This proposal would like to map the diffraction patterns of Gd3Al5Gd12 (GAG) using the high flux diffraction instrument WISH. It is of great interest to solve the magnetic structure of GAG in applied magnetic field and in particular in the antiferromagnetic (AF) region as defined by susceptometry. The magnetic structure in the AF region for the analogous compound Gd3Ga5O12 (GGG) has eluded clarification for over 20 years while the profile in GAG, obtained via recent measurement on LET, appears simpler. These measurements will determine the universal nature of exotic phenomena observed in GGG, namely the hidden multipolar order with its associated decagon spin loops that permeate the (H,T) phase space.