FNAL/ANL/UC SRF R&D Collaborations

Lance Cooley – new SRF Materials Group Leader at FNAL

A Regional “Center of Excellence” effectively started through the efforts of Pierre Bauer and Claire Antoine

Research topics concluding Oct-Dec 07– Grain-boundary properties – Polyanskii (ASC-FSU*)

– Local nano-chemistry by 3D Atom probe – Seidman (NU)

– Thermal conductivity and Kapitza resistance – MSU

– Fundamentals of SC, theory – A Gurevich (ASC-FSU)*

Topics proposed recently for SRF R&D that are ripe for seeding– Mapping the superconducting gap on Nb surfaces - M Iavarone (ANL)

– Atomic layer deposition applied to cavity surfaces – M Pellin (ANL)

– Multilayer SRF structures – M Pellin (ANL)

Other topics that make sense to initiate – Nanometer scale chemical kinetics and morphology of niobium oxidation

– S Sibener (UC)

– Magnetometry of Nb crystals, welds, etc. – Welp (ANL)

– SRF theory – Koshelev (ANL)

*formerly U Wisconsin Applied Superconductivity Center

Guiding vision

Increase the vertical span of R&D to utilize basic understanding, thereby accelerating progress and producing breakthroughs sooner– Orbach: SRF is an enabling technology. US leadership in SRF

science strengthens our ability to put ILC on US soil.– Marx panel: Breakthroughs produced by the “LTSW consortium” far

outweighed the AARD investment for high-field magnets, so use it as a model

– Develop understanding that underlies “basic” work at FNAL– Seek understanding that further enables niobium– End users and basic researchers need to speak common language

• Basic researchers work toward needs identified by end users • End users gain access to knowledge first hand and prior to

publication

Guiding vision

Involve academia and BES labs– Allow academic freedom within the context defined by end users

• Undertake “measurement services” separately• $100k/yr is threshold for academic value

– Fill the researcher pipeline via student projects, Ph.D. theses– Make SRF materials available to basic researchers– Encourage round-robin and joint experiments among research groups

using common samples– Take advantage of complex probes, advanced facilities, and (most

importantly) expertise outside labs• An experienced researcher is worth more than the instrument

– Possibility of testing hypotheses on “real” cavities

Guiding vision

Build long-term excellence– Find pathways toward future breakthroughs outside of present ILC

materials• Basic understanding of surface superconductivity• Integration of surface science with SRF• Breaking the “niobium monopoly”

Tie-in to ILC

FNAL is building a strong single cavity R&D program, which will work in conjunction with 9-cell pre-production, test, QA, and simulation

Single-cell program is the entry point for basic understanding to the ILC knowledge chain

ILC EDR must continue to consider “alternates”, which provide pathway for breakthroughs to positively affect cost and performance

There are many key scientific questions

Practical Are present niobium specs

adequate? What are the differences in raw

sheets that matter? How deep does surface damage

penetrate? Are present etching recipes sufficient?

How are cold mechanical properties affected by processing (etching, annealing, welding…)

What is it about sulfur particulates that make them difficult to remove (after EP)?

How can we prevent particle re-contamination and field emission ?

Fundamental How are oxygen & oxides

arranged and what happens to them during/after etching? Baking? Annealing?

How does surface chemistry affect superconductivity? RF superconductivity?

What new information can new surface probes provide?

Are grain boundaries bad? If so, why? Are there mitigation strategies?

Can multilayer coatings produce RF fields higher (and lower losses) than that possible with niobium?

Talks by ANL and UC Investigators

Proposal: SRF Center of Excellence

Characteristics of regional collaboration are similar to those of NSF or DOE Center of Excellence

Proposal: leverage regional activities into sustained national effort of ~$2M/yr scale– Target: combined NSF (Goldberg) and HEP (Debenham)– Charge: Sustain progress on key scientific issues via

• Curiosity-driven research within end-use context• Collaborative research with labs• Interactions with industry and SBIR

– Management:• Annual or semi-annual workshop will be important for reporting• Executive committee shall (re)identify key scientific issues based

on needs and progress

IIT

MSU

FSU

TJNAF

ANL

FNAL

DOE NSF

UC

N’western

Exe

c. C

omm

ittee

Network interchange of ideas and samples

Cornell

Industry

SBIR