Field Distributions of Injection Chicane Dipoles in SNS Ring

3D computing simulations have been performed at ORNL to study the magnetic field distributions of two injection chicane dipoles in the SNS ring. The simulation studies have yielded the performance characteristics of the dipoles and generated magnetic field data in three dimensional grids. Based on the simulation data, a 3D multipole expansion of the chicane dipole field, consisting of generalized gradients and their derivatives, has been made. The expansion is quasi-analytical by fitting numeric data into a few interpolation functions. A 5^th-order representation of the field is generated, and the effects of even higher order terms on the field representation are discussed.