SENECA is a code for simulating the shower of particles created by an ultrahigh energy cosmic ray hitting the Earth’s atmosphere which was developed at NYU by H. Drescher and G. Farrar, supported by NASA. Thanks to a new hybrid approach, SENECA is about 40 times faster than CORSIKA and is realistic on an event-by-event basis. Tools for simulating detector response and studying event reconstruction are provided.

Graduate student Jeff Allen has ported SENECA to the “off-line analysis” system of the Pierre Auger Observatory. Thanks to SENECA’s structure, the process called “thinning”, whereby only a subset of the 10^10 particles in the shower are followed in detail, can be implemented without introducing artifacts as in conventional implementations of thinning.