1. Detector hall in mountain regions
Y.Sugimoto
2011/9/14
JSPS Kickoff

2. ILC in mountain regions
Candidate sites of ILC in Japan locate in mountain regions
Depth of the detector hall for these candidate site is >100m  Default path for detector/BDS installation is access tunnel rather than vertical shafts
Detector assembly method will be different from CMS style
Design of the detector hall in mountain regions is being studied collaborating with KEK CFS group

3. An example of Asian mountain site
Exp-hall
Access tunnel

4. A possible design of exp-hall
With vertical shafts
Without vertical shaft
Bottom access tunnels at both ends (for 2 detectors)
Small alcoves at garage positions for detector opening
Top (duct) tunnel is bored first, and then the arch part of the cavern is excavated

5. Detector assembly
Assembly hall locates at the entrance of access tunnel where wide flat surface and wide roads exist
Detector would be assembled to relatively small pieces (<400 ton) at the assembly hall, carried to the cavern through the access tunnel, and integrated to the large detector inside the cavern (Similar to “modified CMS style assembly” which was proposed by GLD group in 2006)
Barrel iron structure would be divided in f (and R) direction, rather than Z direction
Solenoid would be constructed on surface
Detailed study on the assembly method is necessary

6. 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 can be carried into the cavern through the larger tunnel 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

7. Solenoid transport - 225t/5axles  450t with 2-trailers
- Capable of ~7% slope

8. Detector hall
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)

9. Detector hall Cranes are supported by 1.5m thick wall
Exp-hall should be equipped with two ton cranes: usually one for each detector, and occasionally two cranes are used together to carry heavy (>200 ton) components such as solenoid

10. Detector hall
ILD barrel will be shifted in Z-direction during the solenoid installation

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

12. Detector hall
Detector hall has garages for crane in order to increase the crane-accessible area
Size of detector service cavern has to be specified
Garage for crane
Detector service cavern

13. Inner wall

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

15. 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

16. 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

17. Summary
Design study of detector hall in mountain region is in progress
In this design, ILD barrel will be assembled in modified-CMS style
Solenoid assembly/test will be done on surface
There are many issues to be studied for the exp-hall optimization; some of them are common to the CMS style assembly:
Configuration of He system (He compressor location, piping compatible with push-pull, etc.)
Power supply of Solenoid (location, electricity, cooling)
Gas ventilation in case of solenoid quench
Total power consumption (He compressor, detector, lighting, etc.)
Cooling water (detector, power supply, compressor, etc.)
Air conditioning (temperature and humidity)
Drainage of ground water
Anti-seismic mechanism
Human safety including escape route
Other utilities (W.C., vending machine, smoking room, etc.)
………………….
Detailed civil construction design of underground caverns/tunnels will be done by a company in latter half of 2011 FY

18. Backup slides

19. Construction period
Construction period is one of the most controversial issues for the shaft-less exp-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

20. CMS Style Before CCR in 2006 CMS style

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

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

23. 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

24. 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