# Meeting 2015 08 21¶

## Generic settings¶

/N02/det/trackMaxSteps 1000000000
/N02/det/trackMaxLen 10 km
/gun/energy 10.9181415106 MeV
/N02/prec/setDeltaOne 1.0e-2 mm
/N02/prec/setDeltaInt 1.0e-5 mm
/N02/prec/setEpsilonMin 1.0e-3
/N02/prec/setEpsilonMax 1.0e-3
/N02/prec/setDeltaChord 0.25 mm

## Experiment 1¶

/N02/det/stepMax 20. mm (i.e., stepMax = 20mm)
epsilonMax = epsilonMin = epsilon
The mean square error doesn't seem to vary.
The error, however, keeps growing with distance.
Why?

Error (y) vs. Distance (x) (only illustrative):

epsilon Simulation Time Integration Steps Mean Square Error
1.0e-3 0m13.725s 16500010 294
1.0e-4 0m13.725s 16500010 294
1.0e-5 0m13.725s 16500010 294
1.0e-6 0m21.815s 38500010 294
1.0e-7 0m27.980s 60500010 294
1.0e-8 0m41.054s 104499999 294
1.0e-9 0m55.830s 159500010 294
1.0e-10 1m25.948s 269499999 294
1.0e-11 2m17.996s 456500010 294
1.0e-12 3m50.224s 786518324 294

## Experiment 2¶

/N02/prec/setEpsilonMin 1.0e-3 (i.e, epsilon = 1.0e-3)
/N02/prec/setEpsilonMax 1.0e-3
Mean Square Error measured for first 15000 points (final time differs a lot, maybe we should consider some other measurment)

stepMax [mm] Simulation Time Integration Steps Mean Square Error
0.2 13m34.816s 550000011 0.00002
1 2m51.026s 110000000 0.0006
2 1m28.192s 55000000 0.002
5 0m33.121s 22000000 0.017
10 0m21.907s 22000010 0.068
20 0m13.797s 16500010 0.27
50 0m8.319s 13200010 1.65
100 0m7.179s 13200020 6.34
150 0m6.848s 13200020 13.68
200 0m6.382s 12650020 23.31