1. A very first look at siting issues
Albert De Roeck – Martin Gastal – Harry Shakeshaft – Theo Prins
Implementation

2. Finding an appropriate location to host MilliQan
Constraints:
Behind at least 5m of concrete from the IP (see July tests)
Space to accommodate the detector (foreseen to be 1m x 1m x 3m)
Floor loading to be compatible with detector and its support structure (between 3500Kg and 6000Kg )
Power supply to be available, with possibility to add other services
Selected experimental area should remain clear of “visitors” during data taking
Proposed location the PX56 Observation and Drainage gallery

3. PX56 Observation and Drainage gallery
UXC55 Experimental Cavern
Drainage Gallery
The PX56 drainage gallery was used during the excavation phase of the CMS experimental area.
It links the 2 CMS shafts PM54 and PX56 together

4. PX56 Observation and Drainage gallery
The gallery has a basic shotcrete finish

5. PX56 Observation and Drainage gallery
Basic lighting and drainage available but not cooling water
Use for CMs staff to access the PX56 platform
Dimensions: 2.78m in height
2.73m in width

6. PX56 Observation and Drainage gallery
Harry and Theo identified a location that would fit the space requirements of the detector

7. PX56 Observation and Drainage gallery
The detector would need to be mounted on a support structure that would allow pointing it at the IP and also putting it in stowed configuration to allow access through the gallery
During TS3, should this proposal be endorsed, we will ask the CERN survey team to carry out a 3D scan of the area.
It will allow high precision integration studies to start

8. PX56 Observation and Drainage gallery
The selected position would fit the constraints that were considered:
3m x 1m x 1m object will fit – but tight, supporting structure should not ad any material at extremities
Distance to IP in the range [20m ; 35m]: 33m
Thickness of rock: 16.5m
The resulting tilt will be 54deg below horizontal

9. PX56 Observation and Drainage gallery
Pros and Cons
Pros
Cons
Own interlock access
No visitors when beam is ON
Access to detector only during technical stops
Detector parts can be lowered through PX56 on to shaft platform
All parts have to pass through door 1,2m x 2m
Electricity and cable trays already installed
Proximity of other services (water, gas..)
No neighbouring equipment.

10. Next Steps
Finalise first integration study using 3D scan of proposed area
Assess need for services (power, gas, cooling)
Assess safety implications
Fire load, evacuation procedures
Upgrade to safety systems (smoke monitors, temperature sensors…)
Obtain formal approval for use of the area
Already checked with LHC -> not involved in decision making process
Civil Engineering group will install new monitoring equipment prior to excavation work for HL-LHC
CMS will be driving the approval process
Carry out an initial study of the supporting structure
Handle weight
Alignment requirements
Allow a stowed configuration