Add a field of type Solenoid to the fields of the compact description.
<fields> <field type="Solenoid" name="GlobalSolenoid" inner_field="5.0" outer_field="-0.6" zmax="1000" outer_radius="144*cm+(2+1)*34*cm"/> </fields>
The inner_field is applied to radii with the outer_radius while the the outer_field is applied to radii outside this distance.
The zmax attribute specifies an absolute z value after which the field is no longer applied. (There is no "fall off" implemented.)