elastic scattering length for

Dear FLUKA experts

Looking at the FLUKA output of a Carbon-12 ion run (400 MeV/nuc) I find
the information listed below about scattering lengths. The elastic
scattering length values appear very high to me (1E30 cm). It looks
similar to the value FLUKA is reporting for vacuum. The table tells me
even that vacuum has a shorter elastic scattering length than
hydrogen!?!?!?!?!
I guess there is a simple explanation for that. I would be grateful if
one of you could advice me on that.
Thanks in advance.

Best regards
Helmut

Material Atomic Atomic Density Inelastic Elastic Radiation Inelastic
Number&Name Number Weight Scattering Scattering Length Scattering
                                                           Length for Length for Length for

  2 VACUUM 0.000 0.000 0.000 0.1000E+31 0.1000E+31 0.1000E+31 0.1000E+31
  3 HYDROGEN 1.000 1.008 0.8370E-04 0.8589E+05 0.1195E+35 0.7532E+06 0.6523E+09
  6 CARBON 6.000 12.01 2.000 12.91 0.5000E+30 21.35 18.23
 32 WATER 3.333 6.005 1.000 21.88 0.1000E+31 36.08 45.12
 33 CO 7.000 14.01 1.000 27.78 0.1000E+31 37.42 38.44
 34 CO2 7.333 14.67 1.000 28.37 0.1000E+31 36.20 39.02
 35 CH4 2.000 3.208 1.000 15.63 0.1000E+31 46.47 48.70
Received on Mon Jul 12 2010 - 19:09:37 CEST