=head1 Tagger Magnetic Field Map Subject: magnetic field map From: "Guangliang Yang" Date: Tue, 27 Sep 2005 15:52:57 +0100 To: "Richard Jones" CC: Please download the magnetic field map from http:/nuclear.gla.ac.uk/~yang/Tagger/. There are two field maps, one with the quadrupole turned on and one with it removed. Which is which is seen from the name of the file. The coordinate system I used is the same as you required. The origin is at the radiator position, the z axis is along the incoming main electron beam, the y axis is perpendicular to the tagger mid plane, and the x axis is opposite to the electron beam bending. The magnetic field map covers a range of x: -340 to 10 cm, step: 1cm; y: 0 to 1.5 cm , step: 0.1cm; z -10 to 1600cm, step 1cm. The straight line focal plane can be defined by two points (-70.663, 423.7086) and (-239.8134, 1388.486) . (units cm.) The co-ords for the first magnet pole shoe: X= 28.60552 Y= 1.5 Z= 304.86853 X= -17.34935 Y= 1.5 Z= 300.11956 X= -3.01983 Y= 1.5 Z= 610.90074 X= -48.97470 Y= 1.5 Z= 606.15177 The co-ords for the second magnet pole shoe: X= -16.42643 Y= 1.5 Z= 653.28350 X= -62.30180 Y= 1.5 Z= 647.81969 X= -52.81217 Y= 1.5 Z= 958.78629 X= -98.68754 Y= 1.5 Z= 953.32248 The co-ords for the vacuum chamber: X= 30.25178 Y=+- 3.8 Z= 303.53067 X= -18.68722 Y=+- 3.8 Z= 298.47332 X= -25.98418 Y=+- 3.8 Z= 369.08453 X= -68.22507 Y=+- 3.8 Z= 418.49763 X= -258.26128 Y=+- 3.8 Z= 1502.39221 X= -205.65216 Y=+- 3.8 Z= 1511.60084 X= -73.71934 Y=+- 3.8 Z= 957.80529 X= -51.50141 Y=+- 3.8 Z= 960.45148 X= -14.75792 Y=+- 3.8 Z= 651.97178 X= -1.68197 Y=+- 3.8 Z= 612.54698 X= 30.25178 Y=+- 3.8 Z= 303.53067 The co-ords for the vacuum chamber are based on the current design. Further modification is needed for the high energy end. Once I finish the modification, I will give you the new co-ords for this part. If you need any further information, please let me know. Regards Yang