HOM issues in the ESS SC linac

22 Sept 2011, 08:45 → 23 Sept 2011, 13:00 Europe/Stockholm

Auditorium, 1st floor (European Spallation Source)

Stephen Molloy (ESS)

HOM issues in the ESS SC linac, including discussions on the likely HOM spectrum for each cavity family, beam dynamics issues, coupler design, and the risks/benefits of installing couplers. The output of this meeting will include plans for a program of simulation studies, a program of hardware measurements, possible impacts on the planning of test stands, and input to the CDR.

Thursday, 22 September

Coffee and registration

Welcome

Introduction to the meeting, and definition of the goals

Convener: Stephen Molloy (ESS)

1 Introduction and Welcome

Speaker: David McGinnis (ESS)

2 Meeting goals

Speaker: Stephen Molloy (ESS)

Slides molloygoals.pdf molloygoals.pptx

Beam parameters & cavity design

The design of the ESS SC cavities, their RF properties, and a discussion of HOM impact on beam quality

Convener: David McGinnis

3 ESS time structure & bunch length

Speaker: Håkan Danared (ESS)

Slides danared.pdf danared.pptx

4 Considerations of cavity design

Speaker: Rama Calaga (Brookhaven National Laboratory (BNL))

Slides HOM_Sep22_2011.pdf

5 Elliptical cavity design

Speaker: guillaume devanz

Slides HOMmeeting_-sept-2011.pdf

10:40 Coffee

Beam parameters & cavity design

The design of the ESS SC cavities, their RF properties, and a discussion of HOM impact on beam quality

Convener: David McGinnis (ESS)

6 Spoke cavity design

7 Beam dynamics due to HOMs

Speaker: Marcel Schuh (CERN)

Slides 2011-ESS-HOM-WS.pdf

Lunch

HOM couplers

Convener: Stephen Molloy (ESS)

8 Studies of HOMs in Elliptical and Spoke Cavities for ESS

Speaker: Roger Jones (University of Manchester, Cockcroft Institute)

Slides RM_Jones_ESS_RF_WS__Sept_2011.pdf RM_Jones_ESS_RF_WS__Sept_2011.pptx

9 HOM coupler design

Speaker: Hans-Walter Glock (Rostock)

Slides ESS_Lund_URos_Glock_110922.key ESS_Lund_URos_Glock_110922.pdf

10 Discussion

15:00 Coffee

HOM coupler risks

A discussion of the risks presented by the installation at other machines, including experiences from SNS

Convener: Deepak Raparia

11 Coupler multipactor

Speakers: Robert Ainsworth (RHUL), Stephen Molloy (ESS)

Slides ainsworth.key ainsworth.pdf

12 Discussion

Friday, 23 September

Coffee

13 Summary of day 1

Speaker: Stephen Molloy (ESS)

Discussion - Simulation studies

Build a prioritised list of required simulations (small & large-scale)

Convener: Stephen Molloy (ESS)

14 MP & FE in Vorpal

Speaker: Jonathan Smith (Tech-X)

15 Multi-cavity effects

Speaker: Stephen Molloy (ESS)

Slides molloymultipleCavities.pdf molloymultipleCavities.pptx

10:45 Coffee

Discussion - Studies at test stands

Build a prioritised list of tests to be performed at future ESS test stands.

16 HOMs as beam diagnostics

Speaker: Nicoleta Baboi (DESY)

Slides 2011.09.22-23_ESS-HOM_HOMBPMs.pdf 2011.09.22-23_ESS-HOM_HOMBPMs.pptx

Discussion - Drawing conclusions

Respond to the questions raised at the start of the meeting, and any other questions raised along the way (listed in today's summary talk).

Convener: David McGinnis (ESS)