EuCARD-2 is co-funded by the partners and the European Commission under Capacities 7th Framework Programme, Grant Agreement 312453

Co-ordinators:Peter McIntosh (STFC Daresbury Laboratory)

Wolf Dietrich-Moller (DESY)Juliette Plouin (CEA)

WP12: Innovative RF Technologies

EUCARD-2 Steering CommitteeDaresbury Laboratory, 12 – 13 Dec 2013

WP12 Task Activities

Task 12.2SRF Thin FilmsClaire Antoine (CEA)

Task 12.3High Gradient NCWalter Wuensch (CERN)

Task 12.4SRF HOM Beam Diagnostic Roger Jones (Man. Univ.)

Task 12.5RF PhotocathodesRobert Nietubyc (NCBJ)

Task 12.1WP12 ManagementPeter McIntosh (STFC)

WP12 Milestones

Milestone Title Beneficiary Date Comments

MS87 Fundamental SRF Thin Film physics report CEA M48 Final Activity Report

MS84 Deposition test facility designed at CEA. CEA M40 Facility designed and validated

MS78 Characterisation test facility implemented at HZB HZB M30 Facility implemented and validated

MS88Report summarising the results obtained in characterising the various new thin film technologies developed, which include both multilayer and monolayer techniques

CEA M48 Final Activity Report

MS81 RF design CLIC_DDS_B UNIMAN M36 Activity Report.

MS86 RF design of fully interleaved structure and CLIC SW study. UNIMAN M45 Activity Report. Concluding final report

MS76 High power RF components fabricated and tested at low level CEA M24 Prototype completed and validated

MS74 Design concept RF front end PSI M12 Activity Report

MS77 Phase stabilisation experiment design ULANC M24 Activity Report

MS79 Crab cavity electromagnetic design ULANC M30 Activity Report

MS82 Completed coupled cavity simulations of 8-cavity module UNIMAN M36 Activity Report

MS80 Demonstrated operation of improved deposition system, Pb layers of 1 μm in thickness. NCBJ M30 Report on sample characterisation

MS73 Commissioning of the SAPI for operation with metal photocathodes STFC M8 Publication report

MS75 Investigation of quantum yield and energy spectrum of the electrons, emitted from the metal photocathode surface in SAPI STFC M18 Intermediate scientific report

MS83 Manufacturing and commissioning of the photocathode transport system STFC M36 Technical design report

MS85 Investigation of the brightness of different metal photocathodes in a S-band NCRF gun STFC M42 Scientific report

Task 12.2

Task 12.3

Task 12.4

Task 12.5

WP12 Deliverables

Deliverable Title Beneficiary Date Comments

D12.1 Deposition test facilities implemented and verified at CERN and INPG. CERN M18 Report

D12.5 First resonator deposited and qualified at CERN. CERN M36 ReportD12.10 Cavity deposited and qualified at CEA. CEA M48 ReportD12.2 Initial progress report of task 12.3. CERN M18 ReportD12.6 Intermediate progress report of task 12.3. CERN M36 Report

D12.11 Final report of task 12.3. CERN M48 ReportD12.3 Design of electronics for XFEL HOM diagnostics. DESY M18 Report

D12.7 Completed characterisation of HOMs in the 8-cavity XFEL 3HC module. UNIMAN M36 Report

D12.12 Report on characterisation of HOMs in XFEL coupled 3HC cryomodule. UNIMAN M48 Report

D12.4 Scientific report on photocathode R&D. STFC M18 Report

D12.8 Optimised procedure for microdorplets flattening with an UV laser. NCBJ M36 Report

D12.9 Pb/Nb plug photocathodes measurements and characterization. HZDR M42 Report

D12.13 Results of DAC implementation in SRF guns. HZB M48 Report

Task 12.2

Task 12.3

Task 12.4

Task 12.5

Task 12.1 Management

• Task Kick-off Meetings:– 12.2 Thin Films @ CERN on 14th June 2013.– 12.3 High Gradient NC by telecon on 30th May 2013:

• http://indico.cern.ch/conferenceDisplay.py?confId=251925

– 12.4 SRF HOM Diagnostics – same team transition from EUCARD. – 12.5 RF Photocathodes @ HZB Berlin on 12th July 2013:

