SC RF cavity technology: the possibility of mass scale production, a global review

D.Proch, Thin film Workshop, Legnaro, Oct. 9-12. 2006

SC RF cavity technology: the possibility of mass scale

production, a global review• Remarkable production experience exists for

elliptical type cavities made from solid Niobium ( around 500 units)– Mainly by European companies

• TESLA (20,000) and XFEL (1,000) pushed industrial effort for mass scale production– ILC just starts this effort in USA and Japan

• This talk gives a global overview on the present state of knowledge about mass scale production and related costs


Technical systems: Cavity / module

• Overview on costing activities for mass scale production– European costing method

• Overview industrial methods• General comments on industrialization, risk in

costing– Short report on American costing method– Short report on Asian costing method

• Conclusion


Technical systems: Cavity / Modules

• Elements in cavity / module system– Niobium material– Cavity fabrication

• Input coupler• HOM coupler• Tuning system

– Cavity treatment– Module assembly


European Approach to industrial mass production

• Industrial studies for TESLA (20000 cavities) at 2001

• Appendix to TESLA: XFEL part at 2001– 1000 cavities

• Revised XFEL TDR at 2006 – Corrections for

• Increased material costs• Risk assessment for costs• Inflation

• For ILC: Corrections / modifications to TESLA costs based on findings in XFEL part


TESLA 50020000 cavities

XFEL TDR1000 cavities

ILC Costing18000 cavities

XFEL Appendix1000 cavities

Industrial StudiesEuropean

cost approach for mass scale

production

New industry studies-Module assembly-Coupler fabrication


European cost / mass production evaluation by Industrial Studies

• Analyze production of TTF components– Describe present fabrication process– Determine cost drivers, critical procedures– Define core technology, outsourcing possibility

• Implementation of mass production methods– Evaluate investment of machinery, tooling, roboting– Cost optimize flow of fabrication– Describe layout for “core tech” factory


European cost / mass production evaluation by Industrial Studies, cont.

• Complete planning of new “core tech” factory– Determine costs for buildings, investment, man power, ramp up

& production & ramp down, overhead, consumables, QC,…– Get bits for outsourced parts– Sum up total cost of component fabrication

• NO learning curve assumed (e.g. -10% for doubling the production)• But assumption: stable production after about 50 cavities, couplers,

…– Is verified e.g. by LHC magnet production: assembly time

reached stable (and predicted) level after about 40 magnets

• This cost model is valid because it was developed by experienced companies. Additional studies would require time, money and competent industry.


Components with European Industrial Studies

• Niobium fabrication, done• Cavity fabrication, done• Cavity treatment, done• Module assembly, done

– Revised study is in progress• Input coupler fabrication

– Study in progress

D.Proch, Thin film Workshop, Legnaro, Oct. 9-12. 2006500KW electron beam cold hearth furnace


Comments to cost evaluation• Nb Material (high purity, RRR 300)

– No shortage of raw Nb material (40.000 tons annual production, ILC needs around 500 tons

– But limited number of high purity melting facilities• Today there are 4 qualified companies, but only one is capable of

producing full yield– Marginal savings in mass production (from industrial study)

• Size of melting furnace is limited• But some saving can be realized by

– Disc rather than rectangular sheet (scrap can be recovered)– Other material produced ready for fabrication, e.g. flange material

• But: Latest developments in large/single crystal cavities promise cost reductions

• The result is robust costing


High purity Niobium production

49%

21%

17%

3% 2%1% 7%

Melting Raw material Rolling Firing Forging Chemistry scrap


Niobium RRR 300

9 cells: compromise between filling factor and trapped modes

1.3 GHz

Deepdrawn from sheets Welding with electron beamOperating temperature 2K

•TESLA 9-cell Niobium Cavity

Proposal is based on proven available technology


Cavity production


Comments to cost evaluation• Cavity fabrication

– Experienced companies in Europe• More than 500 type TESLA cavities have been

fabricated so far• Fabrication process is well understood and stable• Cost drivers: EB welding process (50% total cost)

