Leak and pressure tests in magnets production chain

1. Leak and pressure tests in magnets production chain

Galimov A.R.
JINR-GSI meeting, 2018-12-02

2. Applied helium leak test methods

A) Enclosure test (integral leak detection);
B) Spray technique (local leak detection);
С) Enclosure test (integral leak detection);
D) Sniffer technique (local leak detection)
E) Bubble test
Leak detectors:
ASM310
ASM380
HLT575
ASM340
Maximum sensitive:
5×10-13 Пам3/с (5×10-12 mbar•l/с)

3. Enclosure test

Isolators
Tubes
Parts of magnets (sometimes)
Sensitive: 5×10-13 Пам3/с
Summarize leak

4. Sniffer test

Connections
Magnets after cryogenic test
Magnets with problems
Sensitive: 5×10-9 Пам3/с
Place of leak;
Leak can be calculated

5. Spray technique

Parts of magnets before cryotest
Magnets before cryotest
Another items for vacuum
Sensitive: 5×10-13 Пам3/с
Place of leak;
Leak can be calculated;

6. Enclosure test (main test for magnets)

Magnets
Tubes
Another items with helium inside
Sensitive: 5×10-13 Пам3/с
Summarize leak;

7. Test bench for enclosure test

Magnets
Tubes
Pressure test is done last leak test

8. Enclosure test under the helium temperature

Theoret ical leak rat es of a t ubular leak of 8 0 nm diamet er and 1 mm long
Applying law of Hagen-Poiseuille ( laminar f low, non-compressible f luides) , conservat ive approach
Temperat ure [ K]
1 .0 0 E+0 0
1 .0 0 E+0 1
1 .0 0 E+0 2
1 .0 0 E+0 3
1 .0 0 E-1 1
Gas 1 bar
Liquid 1 bar
3 .6 bar
1 .0 0 E-1 2
Molar flow rat e [ Mol/ s]
Operat ion t emperat ure at
highest operat ion pressure in LHC
1 .0 0 E-1 3
RT leak t est
at 2 5 bar
1 .0 0 E-1 4
1 .0 0 E-1 5
1 .0 0 E-1 6

9.

Enclosure test under the helium temperature
Magnets
Sensitive: 5×10-13 Пам3/с
Temperture;

10.

Bubble test