Implementation of Spin Rotator.

geant4/spin_rot/run/eff_length.m

@@ -0,0 +1,61 @@
+% Electric field
+
+% Read file (check the number of header lines) and assing variables.
+filename = 'E3D_cap_symm.map';
+[x y z Ex Ey Ez] = textread(filename,'%f %f %f %f %f %f','headerlines',8);
+
+z_ind = find (x==0 & y==0); % Determine indices of the points along z axis.
+z_p = z(z_ind);   % z values along z axis
+Ex_p = Ex(z_ind); % Ex field profile along z axis
+
+plot(z_p,-Ex_p*0.8e-8,'m-');
+
+%Calculate effective field length l_eff = Int(Ex dz) / max(Ex).
+
+z_step = max(diff(z));
+i_center = find (x==0 & y==0 & z==0); % Field center index
+if Ex(i_center) < 0, % If the field at center is negative use min, otherwise max.
+   l_effE = sum(Ex_p)*z_step/min(Ex_p);
+else
+   l_effE = sum(Ex_p)*z_step/max(Ex_p);
+end
+   
+ylim = get(gca,'YLim');
+hl1 = line([-l_effE/2 -l_effE/2],[ylim(1) ylim(2)]);
+hl2 = line([ l_effE/2  l_effE/2],[ylim(1) ylim(2)]);
+set(hl1,'Color','m'); set(hl2,'Color','m'); 
+text(0.75,0.8,['Eff. length E = ',num2str(l_effE,3), ' cm'],'Units','Normal','Color','m')
+
+xlabel('z coordinate (cm)','FontSize',14)
+ylabel('EM Field (arb. unit)','FontSize',14)
+title('Field profile along z axis','FontSize',16)
+
+hold on
+
+% Magnetic field
+filename = 'B3D_iron1.map';
+[x y z Bx By Bz] = textread(filename,'%f %f %f %f %f %f','headerlines',5);
+
+z_ind = find (x==0 & y==0); % Determine indices of the points along z axis.
+z_p = z(z_ind);   % z values along z axis
+By_p = By(z_ind); % By field profile along z axis
+
+plot(z_p,-By_p,'b-');
+
+%Calculate effective field length l_eff = Int(By dz) / max(By).
+
+z_step = max(diff(z));
+i_center = find (x==0 & y==0 & z==0); % Field center index
+if By(i_center) < 0, % If the field at center is negative use min, otherwise max.
+   l_effB = sum(By_p)*z_step/min(By_p);
+else
+   l_effB = sum(By_p)*z_step/max(By_p);
+end
+   
+ylim = get(gca,'YLim');
+hl3 = line([-l_effB/2 -l_effB/2],[ylim(1) ylim(2)]);
+hl4 = line([ l_effB/2  l_effB/2],[ylim(1) ylim(2)]);
+text(0.75,0.75,['Eff. length B = ',num2str(l_effB,3), ' cm'],'Units','Normal','Color','b')
+text(0.03,0.8,{'C-magnet 20x40 cm poles','Symm. capacitor voltages'},'Units','Normal','FontSize',12)
+set(gca,'FontSize',14)
+axis([-50 50 0 8e-7])