CORSIKA bug and other updates

Dmitry Chirkin UC Berkeley

CORSIKA updates

• Track times are given relative to the shower core arrival to the surface

• F2k and related fixes: track numbers and parent ids (treated by ucr), p->Z1

• All coordinates are given at the observation level (ice surface), track length now exact

• Shower times can now be assigned and coincident showers can be treated (by combining them within a predefined time window)

CORSIKA bug

• CORSIKA version 6.023 and earlier had muon radiative energy losses underestimated by 103. As of version 6.030 this is corrected. Effect on the background calculation is minor.

Nch distributions

• To estimate the differences between different CORSIKA versions and CR spectrum models, and effect of the coincident showers on the background simulation, Nch distributions are compared.

Spectrum index corrections

• results

1st method

2nd method

CORSIKA updates (continued)

• Possible to choose between Wiebel-Sooth and Jorg Horandel published primary spectra. The latter is implemented within the poli-gonato model of the CR energy spectrum. This implementation is now valid up to 50 PeV

Poli-gonato CR spectrum fits

• From J-H

Conclusions

• Many updates to CORSIKA were implemented• CORSIKA bug is corrected in current version

(6.030) and has no effect on the background muon simulation

• Coincident shower events do not significantly affect the background simulation

• Change from Wiebel-Sooth CR spectra to the Jorg Horandel poli-gonato model does affect the background simulation, the change in spectral index is of the order 0.02

Auxiliary slides

• Spectrum correction depth profiles

Spectrum corrections method

• Also my spectrum corrections method was applied

1st method

2nd method