Superconducting coils for damage studies
This page was created as source of information about small racetrack superconducting coils created for damage study foreseen in October 2022.
1. Measuring the gap size
The gap, where wire will be placed was designed to have a width of 4.9 mm (±0.1 mm). To check this, twelve different pieces were measured with micrometer (precision ±0.0001 mm).
It could be seen from the attached table that, the actual size of the gap is in fact more than 0.02 mm bigger.
2. Labeling the coils
To distinguish between coils, they were labeled with numbers between 0-29. The label is always on side where the winding is started. Following table specifies the coils.
Coil's number |
Winding material |
Tension |
Additional information |
Washers inserted |
Current status |
G10 holder on |
Location |
0 |
NbTi |
8 kg |
Used for test-winding with copper |
Yes |
Qualified |
no |
UniGe |
1 |
NbTi |
8 kg |
|
Yes |
Qualified |
no |
UniGe |
2 |
NbTi |
8 kg |
|
Yes |
Qualified |
no |
UniGe |
3 |
NbTi |
8 kg |
|
Yes |
Winded |
no |
UniGe |
4 |
NbTi |
8 kg |
On terminal the insulation is broken |
Yes |
Winded |
X |
X |
5 |
NbTi |
8 kg |
|
Yes |
Winded |
no |
UniGe |
6 |
NbTi |
8 kg |
|
Yes |
Winded |
no |
UniGe |
7 |
NbTi |
8 kg |
|
Yes |
Winded |
no |
UniGe |
8 |
NbTi |
8 kg |
|
Yes |
Winded |
no |
UniGe |
9 |
NbTi |
8 kg |
|
Yes |
Winded |
no |
UniGe |
10 |
NbTi |
8 kg |
|
Yes |
Qualified |
no |
UniGe |
11 |
NbTi |
8 kg |
|
Yes |
Winded |
no |
UniGe |
12 |
NbTi |
8 kg |
|
Yes |
Winded |
no |
UniGe |
13 |
Nb3Sn |
5 kg |
|
Yes |
Unreacted |
no |
office |
14 |
NbTi |
8 kg |
|
Yes |
Winded |
yes |
UniGe |
15 |
NbTi |
8 kg |
|
Yes |
Winded |
yes |
UniGe |
16 |
Nb3Sn |
5 kg |
Test soldering 1 - high temp tape added |
Yes |
Reacted |
yes |
Polymer lab |
17 |
Nb3Sn |
5 kg |
1B soldering, A miss - high temp tape added |
Yes |
Qualified |
yes |
UniGe |
18 |
Nb3Sn |
5 kg |
1B soldering, impossible to deatach from holder piece |
|
Destroied |
no |
office |
19 |
Nb3Sn |
5 kg |
1C soldering, careless handling, B;C miss - high temp tape added |
Yes |
Reacted |
yes |
Polymer lab |
20 |
Nb3Sn |
5 kg |
1C soldering - high temp tape added |
Yes |
Reacted |
yes |
Polymer lab |
21 |
Nb3Sn |
5 kg |
1C soldering - high temp tape added |
Yes |
Reacted |
yes |
Polymer lab |
22 |
Nb3Sn |
5 kg |
1B soldering - high temp tape added |
Yes |
Reacted |
yes |
Polymer lab |
23 |
Nb3Sn |
5 kg |
1B soldering, C miss - high temp tape added |
Yes |
Reacted |
yes |
Polymer lab |
24 |
Nb3Sn |
5 kg |
1B soldering |
Yes |
Reacted |
X |
Polymer lab |
25 |
Nb3Sn |
5 kg |
|
Yes |
Unreacted |
X |
Daniel's office |
26 |
Nb3Sn |
5 kg |
1C soldering - high temp tape added |
Yes |
Reacted |
yes |
Polymer lab |
27 |
Nb3Sn |
5 kg |
1B soldering - high temp tape added |
Yes |
Reacted |
yes |
Polymer lab |
28 |
Nb3Sn |
5 kg |
Test soldering 1, Dismount 1, Polish 1, drilled x 2 second time into copper |
Yes |
Impregnated |
yes |
UniGe |
29 |
Nb3Sn |
5 kg |
1C soldering |
Yes |
Reacted |
yes |
Polymer lab |
Test soldering1: coil was in oven @ 230C for 15 minutes, but apparently it was not enoght. After that the soldering paste was scratched away. After that another soldering was performed. Coil stayed in over for 15 minutes at 270C. For soldering a solder with Ag was used.
