In late 2006, a component of the Karlsruhe Tritium Neutrino Experiment (KATRIN) traveled from Deggendorf, Germany, to a laboratory in Karlsruhe, only 400 kilometers away. The trip wouldn’t have been a notable event, except that the spectrometer, an instrument used to measure the masses of particles, followed a near-9000-kilometer route to get from one town to the other.
To say it was difficult to move the spectrometer would be an understatement. Measuring almost 10 meters at its widest point and weighing 200 tons, the device was too large and too heavy to be transported along the roads between the two towns. Because the design of the detector called for a half-mile of specialized vacuum-tight welding between sheets of stainless steel, it had to be shipped from the Deggendorf site in one piece.
Starting in 2010, the KATRIN experiment will take on the challenge of directly determining the mass of the neutrino, an elusive particle without electric charge. Because neutrinos cannot be detected directly, KATRIN will look for how much mass is missing when tritium decays, a process known to emit neutrinos. To do this, the experiment will rely on the capabilities of the specially-designed large spectrometer.
As it traversed the course of its European odyssey, a team of a dozen scientists fretted over the spectrometer’s every move. They watched, guided, worried, and then celebrated when, having navigated a carefully choreographed route across water and land, the instrument finally arrived in Karlsruhe after 63 days of travel.