Dipole negative K0
When I compare (opal 1.6 and opal 1.9) the beam line of the PSI Gantry 2, I have noticed the problem, that negative K0 values of the Dipole AMF2 cause troubles (maybe in the creation of the reference trajectory). Even, an alternative Implementation with a positive K0 and a rotation (PSI) of pi doesn't solve the problem and gives the same output.
The Implementation of the dipole is:
AMF2: SBEND, K0=-0.804017, //<--- negative magnetic field strength L=1.4929, ELEMEDGE=42.6615, FMAPFN="HardEdge.T7", //PSI = Pi, //<---- Rotate like that DESIGNENERGY=7.381e+01, GAP=.1;
NOTE: Why do I think, that the negative K0 causes the problem? Because just some elements before the dipole AMF1 has precisely the same attributes, except a positive K0 and matches the with OPAL 1.6.
The complete .in are here. 70MeV_Gantry2_OPAL1.6.in & 70MeV_Gantry2_OPAL1.9.in
The Fieldmap: HardEdge.T7
If I use positive K0 values, the rms of OPAL 1.6 and OPAL 1.9 match again. Plot below (made out of .stat file made with pyOPAL Tools)
Does someone has an idea where this missmatch come from?