Planning for construction at CERN — no holes, bumps or pessimists

The participants viewing the 3x1x1 prototype cryostat on their tour, L to R: Jack Fowler, Maria Chamizo Llatos, Dan Wenman, Dave Warner, Vic Guarino, Bo Yu and Bob Flight. Credit: Bill Miller
The participants viewing the 3x1x1 prototype cryostat on their tour, L to R: Jack Fowler, Maria Chamizo Llatos, Dan Wenman, Dave Warner, Vic Guarino, Bo Yu and Bob Flight. Credit: Bill Miller
The participants viewing the 3x1x1 prototype cryostat on their tour, L to R: Jack Fowler, Maria Chamizo Llatos, Dan Wenman, Dave Warner, Vic Guarino, Bo Yu and Bob Flight. Credit: Bill Miller

Overheard at the May collaboration meeting: “The difference between a pessimist and an optimist is that a pessimist knows the details.”

Might there have been a pessimist or two among the DUNE scientists and engineers gathered at CERN during the week of April 25 to map out the very detailed logistics for the upcoming ProtoDUNE-SP installation? Despite being amused by the comment, Jack Fowler, manager of the Far Detector Integration & Installation working group, doesn’t think so.

To prepare for the logistics planning, the participants started with a guided tour. First stop: the construction site for EHN1, the building that will house the two ProtoDUNE detectors. Next was the assembly site of the 3x1x1 dual-phase prototype where the group could see and touch the cryostat, top cap and warm interface points, and the cleanroom where the detector is being assembled. They also visited the ICARUS detector — currently being upgraded for the short-baseline program at Fermilab – where Claudio Montanari described the detector’s operation and its unique design features.

“Most of these folks hadn’t been to CERN in a long time, or had never been there. It was their first chance to see the inside of a membrane cryostat and to see a TPC,” said Fowler. “They had a good time and I think it was eye-opening.”

The group planned out the transport of components to CERN from multiple institutions around the U.S. and the UK. In addition, they analyzed the internal cryogenic piping, the detector support structure and installation of the APAs, CPAs and field cages, as well as the movement, storage, testing and logistics plans for each of the parts.

“What we found were the holes – the things we didn’t know, the responsibilities that hadn’t been filled, and the little ‘tools’ that will need to be custom-made to put this detector together,” said Fowler.

The interfaces between the cryostat and the detector were also explored in detail, as was the design of a warm-and-cold APA testing station to be installed in the cleanroom in EHN1.

“Once the EOI process is complete, all the ‘holes’ will be matched with owners,” said Fowler, “and ProtoDUNE-SP should come together with very few bumps in the road.”

And very few pessimists.