1. WG-1 Session Cavity Performance Cryomodule Performance
Data (near future/ Large scale)
Low Beta performance

2. WG1-Session1 Cavity Performance
Camille Ginsburg (FNAL), John Mammosser (JLAB)

3. Five talks were presented covering recent cavity vertical test RF performance from:
KEK STF-2 cavities (Yamamoto)
JLab 12GeV cavities (Reece)
DESY XFEL cavities (Reschke)
FNAL ILC/ProjectX cavities (Ginsburg/Ozelis)
FNAL/ANL and KEK facilities, processes and procedures are a fully functional for state of the art gradients
R&D is well underway for further developments

6. What can we take for the data presented:
Gradients greater then 25MV/m were easily and consistently met from all labs (KEK, DESY, FNAL, JLAB)
Field emission is present in most data but not always the limit
Still a few low gradient FE onsets (accidents) in all data
Example FNAL 38 9-cell tests 2010 (FNAL and some JLab)
Radiation detector location and shielding different at each lab but do the data shows similar spread?

7. Additionally: Many vertical cavity tests being performed
A very good opportunity to capture data and gain understanding
Good diagnostic methods being applied, example is KEK (optical & thermal)
Need to continue to track FE, still present in most tests
Field emission is usually recovered by HPR but not always (statistics are needed to further understand limits)?
Small number of incidents still occur which affect cavity performance

8. Questions to the SRF community:
Are we capturing the enough data to understand limits?
Are the data compatible / comparable?
What should be changed?

9. WG1-Session2 Low Beta Cavity Performance
Paolo Pierini (INFN), John Mammosser (JLAB)

10. Four talks were presented covering recent low beta cavity activities from:
ESS (R&D Plans CEA) G. Devanz
IAP (SC activities) M. Busch
Project-X (Cavities/tuner FNAL) L. Ristori
ESS (RF simulations at RHUL) S. Molloy

11. ESS (R&D Plans CEA) G. Devanz
Double spoke resonators
Frequency = MHz
Beta = 0.53
Challenges: • High gradients ( 8 MV/m ) • High peak power couplers (~ 400 kW nominal) • Pulsed operation • Series production of spoke cavities (real 3D geometry and performance reproducibility) • Open questions : HOM Operation T° (2K or 4K) Cryomodule type …

12. Main contributors for prototypes
CNRS/IN2P3/IPN Orsay (France): cavities (2 prototypes), couplers ( 2proto types), tuners, cryomodule, preparation and test facility, WP coordination
ESS BILBAO/TEKNIKER (Spain): cavities, tuners, engineering design (mechanical, RF)
JLAB (USA) : Discussion in progress for a plug- compatible cavity design and prototype, independent cryomodule design

13. ESS design and prototyping activities at CEA-Saclay
High beta (0.86) 704 MHz 5-cell cavities, 2 prototypes
HOM couplers
1 MW power couplers, 2 prototypes
Magnetic shielding
Combined fast/slow tuner
Design update ( )
RF Conceptual design of the cavity
6 high beta (0.86) 704 MHz 5-cell cavities with HOM couplers, tuner, magnetic shielding, power coupler
Fabrication, preparation conditioning and test of all elements
P2B ( )

14. Collaboration on ESS elliptical cavities
CEA-Saclay : high beta cavities, power couplers, tuners
ESS-AB : cryomodule and cryogenics
Lund-U : medium beta cavities
Rostock : HOM (RF WP8)
RHUL : HOM, complex RF and multipacting simulations (RF WP8)
CERN : 704 MHz test area, 4-cavity cryomodule test (beta=1 cavities)
Upsala : Fully equiped test stand with horizontal cryostat
Jlab and DESY : On going discussions for cryomodule conceptual design comparisons

15. SC activities IAP Frankfurt
Prototyping
RF Qualification
325MHz CH cavity prototyping and RF testing

16. CH Cavity Vertical Test Results

17. Low Beta cavities and tuner development FNAL
325 MHz SSR1 Design
Cavity designed and modeled
RF model + Mechanical Design
Prototypes were fabricated industry
Tuning and trimming
Processing
Vertical RF testing
Helium jacket completed
Horizontal RF testing

18. SSR1 RF Test Results: Vertical test results
Horizontal Test – excellent results
Tuner Developed

19. ESS Cavity RF Modeling (Royal Holloway):

20. Development of a simplified model:

21. Summary of WG session:
Low Beta cavity projects are active and developing in all regions
Cavity design
Modeling
Fabrication
Testing (Good Performance)
Horizontal and vertical