The Advanced Hydrotest Facility (AHF) large bore quadrupole focusing magnet system

The Advanced Hydrotest Facility (AHF) at Los Alamos will provide proton radiography of large-scale, dynamic events. The large bore (Case II) quadrupole focusing magnets are a subsystem in this facility, consisting of four complete imaging lines with a total of eight imaging plates and 52 quadrupole magnets. Each large bore quadrupole has an inner winding diameter of 660 mm and provides a gradient of 10.4 T/m with a 300 mm field of view. Each magnet is a two-layer saddle, contained by a three cm steel shell. The conductor is a Rutherford cable, soldered into a C-shaped copper channel. The magnets are cooled by the forced-flow of two-phase helium through coolant pipes. Since the winding was calculated to absorb bursts of 0.35 J/kg irradiation, both NbTi and Nb/sub 3/Sn designs are being considered.