1. Detector hall in mountain regions
Y.Sugimoto
2011/10/13

2. Outline Detector hall Detector assembly Access tunnel Sub caverns
Construction period

3. Detector hall Bottom access tunnels at both ends
Small alcoves at the garage positions for detector opening
Top tunnel which is bored at the beginning of cavern excavation can be used as a duct tunnel

4. Detector hall
(Beam line)
Study of two sample sites in Japan shows that both sites have very good geology of granite and the depth is less than 300m
 Wall of the cavern can be upright (bullet shape cavern)

5. Detector hall Cranes are supported by 1.5m thick wall
(~13m from beam line)
Cranes are supported by 1.5m thick wall
Exp-hall should be equipped with two sets of a ton cranes
Usually one for each detector, and occasionally two cranes are used together to carry heavy (>200 ton) components such as solenoid
Two small sub-cranes at both ends of the crab trolley in order to maximize the accessible region, if necessary

6. Detector hall
(Garage position)
ILD barrel will be shifted in Z-direction during the solenoid installation

7. Detector hall Cable pits should be covered in the loading area

8. Detector hall
Detector hall has garages for crane in order to increase the crane-accessible area
Some of back-end readout electronics, power supply, cooling plants, gas bottles for gaseous detectors, etc. will be placed in the detector service cavern
Size of detector service cavern has to be specified
(End of the cavern)
Garage for crane
Detector service cavern

9. Detector hall
Inner wall

10. Detector assembly ILD baseline using vertical shaft
CMS style assembly: Barrel yoke is sliced into 3 rings
Few cm gaps between rings
One ring is made of 12 blocks: ~200 ton/block
ILD assembly using access tunnel
Each block is carried into the cavern one by one and assembled into one barrel
No gap in the barrel yoke  Less leakage field

11. Detector assembly Solenoid construction in mountainous site Option-1
Coil is divided into several modules
Each module is wound on surface, carried into the cavern, and assembled into one solenoid in the cavern
Require larger cavern
Option-2
Solenoid is constructed and tested on surface, and carried into the cavern as a whole (f~8.7m, L~8m)
Require larger access tunnel
Cost would be similar but Option-2 is less risky  We assume Option-2

12. Access tunnel
Access tunnel to the detector hall has to be quite large (11mx11m) to let ILD solenoid go through
Branch to the 2nd detector can be relatively small (8mx7.2m?) : Solenoid of the 2nd detector (SiD) can be carried into the ILD loading area, and go through the cavern to the opposite side
Helium compressors for detector solenoids can be placed along the wall of the larger tunnel after solenoid installation (?)

13. Solenoid transport A trailer with lower deck height
would reduce the tunnel size
- 225t/5axles  450t with 2-trailers
- Capable of ~7% slope

14. Tunnel crossing
Beam Tunnel
Access Tunnel
Same level as detector hall

15. Sub caverns
In addition to the main detector hall, additional small caverns are necessary
Parking area: We need (electric) cars for daily access and emergency escape
Space to take rest: WC, vending machine, smoking booth, meeting room, etc.
Warehouse for tools, materials, etc.
Helium compressor (?)
Other services ?
Large access tunnel can share some of the function

16. Construction period
Construction period is one of the most controversial issues for the shaft-less detector hall
Construction period of an access tunnel (L~1km) would be similar to that of a vertical shaft (f=18m, d~100m)
Non-CMS style assembly was once proposed for GLD as “modified CMS assembly” which can be done within the same time period as the CMS style assembly

17. CMS Style Before CCR in 2006 CMS style

18. Modified CMS style CMS style Modified CMS style 1y for Yoke assembly +
1y for Sub-detector install
Modified CMS style

19. New modified CMS style
(Basically same as modified CMS style)

20. Issues to be studied Safety Electric power Cooling water
Escape tunnel
Smoke ventilation
Solenoid quench
Vehicle for escape
Anti-seismic mechanism
Electric power
Detector
Solenoid
Liquid helium system
Crane
Light
Cooling water
Dump resister (?)
Drainage for ground water
Air conditioning
Temperature and dew point
Crane
Accessible area
Cost
Solenoid transportation vehicle ( smaller tunnel)
Liquid Helium for detector solenoid
Location of compressor
Piping compatible with push-pull
Who is responsible for it: Acc, Det, or CFS?
Sub-caverns
Parking
WC, vending machine, smoking room
Helium compressor (?)
Others?

21. Backup slides

22. Huge caverns in Japan
More than 20 huge caverns with access tunnels have been constructed in Japan for hydroelectric power plants
A 25m(W)x47m(H)x130m(L) (94,000m3) cavern can be excavated only in 14 months, and a 34mx54mx210m (250,000m3) was excavated in 21 months

23. Example of a cavern
Underground hydroelectric power plant in Japan (Kannagawa power plant)
Cavern size: 33m(W)x51.4m(H)x215.9m(L) in hard sedimentary rocks
Construction (excavation) period: ~1y for arch, ~1y for bench
Depth: d~600m  Heavy components of generators were carried into the cavern through access tunnels

24. Earthquake Belle detector after 3.11
32 fixing bolts (M22) have been broken, and Belle detector moved 6 cm on the rail
How should platforms be supported on the occasion of big earthquake?
Move with the ground?
Isolated from the ground?
Seismic isolation support
for buildings

25. Earthquake
Isolation from the ground can be achieved using air-pads, but
Enough gap between side wall is necessary
Positioning actuators should be retractable
Very flexible bellows should be placed between QD0 and QF1 to avoid damages to the inner detectors