1. Infusion R&D at DESY TTC Meeting at TRIUMF – 06.02.2019
M. Wenskat – on behalf of the SRF Team

2. Sixth and Seventh Infusion Run
With Nitrogen – 120°C

3. 1DE10 Field emission? No FE during VT observed – QvE looks like FE
3 X-Ray Films & retest

4. Eighth Infusion Run With Nitrogen – 160°C
2nd 160°C infused Cavity (1DE7) to be tested after clean room maintenance

5. Infusion @ FNAL 1DE3 FG Baseline @ DESY
1st FNAL failed due to leak
Re-set & FNAL
Accidentally low-T baked
120°C Infusion successful
Send to DESY
1DE20 LG
„Vivid History“
Re-set & FNAL
Low-T baked
120°C Infusion successful
Send to DESY

6. 1DE3

7. 1DE3
FE in FNAL test – infusion „partially“ successfull

8. 1DE3

9. 1DE3

10. 1DE3
Next steps:
different cooldowns

11. 1DE3 Different Cooldowns
FNAL - Measured on another cavity!
dT/dt for RT → 20K higher for fast cooldown compared to normal cooldown
dT/dt for 20K → 2K slower for fast cooldown compared to normal cooldown

12. 1DE3
T16: 3.7 / 4nOhm
T17:<4nOhm

13. 1DE20
Rres decreased by 0.9nΩ between t2 and t3 (obtained with Qvs.T) – probable RRR sensors
Still not enough to explain increase in Q0 :
3->2.1
Test 2: Q(2K) = 2.7 ·1010 (10 nΩ) ; Q(1.8K) = 4.5 ·1010 (6 nΩ) Test 3: Q(2K) = 3.4 ·1010 (8 nΩ); Q(1.8K) = 5.9·1010 (4.6 nΩ) (normal cooldown)

14. 1DE20
Deconvolution

15. Summary Infusion R&D on-going
Furnace R&D (Hardware improvements, Process variations)
New caps are ready for next run (“flange with a defined leak”)
“Fresh” 160°C infused cavity next
Work in progress to understand test results
Compare cooldown procedures
Improve diagnostics (H- and T-sensors)

16. Thanks for Listening
Thanks to the complete DESY and Nanolab SRF team, I gave this talk on their behalf
Only collaboration with many partners allows for complex R&D work

17. Back Up

18. 1DE27 - Samples Inside Nb Box in furnace 120°C Infusion 160°C Infusion
Note: We did not put a sample from the first infusion run into the second infusion run

19. Sample Surface = Cavity Surface?
Origin of deterioration?

20. Magnetic Fields during Fast Cooldown
MF1
MF2
MF3
ΔT=3K
Bsc/Bnc = 1.38