MeVArc 2010 Workshop

6 May 2010, 08:00 → 7 May 2010, 18:30 Europe/Zurich

40/S2-D01 - Salle Dirac (CERN)

Sergio Calatroni (CERN), Flyura Djurabekova (University of Helsinki), Kai Nordlund (University of Helsinki), Walter WUENSCH (CERN)

Vacuum breakdowns caused by high voltages and high-power rf are extremely complex phenomena, however significant advances understanding and quantitative modeling are being made. The latest developments in theory, simulation, supporting experimental investigations and application to high-gradient device design will be covered in this workshop. The workshop seeks to bring together the diverse communities such as accelerators, plasma fusion and satellite communication which must contend with vacuum breakdown. This workshop will be preceded by a meeting on the development of high-power X-band rf structures (X-Band Structure) for CLIC.

Thursday, 6 May

09:00 → 12:40 Introduction and general physics

09:00 Welcome address

Speaker: Jean-Pierre Delahaye (CERN)

09:10 Introduction to CLIC and breakdown in rf structures

Speaker: Walter WUENSCH (CERN)

Slides breakdown_in_rf_ww.pdf breakdown_in_rf_ww.pptx

09:30 Discussion

09:40 BD problem in satellites

Speaker: David Raboso

10:00 Discussion

10:10 Arc surface damage in fusion reactors

Speaker: Volker Rohde

Slides rohde_cern1005.pdf

10:30 Discussion

10:40 Coffee Break and posters

11:10 Physics of arc plasma devices

Speaker: Andre Anders

Slides Anders_cathodicArcs2010-05-04.pdf

11:30 Discussion

11:40 Challenges simulating low temperature collisional plasmas

Speaker: Matthew Hopkins (Sandia National Laboratories)

Slides

• 4-way-solution-2D-shaped-2008-06-22.avi
• Ar+-3D-shaped.avi
• Hopkins_CERN_2010_presentation_2010-04-25.ppt
• proc-ids-3D-shaped-2008-06-23.avi
• proc_ids.avi

12:00 Discussion

12:10 Distinguishing between work function and geometric field enhancement effects in field emission

Speaker: Dr Wei Gai (Argonne National Laboratory)

Slides BA2007-schottky.pdf BA2007-schottky.ppt

12:30 Discussion

12:40 → 14:00 Lunch

14:00 → 18:00 Experiments and diagnostics

14:00 DC breakdown measurements

Speaker: Mr Sergio Calatroni (CERN)

Slides DCSpark-BreakdownWorkshop.pdf DCSpark-BreakdownWorkshop.pptx

14:20 Discussion

14:30 The Electric Dipole Moment of the proton in an all electric storage ring

Speaker: Dr Yannis Semertzidis (BNL)

Slides YkS_CERN_20100506.pdf YkS_CERN_20100506.ppt

14:50 Discussion

15:00 Breakdown experiments simulations in waveguides

Speaker: Dr Valery Dolgashev (SLAC)

Slides

• Breakdown_PIC_simulations_CERN_1402_4May2010.pdf
• Breakdown_PIC_simulations_CERN_1402_4May2010.pptx
• movies.zip

15:20 Discussion

15:30 High gradient electrodes for pulsed electron gun

Speaker: Martin Paraliev (PSI)

Slides Experimental Study of DLC Coated Electrodes for Pulsed Electron Gun

15:50 Discussion

16:00 Coffee break and posters

16:30 Spectroscopy of breakdowns

Speaker: Jan Kovermann (III. Physikalisches Institut (B) - Rheinisch-Westfaelische Tech.)

Slides BDWS2010.pdf BDWS2010.pptx

16:50 Discussion

17:00 Breakdown-related Surface Evaluation by Scanning Field Emission Microscope

Speaker: Yasuo Higashi (KEK)

Slides Breakdown_physics_workshop100505Higashi.pdf Breakdown_physics_workshop100505Higashi.ppt

17:20 Discussion

17:30 In-situ breakdowns in SEM

Speaker: Roger Ruber (University of Uppsala)

Slides vz-sem-20100506.pdf vz-sem-20100506.ppt

17:50 Discussion

Friday, 7 May

08:00 → 12:30 Theory and simulation

09:00 Multiscale model

Speaker: Flyura Djurabekova (University of Helsinki)

Slides BD_WSh_djurabekova.pdf BD_WSh_djurabekova.pptx

09:20 Discussion

09:30 PIC plasma and MD simulations

Speaker: Helga Timko (Univ. of Helsinki, Fac. of Science-Unknown-Unknown)

Slides BRD10_timko.pdf BRD10_timko.ppt

09:50 Discussion

10:00 Dark current calculations in RF structures

Speaker: Arno Candel (SLAC National Accelerator Laboratory)

Slides Breakdown10_Candel.pdf Breakdown10_Candel.pptx

10:20 Discussion

10:30 Coffee break and posters

11:00 Arc simulations using Aleph, a PIC/DSMC code

Speaker: Paul Crozier

Slides

• arc_simulations_using_Aleph.pdf
• arc_simulations_using_Aleph.ppt
• density_37.wmv
• potential_37.wmv

11:20 Discussion

11:30 Arc modeling at Sumy, Ukraine

Speaker: Dr Serhiy Mordyk (of Applied Physics National Academy of Sciences of the Ukraine)

Slides iap_nasu2010.pdf iap_nasu2010.ppt

11:50 Discussion

12:00 New results from arc modeling and our workshop on Unipolar Arcs

Speaker: Mr Jim Norem (Argonne National Lab)

Slides CERN_May_7_norem.pdf

12:20 Discussion

12:30 → 14:00 Lunch

14:00 → 18:00 Pulsed surface heating experiments & Theory

14:00 Pulsed surface heating and BDR

Speaker: Chris Adolphsen (SLAC)

Slides Adolphsen_Pulse_Heating.pdf Adolphsen_Pulse_Heating.ppt

14:20 Discussion

14:30 Introduction to dislocations dynamics

Speaker: Steve Fitzgerald

Slides Apologies for lack of animations

14:50 Discussion

15:00 Coffee break and posters

15:30 Asperities on the surface due to dislocations activity

Speaker: Aarne Pohjonen (University of Helsinki)

Slides Pohjonen_CLIC070510-15.pdf

15:50 Discussion

16:00 Metallurgy of pulsed surface heating

Speaker: Markus Aicheler (Ruhr-Universitaet Bochum)

Slides MAicheler_BDWS_2010_05_07.pdf MAicheler_BDWS_2010_05_07.pptx

16:20 Discussion

16:30 Experimental Evaluation of Magnetic Field Effects on Breakdown Rates

Speaker: Prof. Sami Tantawi (SLAC)

Slides Mag1.pdf Mag1.pptx

16:45 Discussion

16:50 New features observed with SEM in-lens detector in the vicinity of breakdown craters

Speaker: Gonzalo Arnau Izquierdo (CERN)

Slides New_features_observed_with__SEM_in-lens_detector_in.pdf New_features_observed_with__SEM_in-lens_detector_in.ppt

17:10 Disscussion

17:20 Announcementof workshop 2011

Speaker: Kai Nordlund (University of Helsinki)

Slides breakdown11_welcome.pdf breakdown11_welcome.pptx