Is this needed? Or could the reception be done in the surface?
I mean, the interesting question is now: how much time will it take to repeat the experiment, either by others or by the CERN but with other reception point?
To put that in perspective: a 20 part per million difference in speed over 730 km distance is about 15 metres. So details about the detector are relevant, but they obviously know that.
"three large experimental halls, each about 100 m long, 20 m wide and 18 m high and service tunnels, for a total volume of about 180,000 cubic metres"
http://www.lngs.infn.it/home.htm