The brass plug monument system for doubler alignment
Charles T. Murphy · 1981
The system of brass plugs set in the Main Ring tunnel floor for use in radial alignment of Doubler elements is described. Considerations leading to the choice of plug positions and properties are discussed. The quantitative relationship between the plugs and the Doubler orbit is presented in sufficient detail so that they can be used by anybody to align Doubler elements both radially and along the beam. Neither the origin or the accuracy of the system is discussed in detail.