to be significant. It is urgent to better quantify and understand the associated phenomena to ascertain the feasibility of the performance goals. ECE’s have been noticeable during the first commissioning run of SuperKEKB in 2016. The next commissioning run from early 2018 onward will further raise the beam intensity.

The ECLOUD'18 workshop will be a timely meeting at which to present, discuss, and compare many recent and new electron-cloud observations at the LHC, SuperKEKB, CESR-TA and DAFNE, electron cloud predictions for FAIR, NICA and for the FCC.  The ECLOUD’18 workshop will also showcase and examine electron-cloud mitigation measures, such as clearing electrodes, graphite/carbon coatings, and chemically or laser treated surfaces, along with the modeling of incoherent electron-cloud effects, self-consistent simulations, synergies with other communities like the Valencia Space Consortium and the European Space Agency.

The ECLOUD'18 program will focus on: a review of EC observations at existing machines; recent experimental efforts to characterize the EC (including EC diagnostics, experimental techniques, characterization of mitigation methods, and characterization of beam instabilities and emittance growth); the status of EC physics models and simulation codes and their comparison with recently acquired experimental data; and the mitigation requirements and potential performance limitations imposed by the EC on existing, upgraded and future machines.
ECLOUD'18 will be held at the Hermitage Hotel in La Biodola, Isola d'Elba. We are looking forward to an exceptional gathering where we can enjoy the beautiful location, have interesting scientific discussions about the state of the art, and initiate stimulating collaborations among electron-cloud key experts as well as with students and other scientists from neighbouring fields.

The meeting is sponsored by:

Istituto Nazionale di Fisica Nucleare (INFN)



