Modification of LAMPF´s magnet-mapping code for offsets of center coordinates

One of the magnet measurements performed at the Los Alamos Meson Physics Facility (LAMPF) is the determination of the cylindrical harmonics of a quadrupole magnet using a rotating coil. The data are analyzed with the code HARMAL to derive the amplitudes of the harmonics. Initially, the origin of the polar coordinate system is the axis of the rotating coil. A new coordinate system is found by a simple translation of the old system such that the dipole moment in the new system is zero. The origin of this translated system is referred to as the magnetic center. Given this translation, the code calculated the coefficients of the cylindrical harmonics in the new system. The code has been modified to use an analytical calculation to determine these new coefficients. The method of calculation is described and some implications of this formulation are presented. This transformation has been tested with a few simple cases and has been found to be correct in these cases.<>