boundary_types = p,p
boundary_values = 3,6
initial_gradients =          1.4,  0.5,  -10,  -10, -1.4,  1.5,  -10,  -10,     0,  -10,  -10, -1.4,  1.5,  -10,  -10,     0,  -10,  -10, -1.4,  1.5,  -10,  -10 
reflection_path =   (4,2), (3,2),(3,3),(2,4),(1,3),(0,4),(0,3),(1,4),(2,3), (3,4),(2,5),(1,4),(0,5),(0,4),(1,5),(2,4), (3,5),(2,6),(1,5),(0,6),(0,5),(1,6),(2,5), (3,6) 
grid_size = 7
max_radius = 70%