Go to day
  • Sunday, 3 June 2018
    • 18:15 - 19:00 Electron cloud effects (ECEs) in accelerators 45' ( Sala Maria Luisa, Hotel Hermitage, chaired by Roberto Cimino )
    • 19:00 - 21:00 Welcome party and dinner ( By the pool, Hotel Hermitage restaurant )
  • Monday, 4 June 2018
    • 08:30 - 10:20 ECE on Beam Dynamics: observations and prediction (I)
      Location: Sala Maria Luisa (SML), Hotel Hermitage
      • 08:30 E-cloud Effects in CERN accelerator Complex 30' ( SML, Hotel Hermitage )
        Speaker: Dr. Giovanni Rumolo (CERN)
      • 09:00 Coupled-bunch instabilities and related effects due to electron cloud in SuperKEKB LER 30' ( SML, Hotel Hermitage )
        Speaker: Dr. MAKOTO TOBIYAMA (KEK Accelerator Laboratory)
      • 09:30 E-cloud observations and simulation at J-PARC 30' ( SML, Hotel Hermitage )
        Speaker: Dr. kazuhito ohmi (KEK)
      • 10:00 Positron vs electron Beam behavior at PETRA 20' ( SML, Hotel hermitage )
        Speaker: Rainer Wanzenberg (DESY)
    • 10:20 - 10:50 Coffee break ( Parking Area, Hotel Hermitage )
    • 10:50 - 13:00 ECE on Beam Dynamics: observations and prediction (II)
      Location: Sala Maria Luisa (SML), Hotel Hermitage
      • 10:50 Measurements and simulations of electron-cloud-induced tune shifts and emittance growth at CesrTA 30' ( SML, Hotel Hermitage )
        Speaker: Dr. Stephen Poprocki (Cornell University)
      • 11:20 RHIC instabilities at transition crossing (su) 30' ( SML, Hotel Hermitage )
        Speaker: Xiaofeng Gu (Brookhaven National Lab)
      • 11:50 Electron cloud challenges for future circular machines 30' ( SML, Hotel hermitage )
        Speaker: Lotta Mether (EPFL)
      • 12:20 Investigating the role of photoemission in the e-cloud formation at the LHC 20' ( SML, Hotel Hermitage )
        Speaker: Mr. Philipp Dijkstal (Paul Scherrer Institut)
      • 12:40 E-cloud studies for FCC-hh 20' ( SML, Hotel Hermitage )
        Speaker: Ms. Daria Astapovych (TU Darmstadt)
    • 13:00 - 15:50 Lunch break ( Fuoco di Bosco, Hotel Hermitage )
    • 15:50 - 17:40 ECE effects on vacuum and heat load (I)
      Convener: Dr. Giovanni Rumolo (CERN)
      Location: Sala Maria Luisa (SML), Hotel Hermitage
      • 15:50 An overview on heat loads in the LHC 30' ( SML, Hotel Hermitage )
        Speaker: Dr. Giovanni Iadarola (CERN)
      • 16:20 Effect of synchrotron radiation and chamber properties on LHC electron-cloud heat load 20' ( SML, Hotel Hermitage )
        Speaker: Mr. Gerardo Guillermo (CERN (BE))
      • 16:40 Electron cloud build up in two-beam regions for HL-LHC, heat load and vacuum aspects 20' ( SML, Hotel Hermitage )
        Speaker: Ms. Annalisa Romano (CERN)
      • 17:00 Dynamic pressure related to electron cloud during Run2 machine operation in the LHC 20' ( SML, Hotel Hermitage )
        Speaker: Dr. Christina Yin Vallgren (CERN)
      • 17:20 How does a cryogenic system cope with e-cloud induced heat load? what can we learn from heat load measurements (including evolution, transients, etc)? 20' ( SML, Hotel Hermitage )
        Speaker: Mr. Benjamin Bradu (CERN)
    • 17:40 - 18:00 Coffee break ( Parking Area, Hotel Hermitage )
    • 18:00 - 19:30 ECE Effects on Vacuum and heat load (II)
      Location: Sala Maria Luisa (SML), Hotel Hermitage
      • 18:00 Impedance issues in ECE research 30' ( SML, Hotel Hermitage )
        Speaker: Benoit Salvant (CERN)
      • 18:30 Experimental challenge in linear and circular accelerators driven by impedance issues 20' ( SML, Hotel Hermitage )
        Speaker: Prof. Andrea Mostacci (Sapienza)
      • 18:50 SubTHz EM characterization of coated material 20' ( SML, Hotel Hermitage )
        Speaker: Vittorio Giorgio Vaccaro (NA)
      • 19:10 Instability caused by e-cloud in combined function magnets: the FERMILAB experience 20' ( SML, Hotel Hermitage )
        Speaker: Dr. Sergey Antipov (CERN)
    • 20:00 - 22:00 Dinner ( Hotel Hermitage restaurant )
  • Tuesday, 5 June 2018
    • 08:30 - 10:30 Surface properties, coating and experimental studies (I)
      Location: SML, Hotel Hermitage
      • 08:30 SEY: what we know and what we still need to know 30'
        Speaker: Dr. Mauro Taborelli (CERN)
      • 09:00 SEY measurements of coated surfaces with different coating thickness 20'
        Speaker: Mrs. Eleonora Belli (CERN)
      • 09:20 Characterisation of beam screens extracted from LHC magnets 20'
        Speaker: Mrs. Valentine Petit (CERN)
      • 09:40 SEY studies at CSNS 20'
        Speaker: Ms. Shenghua Liu (Institute of High Energy Physics,Chinese Academy of Sciences)
      • 10:00 Stainless Steel SEY: A controversial story 10'
        Speaker: Roberto Cimino (LNF)
      • 10:10 SEY from noble metals 10'
        Speaker: Luis Antonio Gonzalez Gomez (LNF)
      • 10:20 SEY from the LASE surfaces with and without absorbed gases at cryogenic temperatures 10'
        Speaker: Mr. Bhagat-Taaj Sian (STFC)
    • 10:30 - 11:00 Coffee break ( Parking Area, Hotel Hermitage )
    • 11:00 - 13:00 Surface properties, coating and experimental studies (II)
      Convener: Dr. Mauro Taborelli (CERN)
      Location: SML, Hotel Hermitage
      • 11:00 A surface Science approach to SEY studies 20'
        Speaker: Dr. Rosanna Larciprete (CNR-ISC/LNF-INFN)
      • 11:20 Photo reflectivity and PEY of technical surfaces 20'
