1. FKPPL and FJPPL Joint Workshop
A_RD_11:
Development and Validation of Input Power Coupler for Superconducting Linacs
Seoul, May 18th 2016
How to edit the title slide
Upper area: Title of your talk, max. 2 rows of the defined size (55 pt)
Lower area (subtitle): Conference/meeting/workshop, location, date, your name and affiliation, max. 4 rows of the defined size (32 pt)
Change the partner logos or add others in the last row.
Eiji KAKO, Taro KONOMI, Toshio SHISHIDO- KEK
Hassan JENHANI, Stéphane BERRY, Christian ARCAMBAL, Guillaume DEVANZ - IRFU/CEA
Walid KAABI, Hayg GULER- LAL/CNRS

2. Introduction:

3. Brazed warm and cold parts with internal surface copper coated
Introduction:
From single parts
Brazed warm and cold parts with internal surface copper coated
Two different ways to proceed:
Process 1: To copper coat the single parts before brazing:
Better copper quality & distribution control
Easy setup
Brazing thermal cycle impacts the RRR parameter
Process 2: To braze the single parts then copper coat the entire set:
Complicate copper coating process setup
much effort needed to master the process: good Cu distribution + defect free surface
No impact on the RRR parameter

4. Investigation on Process 1: Copper coating before brazing

5. Copper coating before brazing: Cross-section (thickness) measurements
E. KAKO
Cu-plating 14 mm
Cu-plating 18 mm
Cu-plating 3 mm
Cu-plating 19 mm
Cu-plating 20 mm
Cu-plating 31 mm

6. Copper coating before brazing: RRR measurements
Results (4.2K – 300K)
E. KAKO
Cu-plating +
SUS
Cu-plating samples
Only SUS
RRR measurement system
RRR = r (300K) / r (4.2K)

7. Copper coating before brazing: RRR values before/after heat treatment at 800oC
E. KAKO
Hydrogen Furnace
Vacuum Furnace
Before HT
Before HT
After HT
After HT
Thickness of Cu-plating [mm]
Thickness of Cu-plating [mm]
Remarkable degradation of RRR was observed after HT.

8. Copper coating before brazing: Composition analysis of Cu-Plating
E. KAKO
Cu plating + Au strike
Cu plating + Ni strike

9. Copper coating before brazing: Composition analysis of Cu-Plating
Cu 12 mm
Cu 16 mm
Cu 29 mm
E. KAKO Cu
26mm Cu
13mm Cu
9mm Cu
1mm Ni Cu
13mm Cu
9mm Cu
1mm Cu
9mm Cu
1mm Ni Ni
Thickness of Cu-plating [mm]

10. Investigation on Process 2: Copper coating after brazing

11. Copper coating after brazing: Thickness distribution measurements
Copper thickness distribution in the cold conductor (specif. 10μm ± 20% in the cylindrical section & 10μm ± 30% in the bellow relaxed to 10μm ± 50% ):

12. Copper coating after brazing: RRR measurements
RRR measurements (Specif. 10<RRR<80)

13. Copper coating after brazing: Composition analysis of Cu-Plating-IFMIF coupler
RRR before 400°C/2h treatment = RRR after 400°C/2h treatment = 32
H. JENHANI

14. Copper coating after brazing: Visual inspection & defects detection
Example of copper coating defects:
 Setting qualitative and quantitative acceptation criteria: classification by defect type, dimension et number. Agreement about corrective actions and validation tests.
Copper peel off
Blister
X 20
Pitting
X 30
X 22
Circular spots
Copper particle

15. Copper coating after brazing: Investigations on coupler finishing treatment
Example of copper surface anomalies and their cure experimented on couplers or samples:
Copper wool burnishing to remove brazing roll located on the antenna tip at the interface of copper bulk material and copper plating material.
Scratches are eliminated are burnishing or bead blasting
The lack of the copper is tolerated in particular situations
Stains generated by light oxidation can be tolerated
Large stains :
Mechanical used methods : burnishing or bead blasting
Chemical used methods:
US bath + Tickopur R33 detergent
Sulfamic acid for small oxidation stains (if needed)
RBS T310 detergent for important oxidation
Dark color on the air side of the ceramic can be sandblasted
Others: Compare with the Prototype Power Couplers
H. JENHANI

16. SS copper plated sample
Copper coating after brazing: Investigations on coupler finishing treatment
Ceramic wiping applied on copper plated sample:
H. JENHANI
Ceramic wool wiped region
SS copper plated sample
Ra=1.04
No Ceramic Wiping
Ra=0.42
Light Ceramic Wiping
More CeramicWiping
Ra=0.39
Surface investigation using Confocal Microscopy (KEYENCE VK-X200):
Observations with Microscope:
No contamination of the surface with the ceramic wool
Particle counting in ISO5 clean room:
Cleaning with UP water/US bath/detergent, then particle counting  The counted particles number decrease down to zero
 No cleaning issues due to the ceramic wool wiping

17. Conclusions:
Efficient Sharing of investigations help to optimize each process to make it more mastered and thus mature for mass production.
Working on improving the two process might lead to a decrease of cost of power couplers.
Knowing processes weak points helps a lot to avoid extra-work and reduce the rejection rate during the manufacturing phase (saving time and money for industrial).
Many other items are still to be investigated (conditioning procedure, cleaning and clean room assembly procedure optimization, decreasing the coupler fabrication cost).