Accelerator Data Needed for the Interpretation of High Energy Cosmic Rays<br> 
Lawrence W. Jones<br> 
University of Michigan <br><br> 
Abstract<br> 

The study of cosmic rays with energies above 1000 TeV is important as
it is in this energy range that there are apparently changes in
their origin, acceleration, and galactic confinement.  However,
because of their low flux, we are totally dependent on ground-level
measurements (e.g. extensive air showers) for their study.  The
mass numbers and energies of the primary cosmic rays must then be
determined using Monte Carlos to simulate the primary interactions
and subsequent atmospheric cascades.  The problem is that the
existing Monte Carlos are primarily based on sub-TeV fixed-target
data,and there are great uncertainties and confusions.  This talk
will review this subject and then discuss the hadron collider data
needed to resolve these problems, concluding with a summary of
recent European conferences related to these topics.