At point "A" you can see the current Stanford Linear Accelerator complex for comparison. At 2 miles (3.2 km) in length, SLAC is currently the longest linear accelerator in the world. The ILC would be nearly 10 times the length.
For further comparison, the main accelerator ring at CERN is 27 km in circumference, and the arms of LIGO are each 4 km in length.
The phrase "confirm or deny" is used when someone knows the truth of a matter but might be inclined to lie about it (deny it). In the case of data that might indicate the truth of an allegation, the phrase you are looking for is "prove or disprove" or perhaps "validate or invalidate" or "support or discredit". Data itself cannot "deny" anything.
