ATIC as a testbed for the ACCESS baseline calorimeter

The Advanced Thin Ionization Calorimeter (ATIC) balloon experiment is designed to measure the spectrum of individual elements from H through Fe up to a total energy >1014 eV. To accomplish this goal, ATIC incorporates a Silicon matrix detector composed of more than 4,000 pixels to measure the incident particle charge in the presence of backscatter background, three plastic scintillator hodoscopes to provide an event trigger as well as a backup measurement of the particle charge and trajectory, a 3/4 interaction length carbon target and a fully active ionization calorimeter composed of 22 radiation lengths of Bismuth Germanate (BGO) crystals. This detector complement is very similar to the baseline calorimeter for the Advanced Cosmic Ray Composition Experiment for the Space Station, ACCESS. The ATIC flights can be used to evaluate such a calorimeter in the cosmic ray “beam.” ATIC integration is currently underway with a first flight expected during 1999. This talk will discuss ATIC as it applies to ACCESS.