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May 22, 2011 @LAL-Orsay

Y.Sugimoto

Update of detector hall in mountain region

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Sample site

Exp-hallAcc

ess

tunn

el

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Shape of cavern

• Study of 2 sample sites in Japan– Both sites have very good geology of granite– Depth of the cavern is less than 300m

Shape of the cavern can be bullet shape rather than egg shape

B eam line

R 1 5 m

21 m

1 9m

2 0 0 ton x2

9m

2 00 to n x2

Beam line

19m

2 5m

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Access tunnel• Location of solenoid construction

– In the cavern larger cavern (L~40m?), smaller access tunnel– On surface smaller cavern, larger access tunnel– Cost is similar for both cases, but on-surface assembly is more

convenient and less risk On-surface assembly with large (h=11m) access tunnel

• Access tunnel to 2nd detector– It has to go underneath the BDS tunnel, and should not be so large – Smaller access tunnel for the 2nd detector (SiD?)– Solenoid of the 2nd detector should be carried through the larger access

tunnel, and go through the area of the 1st detector– What is the minimum size of the smaller access tunnel (input from SiD)?

• Helium compressor for solenoids– He compressors can be placed in the large access tunnel – Distance between the detector solenoid and the compressor < 200m (?)– KEK cryogenic group (Y.Makida et al.) has joined this study

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Solenoid transport

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

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Solenoid transport

100m25m

15m

Detector Service Cavern

25m

Main tunnel

11m

m

Duct tunnel

110m

m

A B C D E

A’ B’ C’ D’ E’

7.2m

to Damping Ring

25m

2 0m

3m

9m

20 0 ton x2

8.5m

Enough space fordetector solenoids

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Other issues

• Detector service caverns– What is the required size to enclose detector power

supplies, cooling plants for the detectors, power supplies and refrigerators for solenoids, etc?

• Beam line height?– To be decided in this workshop

• Do we need service tunnel and survey tunnel for accelerator?

• Can we share the access tunnel for detectors with accelerator (DR, BDS)?

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Earthquake • Belle detector after 3.11

– Bell detector was rolled out from the beam line and fixed to the ground

– 32 fixing bolts (M22) have been broken by the earthquake, 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 supportfor buildings

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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

Earthquake EarlyWarning (EEW) signal

Our own P-wave sensors

High pressureair/nitrogen vessel

Air-pads

Platform

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Towards DBD

• Impact of 3.11– Some collaborators of KEK who belong to facility

group, cryogenic group, Acc. group are occupied with repairing works at KEK and JPARC

– Hopefully, they will come back to ILC work by autumn

• In cooperation with the experts mentioned above, we will make designs necessary for the mountain site:– Underground cavern and the access tunnel– Detector solenoid/cryogenic system– Other utilities

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backup

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RDR