• https://espace.cern.ch/eucard2-intranet/WP12/12.5/default.aspx

• Reviews scheduled/completed:– 12.2 Thin Films – Meetings held @ SRF2013, Paris in Sep 2013– 12.3 High Gradient NC – 4 Feb 2014 @ CLIC Workshop, CERN– 12.4 SRF HOM Diagnostics – To be arranged– 12.5 RF Photocathodes – To be arranged– WP12 Annual Review – Expected 1 Apr 2014, location TBD

Task 12.2 Thin Films

CEA Saclay• First set of experiments using refurbished magnetometer done up to 140

mT. Latest measurements presented at SRF2013.– Further improvements are foreseen (enable larger samples, new coil

design).• Campaign to hire post doc started.

INP Grenoble• ALD deposition set-up designed and under fabrication (expected for Q1

2014).• Series of NbN samples have been CVD deposited and undergoing

characterization.• Difficulties in hiring PhD student (absence of funding), some delays

expected.

Task 12.2 Thin Films

CERN• Refurbishing of cavity production chain

(surface treatments, etc.) in progress:– Vertical EP for copper cavities

1.3/1.5 GHz is now fully operational.

• Two cavities have been HIPIMS coated:– Performance equivalent to the

best cavities coated in the past by magnetron. (plot shown, unpublished).

– Aiming for highest Q limit, to evaluate the real role of HIPIMS on cavity performance.

Task 12.2 Thin Films

CERN (Cont’d)• Sample study also ongoing at Sheffield to study biased HIPIMS, in order to

implement at CERN in the mid-term:– Delivery of a single cell copper 704 MHz beta 0.65 elliptical cavity for the

study of the angle-of-incidence effect.• Nb3Sn activity not yet started: under discussion (internal production vs

external collaboration).

HZB Berlin• Quadrupole resonator fabricated at Niowave, under surface preparation at

Jlab:– Design studies were presented at SRF13 (PhD student).

• Vertical test stand in production (not covered by EuCARD2, but required for the experiments), delivery Q1 2014.

• Design of a new Helium supply system under way.

Task 12.3 High Gradient NC

CERN• Organizing task 12.3 meeting to be held during the

next CLIC workshop in Feb 2014.

University of Lancaster/STFC/CERN• Damped cavity design now complete, awaiting

fabrication drawings.• Crab cavity construction in UK and at CERN almost

complete.• Developing XBOX pulse compression optimisation

scheme to be used to test crab cavities when available.

• Two PDRA’s appointed, on cavity design and LLRF.

CERN

UK

Task 12.3 High Gradient NC

PSI• All required WFM components delivered at

PSI.• Currently doing lab testing and

characterization:– Results presented at IBIC13.

• Preliminary, non quantitative result: OK in terms of dynamic range and distortion.

• Filled 30% position started Nov 1 at PSI.

CEA/Saclay• Post-doc, candidate selected – start Apr 2014.• Internship, full funding in place, candidate

selection next – expected start Apr 2014.• Phd proposal being prepared for Oct 2014

start.

WFM spectra with beam (insert: simulation)

Task 12.3 High Gradient NC

Uppsalla University• Awaiting funding decision in spring in order to optimize work-plan.

Manchester University• Massively parallel ACE3P simulations ongoing.:

– Initial results encouraging.• CLIC_DDS_A requires attachment of couplers and tuning stubs so CLIC_DDS_A

– Fully bonded single cavity almost complete (confirmed measurements within 5 MHz).

• Further work on the impact of the interleaved wakefields on misalignments.

Task 12.4 SRF HOM Diagnostics

Staffing:• 12.4.1 N. Baboi, L. Shi (Ph.D. Student)• 12.4.2 R.M. Jones, P. Jain (P.D.R.A.)• 12.4.3 U. Van Rienen, T. Flisgen (Ph.D. student)

Overall Status:• Conducted initial simulations of cavity eigenmodes (using CST, HFSS

and custom codes):– Creation of reduced order models of complex and long accelerator

structures.– Computation of RF properties of complex structure using a compact model

(R/Q, external Q‘s of multi-cavity-modes and scattering parameters).– Investigating modes suitable for diagnostic purposes.