1B soldering:
- Surface was cleaned with the alcohol
- Small portion of soldering paste(Sn63Pb37) was applied just on strand
- Coils were inserted into furnace for 10 minutes at 250C
- It was not enough for 6 coils so another 20 minutes at 260C
- Solder soaked in the groves, so small amount of solder was added where needed
- Coils were taken out and it was cooling down
- Coils were preheted again to 150C for 10 minutes
- Voltage taps were soldered to the coil
1C soldering:
- Surface was cleaned with the alcohol
- Through holders, which hold SC wire one pair of voltage taps was put in
- Small portion of soldering paste(Sn63Pb37) was applied just on strand
- Coils were inserted into furnace for 20 minutes at 260C
- All coils were taken out
- Second pair of voltage taps was soldered on hot coils (once soldering paste deliquified)
- On coils [19,20,29] during dismounting one voltage tap felt of (tap sticked to overlaying SC strand), so additional soldering of these taps was performed (preheat 10 minutes to 180C then solder)
Dismount 1: dismounting SS holder piece was done by putting a sharp knife in the interface between SS and Cu. By hammer two halfmoons was deatachted.
Polish 1: A small layer of resin after impregnation, which had to be taken out using a sharp knife and brushing mashine. The holes for screwing coil on VTI probe was full of epoxy, so had to be drilled out again.
17/08: new labes were created on last batch of 10
Nb3Sn coils. From #30 to #40. 38, 39 one tap lost => soldered on side. #40 all taps lost => one pair solderd on side.
(34 new is 29 old)
STATUS OF COILS ON 14TH OCTOBER:
Coil's number |
Winding material |
Tension |
Additional information |
Washers inserted |
Current status |
Location |
0 |
NbTi |
8 kg |
Used for test-winding with copper |
Yes |
Qualified |
Cryostat |
1 |
NbTi |
8 kg |
|
Yes |
Qualified |
Cryostat |
2 |
NbTi |
8 kg |
|
Yes |
Qualified |
C ryostat |
3 |
NbTi |
8 kg |
|
Yes |
Winded |
office |
4 |
NbTi |
8 kg |
On terminal the insulation is broken |
Yes |
Winded |
office |
5 |
NbTi |
8 kg |
|
Yes |
Winded |
|
6 |
NbTi |
8 kg |
|
Yes |
Winded |
Cryostat |
7 |
NbTi |
8 kg |
|
Yes |
Winded |
Cryostat |
8 |
NbTi |
8 kg |
|
Yes |
Winded |
|
9 |
NbTi |
8 kg |
|
Yes |
Winded |
office |
10 |
NbTi |
8 kg |
|
Yes |
Cryostat |
Cryostat |
11 |
NbTi |
8 kg |
|
Yes |
Winded |
office |
12 |
NbTi |
8 kg |
|
Yes |
Winded |
|
14 |
NbTi |
8 kg |
|
Yes |
Winded |
Cryostat |
15 |
NbTi |
8 kg |
|
Yes |
Qualified |
Cryostat |
Coil's number |
Winding material |
Tension |
Additional information |
Washers inserted |
Current status |
G10 holder on |
Location |
13 |
Nb3Sn |
5 kg |
|
Yes |
Unreacted |
no |
office |
17 |
Nb3Sn |
5 kg |
1B soldering, A miss - high temp tape added, first qualified 15th July |
Yes |
Qualified |
yes |
office |
18 |
Nb3Sn |
5 kg |
1B soldering, impossible to deatach from holder piece |
Yes |
Destroied |
no |
office |
25 |
Nb3Sn |
5 kg |
|
Yes |
Unreacted |
X |
Daniel's office ? |
28 |
Nb3Sn |
5 kg |
Test soldering 1, Dismount 1, Polish 1, drilled x 2 second time into copper, second qualified on 25th July |
Yes |
Qualified |
yes |
UniGe |
Coil's number |
Winding material |
Tension |
Additional information |
Washers inserted |
Current status |
Location |
30 |
Nb3Sn |
5 kg |
|
Yes |
Qualified |
Cryostat |
31 |
Nb3Sn |
5 kg |
|
Yes |
Impregnated |
office |
32 |
Nb3Sn |
5 kg |
|
Yes |
Qualified |
C ryostat |
33 |
Nb3Sn |
5 kg |
|
Yes |
Qualified |
Cryostat |
34 |
Nb3Sn |
5 kg |
|
Yes |
Qualified |
Cryostat |
35 |
Nb3Sn |
5 kg |
|
Yes |
Qualified |
Cryostat |
36 |
Nb3Sn |
5 kg |
|
Yes |
Qualified |
Cryostat |
37 |
Nb3Sn |
5 kg |
|
Yes |
Qualified |
Cryostat |
38 |
Nb3Sn |
5 kg |
|
Yes |
Qualified |
Cryostat |
39 |
Nb3Sn |
5 kg |
|
Yes |
Impregnated |
office |
40 |
Nb3Sn |
5 kg |
|
Yes |
Impregnated |
office |