Alignment of the beam transport line of KEK B-factory

KEK B-factory (KEKB) is an electron-positron collider ring with asymmetric energy of 8.0 GeV and 3.5 GeV. The 8 GeV electron and 3.5 GeV positron beam accelerated with the injector linac are transferred to the ring through the beam transport line (BT). The beam transport line consists of 2 independent beam lines for electrons and positrons. To avoid various operational complications, the two beam lines have no common magnets except for the first magnet which separates the 2 beams from the linac. Because the BT tunnel is not wide enough to lay out beam lines horizontally, they are stacked vertically. This paper presents the construction of the beam transport line, the authors describes how the positioning and alignment of magnets have been made and which equipment and devices have been used. The alignment precision of neighboring magnets is expected to be 0.21 mm