Introduction
Cosmic rays are high-energy particle nuclei which routinely enter our
atmosphere from all directions in space. Cosmic rays can have
energies orders of magnitude higher than the energies created on Earth
in our particle accelerators. Many cosmic rays are from outside
our solar system, and some are even from outside our galaxy. By
studying cosmic rays, we gain insight into the workings of our universe.
There is much that remains unknown about these cosmic rays. For
example, what is their composition? We know they can be as light
as protons or as heavy as iron nuclei (or anything inbetween) but what
are they most of the time? Also, what is their origin? At
very low energies, cosmic rays come from the sun, However, cosmic
rays in the medium to high energy range are not well understood.
Where could they be created, and what processes accelerate them to
such high energies? Another question arises when examining an
energy spectrum of cosmic rays. At an energy of about 3 PeV
(10^15 eV), the slope of the cosmic rays' spectrum suddenly
steepens. What causes this change?
There are two detector arrays located at Earth's geographic South Pole
used to study cosmic rays. The first is the South Pole Air Shower
Experiment (SPASE), located on the surface of the Antarctic ice sheet.
SPASE is a scintillator array that detects charged particles such
as electrons and muons, both of which are produced by the cosmic ray/air
molecule collisional debris. The second detector is the Antarctic
Muon and Neutrino Detector Array (AMANDA). Buried nearly two
kilometers under the surface, AMANDA detects Cherenkov radiation from
muons traveling through the ice, including those muons from the air
shower debris. By combining the data from SPASE and AMANDA, a
great deal of information regarding a cosmic ray's mass and energy can
be revealed, ultimately leading to an understanding of the origin of
these mysterious particles.
Previous analyses of cosmic ray composition with AMANDA/SPASE used data
from the years 1997 and 1998 taken by AMANDA-B10, a previous version of
the detector. AMANDA-B10, a ten-string array, consisted of only
~300 detector modules. In the year 2000, AMANDA was expanded to
AMANDA-II, a 19-sring array with nearly 700 detector modules. The
AMANDA data set from 2002 is the first set for which there is also
easily accessible data from SPASE. This 2002 analysis, using a
larger detector than the previous studies, should provide interesting
results.
Studying cosmic ray composition using AMANDA/SPASE is in fact quite a
large project, requiring much more time than a 10-week summer program
allows. Therefore, my work this summer was on the initial stages
of analyzing the 2002 data set from AMANDA. These stages are
described below.
The Good Stuff
Here is information regarding my work this summer. These pages
are listed more or less "chronologically," so go through them one after
another for a summary of my summer.
Useful and Fun Links
The AMANDA site at UW-Madison
The SPASE-AMANDA site
at the Bartol Institute
Los Alamos National Lab Pre-Print
archive
NASA
Astrophysics Data Service
UNIX tutorial
Web page basics
Kath Rawlins, my wonderful
mentor
The Lake Afton Public
Observatory
Amanda's Very Own Page
Final Thoughts
The Antarctic Muon and Neutrino Detector Array, AMANDA.
Gee... what a nice name. It's like having my very own neutrino
telescope...
Who could ask for anything more? 
-- created July 2, 2003
-- updated August 15, 2003
