1. LN2 Thermal cycling of 11T short coil #107
Jan Petrik, Arnaud Foussat - TE/MS-LMF
Laetitia Dufay-Chanat, Sebastien Prunet, Johan Bremer - TE/CRG-CI
EDMS:

2. Introduction Goal is to evaluate effect of temperature cycling on
Impregnated Quench heater insulation to coil resistance
First contact with TE/CRG-CI on 11th December
First cycle on 5th February
10 cycles by 15th April
24h cool-down cycle
One cycle per week, limited by warm up power
Controlled ΔT during magnet cool-down
50K Average
78K Maximum
Insulation resistance measurement – 660V, 2mins

3. Test Setup
A 200 mm diameter cryostat with a cartridge heater is connected to 600 l Nitrogen dewar and to the “swimming pool” in which the magnet is placed;
During the cool down, the temperature of the gas entering the set-up is regulated to a temperature 100 K lower then the warmest point measured in the magnet set-up;
During the warm-up, this gas is regulated to a temperature 100 K colder then the coldest point measured in the magnet set-up;

4. Temperature Profile

5. -> humidity build up
Results
Different temperature
(around 0C)
Out of LN2, different warm up procedure
-> humidity build up
Other tests are for quality control. Results noted into individual excel files, checked and then stored in EDMS
Jan Petrik, 15/05/2019 5

6. Results
Other tests are for quality control. Results noted into individual excel files, checked and then stored in EDMS
Jan Petrik, 15/05/2019 6

7. Results
Other tests are for quality control. Results noted into individual excel files, checked and then stored in EDMS
Jan Petrik, 15/05/2019 7

8. Conclusions
Humidity and temperature influenced a lot the QH insulation resistance.
Is this influence by humidity developed through insulation cracks?
Flush with room temperature nitrogen helps
#121R has shown biggest variance during the testing due of humidity.
No increase of leakage current observed during the thermal cycle campaign
break down voltage was not tested
Jan Petrik, 15/05/2019