I think if there was contest on which ATLAS sub-detector had the most parties, TileCal would be a serious contender, if not the outright winner. The people of TileCal are experts at finding an excuse to have a BBQ. Past party reasons have included, ‘100 power supplies installed’, ‘128 power supplies installed’, ‘ATLAS week has started’, ‘ATLAS week has ended’, ‘ATLAS week ended 10 days ago’, ’10 weeks until the next ATLAS week’. In other words, we need no reason. Oddly enough it has been nearly three weeks since we have had a BBQ and honestly I am experiencing some serious withdrawal.
Most of the BBQs take place at building 171 which is our surface assembly building. TileCal is a ‘sampling calorimeter’ meaning that it is composed of tiles of scintillator sandwiched between tiles of lead. This scintillator/lead pattern repeats many, many times along the detector. When particles pass through the lead, they are slowed down. When they pass through the scintillator they produce light. We measure the light using photomultiplier tubes. The amount of light measured is proportional how much energy the particle deposited in the scintillator. Since the detector was built on surface but had to be transported underground, 256 pie shaped wedges were assembled on surface. The first wedges were transported underground in 2004, the last coming down in 2006. 64 of these wedges can be barely seen in the following picture. At the outer ring, there are these dark blue boxes. One of those boxes holds the power supplies for one wedge. The active detector (the scintillator and lead tiles) extended back behind the supply but are completely hidden at this point.
Since all the wedges are now down in the pit, the assembly building is largely empty making it the perfect place for a little BBQ. The advantage to working with a large international group is that the food is never just burgers and fries. The Spanish for example clearly have an infinity of ways to prepare pork. They show up every time with something different. The Brazilians are always arriving with some exotic type of meat. One day they came with at least 100 seasoned chicken hearts in a bowl. The Russians pretty much have cornered the sausage and hard liquor department. Occasionally the Lebanese bring a deep fryer to make falafel, which is to die for. And no one cannot beat the Italians at desserts.
Three weeks and no BBQ though? Clearly we are going to have to conjure up reason. How about ‘256 wedges still installed underground’? Why not?
