Odds in the new magnet field map
I wrote a
small Root macro (map.C)
for plotting the magnetic field strength as a function of
radius and z position for a fixed phi angle given in the field map
file. The phi angle
in the field map runs from 0 to 45 degree for one octant and I picked
some phi angles
for plotting the x and z component of the magnetic field.
(The y axis has the unit kiloGauss, phi=0deg means center of "left
coil", phi=45deg means center of "right coil")
Left
Right
New field map: Bz_vs_Z_phi5deg_sideviewZ
Old field map: Bz_vs_Z_phi7deg_sideviewZ
(beware: z-axis is
mirrowed here, my mistake)
=> spikes and bumps ...
As you can see there
are a lot of irregular (huge) spikes esp. in the left plot
and some
strange field behaviours in the exit region (z~230cm).
Quick shot: the old field map looks
a bit better, still some spikes but less extreme
and NO bump at Z~230. To be verified with more plots ...
Here is an overview
of all the plots I made with the new field map:
=> This might/will affect the tracking since one irregular field
value on the grid
will affect the field interpolation
within the 8 surrounding grid "cubes"
("trilinear" field interpolation
based on a 3D data grid)
Here are the links to the individual plots of the new field map:
Bx_vs_Z_and_R_phi7deg.pdf
Bx_vs_Z_and_R_phi7deg_sideviewR.pdf
Bx_vs_Z_and_R_phi7deg_sideviewZ.pdf
Bx_vs_Z_and_R_phi15deg.pdf
Bx_vs_Z_and_R_phi15deg_sideviewZ.pdf
Bx_vs_Z_and_R_phi30deg_sideviewR.pdf
Bx_vs_Z_and_R_phi30deg_sideviewZ.pdf
Bx_vs_Z_and_R_phi37deg.pdf
Bx_vs_Z_and_R_phi37deg_sideviewR.pdf
Bx_vs_Z_and_R_phi37deg_sideviewZ.pdf
Bz_vs_Z_and_R_phi0deg_sideviewZ.pdf
Bz_vs_Z_and_R_phi5deg_sideviewZ.pdf
Bz_vs_Z_and_R_phi7deg.pdf
Bz_vs_Z_and_R_phi7deg_sideviewR.pdf
Bz_vs_Z_and_R_phi7deg_sideviewZ.pdf
Bz_vs_Z_and_R_phi15deg.pdf
Bz_vs_Z_and_R_phi30deg.pdf
Bz_vs_Z_and_R_phi37deg.pdf
Bz_vs_Z_and_R_phi40deg_sideviewZ.pdf