sorry professor I found a possible error in the program.

if I set B = 0 to verify that the speed is correct I find that

scale of wall 600

if I put 1 (arbitrary units) = 100um i have that 10 km / s are 1 km / s
if I put instead 1 (arbitrary units) = 1000um I find that 10Km / s are 10Km / s

but if I calculate the radius of curvature with any value of sigma B and I find that 1 (arbitrary units) = 100um

where is the error, maybe in the time? ??? ??? ???
i need your help thanks

i'm sure (maybe!!! ;D) that the time si ten times more big of normal

1 arbitrary unit =100um yet if you put time divided by (time/10)  

e.g.
default values but B=0
traiectory linear deltax=1.01 arbitrary units, time=5.05us

1 arbitray units =100um

if you choose time 5us you get 20m/s, not 0,2Km/s
if you choose time 5us/10  get 200m/s,  real 0.2Km/s

default values B=1T
if you calculate the diametrer of traiectory you find
1=100um

as we told in the past

addition to the time that must be divided by 10 should improve two parameters.

1. at any scale,  the cursor speed should not exceed 100Km/s are not relistic higher speed.
2. the  time step, at any scale, must not exceed 2us at higher values ??the simulation is very bad

thanks