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

Outline Detector hall Detector assembly Access tunnel Sub caverns Construction period

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

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)

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 200+20+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

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

Detector hall Cable pits should be covered in the loading area

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

Detector hall Inner wall

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

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

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 (?)

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

Tunnel crossing Beam Tunnel Access Tunnel Same level as detector hall

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

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

CMS Style Before CCR in 2006 CMS style http://www-project.slac.stanford.edu/ilc/acceldev/beamdelivery/rdr/docs/CCR_surface/BDS_schedule.pdf

Modified CMS style CMS style Modified CMS style 1y for Yoke assembly + 1y for Sub-detector install Modified CMS style http://www-project.slac.stanford.edu/ilc/acceldev/beamdelivery/rdr/docs/CCR_surface/BDS_schedule.pdf

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

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?

Backup slides

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

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

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

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