The one-dimensional s=1/2 Heisenberg ferromagnet (C6D11ND3)CuBr3, perdeutero cyclohexylammonium opper(II) bromide (CHAB-D14), has been synthesized and its crystal structure has been determined with neutron diffraction. Like the chlorine isomorph CHAC, CHAB is orthorhombic, space group P212121, z = 4, cell dimensions a = 19.561(8) Å, b = 8.678(4) Å, and c = 6.381(2) Å at 54.5 K. The ferromagnetic Cu-chains run along the c-direction. Two bromine ligands form symmetrical bridges between the copper ions. The bridging angles are 82.31 and 83.49° for the Cu-Br(2)-Cu and Cu-Br(3)-Cu bonds, respectively. Adjacent chains are well isolated from each other by the cyclohexyl groups in the ac-planes, and by the ND3 moieties in thebc-planes.