        Speaker: Andrea Liedl (LNF)
      • 11:40 Photons Interaction with technical surfaces 20'
        Speaker: Marco Angelucci (LNF)
      • 12:00 Low SEY surface modelling with VSim’ 20'
        Speaker: Dr. Jonathan SMITH (Tech-X UK Ltd)
      • 12:20 MC Simulation of SEY for Noble metals 20'
        Speaker: Martina Azzolini (ECT* -FBK-Universita' degli studi di Trento)
      • 12:40 Low-secondary electron emission coatings for ESA´s Galileo 20'
        Speaker: Prof. ISABEL MONTERO (ICMM-CSIC)
    • 13:00 - 15:00 Lunch break ( Fuoco di Bosco, Hotel Hermitage )
    • 15:00 - 16:50 Multipactoring and related effects
      Location: SML, Hotel Hermitage
      • 15:00 SEY properties in Plasma research, modelling and measurements 30'
        Speaker: Dr. Igor Kaganovich (PPPL)
      • 15:30 Recent advances on multipactor effect in satellites comunications RF 20'
        Speaker: Prof. Gimeno Martinez Benito (University of Valencia)
      • 15:50 SEY properties of dielectric materials, modelling and measurements 20'
        Speaker: Mr. Mohamed Belhaj (ONERA)
      • 16:10 Experiments with stable confined electron columns 20'
        Speaker: Ms. Katrin Isabell Thoma (Goethe Universität Frankfurt)
      • 16:30 Multipactoring in the RF structures 20'
        Speaker: Dr. Nasrin Nasresfahani (CERN)
    • 16:50 - 17:10 Coffee break ( Parking Area, Hotel Hermitage )
    • 17:10 - 18:40 Electron and photon interaction with low temperature surfaces
      Location: SML, Hotel Hermitage
      • 17:10 SR interaction with cryosorbed layers 30'
        Speaker: Mr. Rémi Dupuy (LERMA (Sorbonne Université, Obs. Paris))
      • 17:40 SEY and other material properties studies at cryogenic temperatures 20'
        Speaker: Luisa Spallino (LNF)
      • 18:00 Characterisation of technical surfaces at cryogenic temperature under electron bombardment 20'
        Speaker: Mr. Bernard Henrist (CERN)
      • 18:20 Coldex: A tool to study cold surfaces in Accelerators 20'
        Speaker: Dr. Vincent Baglin (CERN)
    • 19:00 - 20:00 Football match ECE Theory vs ECE Experiment ( Soccer field, Hotel Hermitage )
    • 20:30 - 23:30 Social dinner and dance ( Restaurant Maitù )
  • Wednesday, 6 June 2018
    • 09:00 - 10:30 Simulations and diagnostics (I)
      Location: SML, Hotel Hermitage
      • 09:00 Progress with 3D modelling of beam dynamics in presence of electron cloud 30'
        Speaker: Jean-Luc Vay (Berkeley Lab)
      • 09:30 Post-ecloud regime, challenges for multi-species simulations in beam dynamics 30'
        Speaker: Lotta Mether (EPFL)
      • 10:00 A global view on electron cloud instability simulations in the LHC and HL-LHC 30'
        Speaker: Ms. Annalisa Romano (CERN)
    • 10:30 - 11:00 Coffee break ( Parking Area, Hotel Hermitage )
    • 11:00 - 13:00 Simulations and diagnostics (II)
      Location: SML, Hotel Hermitage
      • 11:00 E-cloud challenges at SuperKEKB and future colliders 30'
        Speaker: Dr. kazuhito ohmi (KEK)
      • 11:30 Simulations of synchrotron-radiation-induced electron production in the CESR vacuum chamber wall 30'
        Speaker: James Crittenden (Cornell University)
      • 12:00 Secondary Emission Models in e-cloud buildup simulations: from the lab to the code 20'
        Speaker: Dr. Luca Sabato (CERN)
      • 12:20 Preliminary results obtained with the LHC Vacuum Pilot Sector 20'
        Speaker: Ms. Elena Buratin (CERN)
      • 12:40 DAFNE&ecloud: observations and prospective 20'
        Speaker: Catia Milardi (LNF)
    • 13:00 - 15:50 Lunch break ( Fuoco di Bosco, Hotel Hermitage )
    • 15:50 - 17:20 Mitigation (I)
      Location: SML, Hotel Hermitage
      • 15:50 ECE and its cures in the SuperKEKB positron ring 30'
        Speaker: Dr. Yusuke Suetsugu (High Energy Accelerator Research Organization (KEK))
      • 16:20 SEY lowering with a-C coating in SPS and LHC 20'
        Speaker: Pedro Costa Pinto (CERN)
      • 16:40 Laser Ablated Surface Engineering (LASE) for e-cloud mitigation: from discovery to machine application 20'
        Speaker: Dr. reza valizadeh (ASTeC, STFC)
      • 17:00 Low SEY LASE and NEG coated surfaces and their surface resistance, vacuum properties and particulate generation’ 20'
        Speaker: Dr. Oleg Malyshev (STFC Daresbury Laboratory)
    • 17:20 - 17:40 Coffee break ( Parking Area, Hotel Hermitage )
    • 17:40 - 18:40 Mitigation (II)
      Convener: Dr. Oleg Malyshev (STFC Daresbury Laboratory)
      Location: SML, Hotel Hermitage
      • 17:40 SEY, pumping properties and surface resistance of new high electric conductivity NEG coating’ 20'
        Speaker: Mr. adrian hannah (STFC ASTeC)
      • 18:00 In-situ coating and scrubbing of long narrow beam pipes for eliminating electron clouds and reducing vacuum wall RF resistivity 20'
        Speaker: Dr. Ady Hershcovitch (BNL)
      • 18:20 Intrabunch feedback system development at Dafne 20'
        Speaker: Alessandro Drago (LNF)
    • 18:40 - 19:20 Outlook and conclusion
      Location: SML, Hotel Hermitage
      • 18:40 ECLOUD18 Summary and Outlook 20' ( Sala Elena, Hotel Hermitage )
        Speaker: FRANK ZIMMERMANN (CERN)
      • 19:00 ECLOUD18 Closing remarks 20' ( Sala Elena, Hotel Hermitage )
        Speaker: Roberto Cimino (LNF)
    • 20:00 - 22:00 Dinner ( Hotel Hermitage restaurant )