Illuminating fiducials

Michael O’Boyle marks the floor of the M4 beamline. The marks indicate where the beamline magnets, seen in the background, will be positioned. Photo: Christine Ader

Moving beamline magnets into place is a meticulous business.

Pictured here is Michael O’Boyle in the M4 beamline using a device that goes by the fancy name of “spherically mounted retroreflector,” or SMR, to precisely mark where the magnets for the Mu2e experiment will be located.

A laser tracker follows the SMR wherever it goes, and a computer reads the distance between the SMR and the desired point (in this case, the desired floor position of the magnet). The SMR is moved until the computer says that the distance between the desired point and the SMR is 0 (when the computer displays that X=0 and Y=0) — that is, when the SMR has finally hit the spot. The spot is then marked with a label and magic marker.

The process is repeated for each magnet.

Crews worked for more than two days marking magnet coordinates. They included Craig Bradford, Gary Crutcher, Michael O’Boyle, Gary Teafoe, Chuck Wilson and Randy Wyatt.

The magnets will be used to direct particle beams from the Muon Delivery Ring to the Mu2e experiment. You can see the magnets in the background, waiting to be moved. Now that nearly all the coordinates are marked, iron workers will come in to move the magnets into position.

(By the way, don’t be fooled by the light coming from the SMR. SMRs don’t light up. But like most reflective surfaces, they do reflect camera flashes.)

Editor’s note: If you have an interesting photo that portrays a little-known slice of Fermilab life, submit it through Fermilab at Work. Include a short description and include the names of the people shown.