1. 19-10-2017 Update on test results MBHDP102 Re-discussion of test program
By Gerard Willering, TE-MSC-TF
With inputs of Franco Mangiarotti, Jerome Feuvrier, Vincent Desbiolles, Christian Loffler, Emelie Nilsson

2. Powering history Day 1 Day 3 Day 2 Day 4 Day 5 11kA splice
50 A/s quench
Quench 1
50A/s
precycle
Day 1
8 kA Splice
1 kA EE
3 kA QH
Day 3
50 A/s precycle
Loadline MM
1 hour at 11.3 kA
10 A/s ramp to quench
Quench 2
100 A/s quench
Quench 3
Day 2
Day 4
Machine cycle MM
Machine cycle MM
RR study
200 A/s
QH firing at 6 kA
No EE
Day 5

3. Quenches 3 quenches Identical location
No sign of any mechanical movement
Ramp rate dependency behavior quite like SP105 midplane limitation, but at lower current level.

4. Training quenches
No quenches in pole turns up to 11.4 kA following re-collaring
# quenches to that current level:
Coil 109: 4
Coil 112: 3
Coil 114: 2
Coil 115: 2

5. Quench signatures
Conclusion
Every quench including at 50 and 200 A/s originated in the same spot.

6. Quench localisation Slope – 40 m/s Splice coil 109 inner layer
Delay of 4-6 ms
Splice coil 109 inner layer
Quench location of all quenches Some 240 ± 100 mm from voltage tap 109II

7. Quench Antennas
The two main Quench Antenna are moving at about the same time.
We are investigating if there is physics behind or if there is another issue with the data.

8. Resistance measurements during ramp
1 hour stable at 11.3 kA
Followed by ramp at 1 A/s to quench at kA
Stable voltage in the segment and splice at the plateau!
Raw data
Superconducting segment (green curve) shows resistance growth that looks like a power-law behavior.
Flux jumps
I added a power law to the plot to show its resemblance (black curve), but without any intention to publish it like this, just to grab the idea that we are looking at some sort of SC to normal transition.
Inductive voltage subtracted
0.3 nOhm slope hardly visible

9. Advanced measurements with accelerometers and quench antenna
Ramp following a quench
Ramp following another cycle
Low activity from 4-8 kA
High activity from 4-8 kA
The spikes that are seen with quench antenna are clearly of mechanical origin, showing damped oscilation.

10. Mechanical measurements
Unloading from about 5 to 8 kA measured on the collars
After a quench the collared coils are in a different strain state than after a cycle. This has been seen for all models.
Mechanical data gathering and analysis by
Philippe Grosclaude, Emelie Nilsson and Christian Löffler

11. Magnetic measurements
Ongoing. No obvious anomalie, deeper investigation needed.

12. Finalize magnetic measurements (Thursday – Friday) at 1.9 K
To do list
Finalize magnetic measurements (Thursday – Friday) at 1.9 K
During MM measure resistive voltage on all mid plane turns to exclude or confirm similar patterns in other midplane turns.
Perform temperature dependent quenches from 1.9 K to 4.3 K (3 days)
Possibly delay slightly (10-20 ms) the quench heaters to reduces energy deposition in the He bath (we will stay well below 15 MIIts).
At 4.3 K perform at least one RR study at 200 A/s for comparison
Keep monitoring the resistances in the various segments.
Improve Quench Antenna measurement for localization by adding the magnetic measurement shaft in the quenching aperture.
Perform Magnetic measurements at 4.3 K (1 day)
Perform Protection studies (reduced program) including CLIQ at 1.9 K (2-3 days)
Limited program: No spot heater, maximum 11 kA.
Test program for about 7-8 days, warmup can start around 31st of October.
- Thermal cycle: Any interest?

13. Other ideas???
Ideas for other cold test??
Ideas for warm test??
Ideas for investigation of the coil after warmup??