• Beam-based measurements in progress at FLASH.

Task 12.4 SRF HOM Diagnostics

• Finalising PRSTAB Paper on, ‘Rigorous Comparison Between Measured and Simulated S-Parameters for FLASH’s Module ACC39’.

• PRSTAB reviewers suggested acceptance after some revisions:– which are anticipated to be finished soon.

Fig: resonator chain with 3.9 GHz cavities in the FLASH modul ACC39. Taken from E. Vogel et al., TUP034 LINAC08, Victoria, BC, Canada, 2008

Task 12.5 RF Photocathodes

• NCBJ– Post deposition

refinement of Pb/Nb surface, evaluating arc deposition parameters.

– Rod Plasma Injector (RPI) process using 1.5 J/cm2 pulses defined a process using 4 pulses of 3 J/cm2

Nb (uncoated)<1µm roughness

Pb (coated)>1µm roughness

Task 12.5 RF Photocathodes

• DESY and HZDR– Preparation of

Pb/Nb photo-cathode plugs for first cavity tests at both DESY and HZDR:

• Jan 14 at DESY.• Apr/May 14 at

HZDR.

DESY

HZDR

Task 12.5 RF Photocathodes

HZB• Test dark current emission from substrates and cathode films under high

electric DC fields:– DC-setup for field emission study.– Current measurement and imaging of field emitter sites.– Device under construction at company.– Set of Diamond Field Emitter Array (DFEA) cathodes from B. Choi, U Vanderbildt.– Start tests early 2014 with substrates and DFEA cathodes.

10 mm

plug

view screen

Courtesy: R. Barday

Cu

Task 12.5 RF Photocathodes

• STFC– Photocathode Surface Analysis and Preparation Installation (SAPI)

completed:• New Kelvin probe for measuring work function successfully commissioned. • Atomic Force Microscope (AFM) and X-ray Photo-electron Spectroscopy

processes (XPS) verified.

Milestone (MS73):

Commissioning Report – In progress and on schedule!0

2000

4000

6000

8000

1000 800 600 400 200 0

O 1s

C 1s

Ag 4p

Ag 3p1/2

Ag 3p3/2

Ag (MNN)

Ag 3d5/2

Ag 3d3/2

Binding Energy (eV)

Cou

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Ag

4

5

6

Wor

k Fu

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0

0.5

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Treatment 1 - Sample 1Treatment 1 - Sample 2Treatment 2Treatment 3

Annealing Temperature (C)P

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nA)

Cu

Summary I

• Task 12.1 Management– Task kick-off meetings occurred and follow-on reviews being prepared.

• Task 12.2 SRF Thin Films– First magnetometer measurements taken at CEA Saclay.– First NbN samples CVD deposited at INP.– Cavities HIPIMS coated at CERN with good results – pushing further!– 704 MHz cavity available at CERN to refine HIPIMS process.– Quadrupole cavity fabricated, surface preparation underway for HZB.

• Task 12.3 High Gradient NC– Fabrication of 2 crab cavities almost complete by UK industry and CERN.– All WFM hardware available and undergoing tests at PSI.– DDS cavity bonded and test results being analysed by UMAN, but look promising.– Massively parallel cavity string simulation model developed by UMAN.– First Milestone (MS74) report expected from PSI by M12 on Front End Design.

Summary II

• Task 12.4 SRF HOM Diagnostics– Complex scattering parameter simulation model developed.– Beam-based HOM measurements on-going on FLASH.

• Task 12.5 RF Photocathodes– Plasma deposition process refined and Pb/Nb photo-cathodes prepared by NCBJ.– Cavity tests expected over the next few weeks at HZDR and DESY.– Field emission system developed and being fabricated by HZB.– Tests with first DAC expected early 2014 @ HZB.– Surface analysis and preparation system completed at STFC.– Milestone (MS73) report being prepared.

• Number of Post-doc and Phd students recruited, but still require:– Task 12.2 Thin Films:

• Post-doc needed @ CEA • Phd student needed @ INP

– Task 12.3 High Gradient NC:• Phd student needed @ CEA (Oct 2014)

Very good progress in all Tasks so far!

WP12 Website

WP12 website can be found here: http://www.cockcroft.ac.uk/events/WP12/