Detector hall in mountain regions Y.Sugimoto 2011/9/14 JSPS Kickoff Meeting@Sendai

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

An example of Asian mountain site Exp-hall Access tunnel

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

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

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

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

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)

Detector hall Cranes are supported by 1.5m thick wall Exp-hall should be equipped with two 200+20 ton cranes: usually one for each detector, and occasionally two cranes are used together to carry heavy (>200 ton) components such as solenoid

Detector hall 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 Size of detector service cavern has to be specified Garage for crane Detector service cavern

Inner wall

Tunnel crossing Beam Tunnel Access Tunnel Same level as detector hall

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

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

Backup slides

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

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)

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