Development of a sub-glacial array of radio antennas for the detection of the flux of GZK neutrinos

us exclusive information about ultra-high energy processes in the Universe. These particles,

which hold energies above 10^16 eV, interact very rarely. Therefore, detectors of

several gigatons of matter are needed to discover them. The ARA detector is planned

and currently being constructed at the South Pole. It is designed to use the Askaryan

effect, the emission of radio waves from neutrino induced cascades in the South Pole ice,

to detect neutrino interactions. With antennas distributed in 37 stations in the ice, such

interactions can be observed in a volume of several hundred cubic kilometers. Currently

2 ARA stations have been deployed in the ice and are taking data since the beginning

of the year 2013.

The first part of this thesis summarizes the current theories concerning the GZK mechanism

and the Askaryan effect to explain the interest in GZK neutrinos and in the used

detection method.

In the second part the ARA detector is described and calibrations of different detector

parts are presented. In this work, the digitization chips have been calibrated concerning

their timing precision and signal amplitude. In this way a timing precision of 100 ps

between antennas could be achieved. Furthermore, the geometry of the antenna clusters

is determined by cuts based on external signals to allow for a proper radio vertex reconstruction.

In the third part of the thesis the development of methods to distinguish radio signals

from thermal noise are presented. Moreover, a reconstruction method, developed to determine

the position of radio sources, is described. With only two stations operational

a discovery of GZK neutrinos is not expected and in fact no signal candidate has been

found in the analysis of the data. A neutrino

ux limit is calculated. This limit is not

competitive yet with the current best limits, but very promising for the full ARA detector.

The work shows that after completion this detector is expected to be capable of a

neutrino discovery.