1. Material for Large Scale Cavity Production
W. Singer, X. Singer, DESY
B. Spaniol, W.C. Heraeus
Presented by Waldemar Singer

2. Material main issues
First experiences with cavity material for XFEL
- Qualification of Nb suppliers for XFEL
- Current status of the material contract for XFEL cavity
Where is the bottle neck for large scale material production?
Remarks

3. Qualification of Nb suppliers for XFEL
5 qualified companies
About t. of high purity niobium are required
Three qualified for FLASH Nb suppliers: Wah Chang (USA), Tokyo Denkai (Japan), HERAEUS (Germany).
Several companies anticipated to be qualified for XFEL (CBMM, GIREDMET, Plansee, OTIC Ningxia)
Three steps of qualification for XFEL have been determined:
Step 1. Material testing (RRR, Microstructure, Eddy current scanning, Tensile test, Hardness, Impurity content).
Step 2. Single cell cavity fabrication at DESY, treatment and RF tests at DESY.
Step.3. Nine cell cavity fabrication at Industry, treatment at DESY and RF tests.
Only two companies Plansee (Austria) and Ningxia OTIC (China) successfully passed all three steps. 5 companies qualified for XFEL currently

4. >15 000 pieces of semifinished products (sheets, tubes, etc.)
Status: Material for XFEL Cavities
Material for 680 Cavities will be provided by DESY
to RI and E.ZANON
Mid 2011 – Beginning 2013
Contracted January 31st, 2011 to companies:
W.C. Heraeus,
Tokyo Denkai,
OTIC Ningxia,
SE Plansee
> pieces of semifinished products (sheets, tubes, etc.)

5. Current status of contract: Material procurement
DESY has taken over the responsibility for
incoming QC
testing for required parameter (RRR, HV etc.)
scanning of sheets
documentation (guarantee of traceability for pressure bearing parts)
definition of numbering system and marking
delivery to company
One of the aspects of the QC is the eddy current scanning. New equipment for eddy current scanning of XFEL niobium at DESY

6. Independent from company QC and acceptance on company site are indispensable
In House (DESY)
RRR
Scanning - Apparatus
Interstitial impurity analysis (H,N,O, C)
Metallic impurities analysis (another RM, Fe, Ni etc.)
Metallography
Tensile test
Hardness, HV
Surface roughness
Thermal conductivity
Outsource
NAA Neutron Activation Analysis
Radiation Fluorescence Analysis
SEM, EDX
SIMS, XPS, AUGER
X-ray radiography
Neutron radiography
Texture analysis
Bulging test
Scheme of QC of Nb sheets

7. Material PED (Pressure Equipment Directive) Activities
The notified body (TUEV NORD) will supervise the material procurement
PED Activities
Qualification of cavity material Nb40, Nb300, NbTi, Ti1 and Ti2 (creation the particular material appraisal (PMA)).
W.C.Heraeus and SE Plansee have a current PED certification
Certification of QM system at the companies Tokyo Denkai and Ningxia OTIC by TUEV NORD. Audit of TUEV is foreseen for March 2011
Supervising of the semi finished material products procurement (traceability, marking, 3.1 test certificates etc.)

8. Remarks to procurement of material for XFEL cavities
1. DESY will purchase the material and ship to RI and E. Zanon
This is reasonable from the commercial point of view, but less reasonable from the technical point of view.
Semi finished products can be more optimally adopted to requirements of the cavity producers, if the cavity producers would order the material themselves
2. Without qualification of new suppliers (Ningxia OTIC, Plansee) we would not have enough material for XFEL cavities (ca. 15 t in 2 years).

9. Nb sheet production process
Where is the bottle neck for large scale material production?
H.Umezawa (Tokyo Denkai)
Three bottle necks
Nb raw material with low content of Ta (facilities for liquid - liquid extraction, Nb ore with low Ta content)
Melting capacities
Nb sheet production process

10. TESLA Industrial Study 2002
„Production of Niobium with the Quality RRR300“
K.-H. Wahl, B. Spaniol
Main costs: raw material (21%), EB melting (49%), sheet rolling (17%)

11. Comparison of the TESLA Study and the actual situation is showing strong deviations:
- Costs of row material increased currently by factor 3
The melting costs in the Tesla Study are high (investment in new EB furnaces)
- The rolling costs in the study seems to be too low

12. Possible Solution
TESLA Study proposal as a safety solution was to build 5 new EB facilities. In 5 years the material for TESLA cavities can be melted
Each Nb producer has a main business (core business). The main business is not our high purity Nb (Tokyo Denkai - Ta, Heraeus - Nb1%Zr, Wah Chang - NbTi etc.)
Otherwise the availability of Nb for ILC will depend on current situation on the market and presence of another big projects (like ITER now)
Or the time of delivery has to be significantly increased

13. Alternatives: Large Grain LG Cavity LG ingot and disc fabrication
Cutting of the large grain Ingots by wire sawing at W.C.Heraeus
Development of LG disc production was done within the framework of the XFEL R&D program of DESY and the W. C. HERAEUS.

14. Alternatives: Large Grain LG Cavity
XFEL Requirement
11nine-cell DESY cavities from LG Nb of Fa. HERAEUS are fabricated at Fa. RI Treatment: 100µm BCP, 800°C 2h, 20µm BCP, HPR and 125°C, 50 h baking. 100 µm BCP done at Fa. RI.

15. Alternatives: Large Grain LG Cavity LG ingot and disc fabrication
Tokyo Denkai

16. 9 - cell hydroformed cavities
Z145
Z163
Z164
9-cell cavity from hydroformed at DESY units completed at JLAB

17. Thank you