opera C0_01_msl_no_holes_no_sym.comi: Code by Aleksey. 4-layer MSL-MSR without holes. 5cm mesh width for inner components D1: single layer D2: implementtaion of a dipole field in Opera D2_1: systematic study to change the number of layers and see its influence on the field produced in the outermost layer D3: based on a code written by Maedeh to learn how to implement scalar potential bounday condition D4: implemented a coil with different dimensions to see the magnetic field response by a current applied in it D6: realized implementation of dipole field by making a shell on the edge of the exterior.