1. SIS 100 Vacuum chamber Recooler String system Components
Cryogenic system – machine
Vacuum chamber
Recooler
String system
Components
SIS 100
27-28th February 2012

2. Cryogenic system – SIS100 vacuum chamber
Voltage breaker
~16 K
~ 5.5 K
Heat load ~10W/m
27-28th February 2012
Courtesy S. Wilfert, UHV group

3. Cryogenic system – SIS100 vacuum chamber
Maximum allowed average beam vacuum pressure under dynamic conditions must be p < mbar is given by beam life time
Chamber wall temperatures in cryogenic sections will range from 5K…15K
Cryopumping is used for generation of UHV pressures in the beam vacuum system
Effective cryopumping requires wall temperatures lower than 15K
At temperatures lower 15K all easily condensable gas species can be effectively cryo-condensed on the cold beam pipe wall
Excepting H2 and He, the saturation vapor pressures of all vacuum- relevant gas species at 15K are lower than mbar, and thus are negligible
27-28th February 2012
Courtesy S. Wilfert, UHV group

4. Cryogenic system – SIS100 vacuum chamber
Dpsupply=0.015 bar ~ 9.8%
Therefore the diameter choice of DN 25 is reasonable
27-28th February 2012

5. Cryogenic system – SIS100 recooling
1000 W/m2K
~ 170 W/m2K
27-28th February 2012

6. Cryogenic system – SIS100 recooling
The heat load on the supply line within on cell (12m) has to be below .5 W.
As the line is only supported by the cold iron this can be achived.
27-28th February 2012

7. Cryogenic system – SIS100 dipole
Temperature
at the outlet of magnet
Max. Temperature
at the coil of magnet
Void fraction
at the outlet of magnet
27-28th February 2012

8. Cryogenic system – SIS100, string
QP DP
Dipole +
Quadrupole
Static dynamic
dipole 5 33,9
q.pole 4 19
correc. 0 5
vacu.Ch. 0 10,6
27-28th February 2012

9. Cryogenic system – SIS100 , stringd m s
ps = 1,1 bar
pd = 1,5 bar
Tm = 4,5 K
u = Gs/Gm
pm=3 bar
u = 0,73
Recycling by ejector, below 17 W additional heater
27-28th February 2012

10. Cryogenic system – SIS100 , string
Thermo-hydraulic mock-up
Unfortunately the test could not started by now, due to a delay in delivery and a failure in the refrigerator;
but it was already a successful training for the dipole manufacturer.
Tests will follow.
27-28th February 2012

11. Cryogenic system – SIS100, cool down
magnet itself
- by convection, helium flow through magnet (no helium flow passes through supply and return line)
in machine
- the full equipment has a design pressure of 18 bar, therefore during cool down the supply pressure can be increased up to 18 bar to increase the mass flow through the magnets.
For this operation the recooler can transfer heat of ~80 W
- by suppling the supply line by the shield line from the endbox side the cool down can be equalized.
- magnet cooled by convection (and conduction)
- the maximal mass flow available for cool down is given by
a) the pressure drop in the system (designed for 1000 g/s triangular cycle)
b) the available cooling capacity of the refrigerator ( ramp duty .5)
Cool down time : ~ 9 d (depending on the final cold mass)
27-28th February 2012

12. Cryogenic system – SIS100
Vacuum barrier
Max. length of section of insulation vacuum: 150 m
An each sector have to be cooled down/ kept cold independently
27-28th February 2012

13. Cryogenic system – SIS100 Feed box
27-28th February 2012

14. Courtesy M.Konradt
27-28th February 2012

15. Cryogenic system – SIS100 End box
To minimizes the feed-troughs no valve systems with positioners with external potentiometer
27-28th February 2012

16. Amount: 10 (+2) 6 3 1 +2 Shorter version
Cryogenic bypass line(including Bus Bars)
Shorter version
The maximum length of one continuous vacuum is ~150m.
Each sector should be kept cold independent.
End box
Terminates helium flow
Cool-down/warm up connections
Bus bar connection
feed in
Supplies helium flow
Electrical supply and/or bus bar connection
By pass line
helium connection
bus bars
=> with vacuum barrier
Amount: (+2)
27-28th February 2012

17. Cryogenic system – SIS100 By-pass line
Connection box
End caps:
Termination of the cold section => CWT
Feed out:
CWT
Transferring helium lines and bus bars into the bypass line
Soldering of busbar connections
Support of pressurized tubes (bends)
Flipped version
Magnet version:
CWT
Transfer of two QP bus bars
Soldering of bus bar connections
Feed trough of by-pass lines
Amount: 6 (+4 Ref.mag) extended
27-28th February 2012

18. Cryogenic system – SIS100 By-pass line
Cryogenic bypass line (including Bus Bars)
Shorter version
The maximum length of one continuous vacuum is ~150m.
Each sector should be kept cold independent.
End box
Terminates helium flow
Cool-down/warm up connections
Bus bar connection
feed in
Supplies helium flow
Electrical supply and/or bus bar connection
By pass line
helium connection
bus bars
=> with vacuum barrier
Amount: (+2)
27-28th February 2012

19. Cryogenic system – SIS100 Electrical Supply
4 K
50 K
Current leads
0.11 W/ kA
0.065 g/s /kA
13KA
1.4 W
0.85 g/s
Box
20 W
150 W
Per cable
3 W
22 W
Link
0.1 W/m
1.2 W/m
AC losses (triangular cycle.. Very conservative)
0.2 W/m/cable
Eddy current losses in transfer line
negligible
Length
110 m
Difference of level
15 m
Inner diameter of cable m
Total load /cable
~ (.1/6+.2) *110 =23.8 W
Total load/ circuit
~ W
27-28th February 2012

20. Cryogenic system – SIS100 Electrical Supply
The two bus bars of one electrical circuit are one hydraulic line. One bus bar will be supplied by supercritical helium (2.95 bar, 4.4 K). Within the current lead box part of the helium stream will by throttled into a recooler. The recooler provides liquid helium at 4.4 K for the second bus bar of the circuit. The helium vapour from the recooler will be fed into a separate line down to the transfer line towards the refrigerators at tunnel level. This return line is a common one for all recooler in the feed box.
The two bus bars of one electrical circuit are in parallel. The return of the helium is in a separate line. Both bus bars will be supplied by supercritical helium (2.95 bar, 4.4 K). To keep the return supercritical the pressure drop of the return line may be lowered in respect to the cable by increasing the diameter.
As a third option this scheme could be operated in the two-phase region, as bubbles always can travel to the top
27-28th February 2012

21. Cryogenic system – SIS100 Electrical Supply
Version A
Version B
Version C
27-28th February 2012

22. Cryogenic system – SIS100 Testing
Component test and assembly test are required for:
Bypass line including vacuum barrier with busbar system
Electrical supply system
These test should consist from an individual component test and a system test
(at string test facility)
Feed box may be assumed as a reliable 4K design.
27-28th February 2012

23. Cryogenic system – SIS100 Electrical Supply
27-28th February 2012

24. Cryogenic system – SIS100 control
Cryogenic control
Current lead control
27-28th February 2012