[Clas12_software] new magnetic field in gemc

[Maurizio Ungaro]

We have new magnetic field for the solenoid in gemc: srr-solenoid.
To use it, at the command line:

-HALL_FIELD=srr-solenoid

(instead of itep-solenoid)

The table has been generated by Lionel Quettier.

More details from Lionel:

SRR stands for system requirement review: it is the first meeting we had
with the vendor to launch the project, and to be sure they have
correctly understood our specifications, our constraints and our
requirements.

The calculation is made using purelly analitycal method (solving on Biot 
& Savart laws, without finite elements) assuming purely axisymetrical 
coils around the main axis (beam axis).
Magnet center is located at 0,0,0.

best regards,
mauri