L=260;
Le=120;
w=60;
a=w/3;
t=10;

Point (1) = {0, -L/2, -t/2};
Point (2) = {w, -L/2, -t/2};
Point (3) = {w,    0, -t/2};
Point (4) = {w,  L/2, -t/2};
Point (5) = {0,  L/2, -t/2};
Point (6) = {0,  Le , -t/2};
Point (7) = {0, -Le , -t/2};

Line (1) = {1, 2};
Line (2) = {2, 3};
Line (3) = {3, 4};
Line (4) = {4, 5};
Line (5) = {5, 6};
Line (6) = {6, 7};
Line (7) = {7, 1};

Line Loop (8) = {1, 2, 3, 4, 5, 6, 7};
Plane Surface (9) = {8};

Extrude {0, 0, t} { Surface{9} ; }

Physical Volume (1) = {1};
Physical Line   (2) = {40, 36};
Physical Line   (3) = {24};
Physical Point  (4) = {3};
Physical Surface (5) = {46,45,41,37,33,29,25,21,9};

Field[1] = MathEval;
Field[1].F = "Fabs(Fabs(y/5)-1)";

Field[2] = Threshold;
Field[2].IField  = 1;
Field[2].DistMin = 1.0;
Field[2].DistMax = 10.0;
Field[2].LcMin   = t/8.0;
Field[2].LcMax   = t/2.1;

Background Field = 2;