– Cure: reduced pump down time by multiple vacuum chambers welder

– Cure: mass production welding tooling• Cost saving in large scale production is well

understood

• The result is robust costing


Reduction of fabrication cost

• 3 vacuum chamber welding machine:– Pump down and cool down in separate

chamber– Welding in middle chamber

• Tooling for welding many parts in one cycle

• Outsource machining of parts


Production facility


Cavity Prototype production cost

35%

49%

4%6% 3% 2% 1%

Machining

Welding

QA

Chemistry

Administration

Consumables

Storage

Cavity mass production cost breakdown

77%

10%4% 4% 2%1%2%

Machining

Welding

QA

Chemistry

Administration

Consumables

Storrage


DESY Electro-polishing machine


Comments to cost evaluation• Cavity treatment

– Standard treatment is EP, 130°C bake, high pressure water cleaning, clean-room assembly

– Technology transfer to industry just started• Cost evaluation has some uncertainty• Industrial involvement is needed to develop

procedures which produce higher performance yield

• Costing result has risk: – Uncertainty in cavity treatment


Baseline design


Comments to cost evaluation

• Input coupler– Cost is high, comparable with cavity fabrication !!– Present industrial fabrication around 80 couplers.

Industry identified cost savings which were included, e.g. standardized tube sizes

– Ongoing industrial study (XFEL) on mass production will deliver a reliable cost number

• Present costing has some risk– But ongoing industrial study will deliver robust costing


For the XFEL power couplers, industrialization studies will be performed through “Definition contracts” :

• Essentially intellectual work (in dialog between the industry and our Lab) : Define all manufacturing processes (analysis and validation models) Risk analysis (process, logistics) Determine cost in series and justify

• Produce 2 prototypes (to be tested at LAL – Orsay)

Particularities• 3 contracts will be awarded on the same subject: « Industrial studies »• 2 teams will be selected after final evaluation• contracts for manufacturing 2 series of 500 XFEL couplers will be awarded without a new call for tenders• the 2 contracts may be awarded to a single company


Cavity Preparation; String and Module Assembly



Cryomodule Assembly

Clean room assembly Assembly outside cleanroom

the study shall cover clean room assembly and the assembly outside cleanroom

Startpoint: string assembly in cleanroom

(all parts are tested and ready for assembly)


Scope

The present cryomodule assembly procedures and some aspects of the present design shall be analyzed and questioned with respect to the most cost effective serial production.

The key aspects of the study are as follows:1.2.1 Define the assembly procedure1.2.1 Analyze cost-reduction and production efficiency measures1.2.3 Analyze performance improvement measures1.2.4 Supply a cost estimate for the module production

A substantial part of the IS shall be the presence of CONTRACTOR’s experts during the assembly of two prototype cryomodules at DESY.

Industrial XFEL-cryomodule design and assembly study

Supported by the EUROFEL design studySupported by the EUROFEL design study


American costing method

• There is fabrication experience in some laboratories from earlier projects

• American industry was only involved to minor extend

• A new industrial study on cavity mass production is on the way

• Costing is based on prototype fabrication and learning curve for mass production


Asian costing method• In Japanese culture industry has been

involved in early stage in accelerator projects, e.g. Tristan, KEKB

• Industry is a major driver in EP (electro polishing) and coupler development

• In house (KEK) cryo-module development is under way

• Costing is a combination of industrial involvement and learning curve


Summary & Conclusion: Mass scale production of SC

accelerator systems • Industrial expertise exists in SC cavity and

for most of the SC sub-systems ( auxiliaries)

• European Industry has a world leading position– Japanese industry has specialized expertise– US industry just starts in SC technology

• SC cavity technology is based on solid Nb material


Perspectives of thin film technology

• Immediate benefit– Thin Nb film is much cheaper than bulk Nb sheet: A

must for large cavities ( at low frequencies)• Short term goal

– Thin Nb films promise enhanced intrinsic properties (high Q value, no need for magnetic shielding,…

• Long term goal– Use of new SC compounds with higher critical fields

and/or at higher temperatures


Strategy

Lets combine the enhanced thin film properties

with the industrial experties in bulk Nb for the next generation of

SC cavity mass production technology



Design of the new slow & fast cold tuner

CARE JRA-SRF Partner Cooperation between :TUL (Polen), CNRS Orsay, CEA and INFN Mi

Documents

SC RF cavity technology: the possibility of mass scale production, a global review