Haverah Park was a research site operated by the Physics Department
of the University of Leeds. For 20 years it was home to one of the largest
extensive air shower arrays in the world
with an area of 12 square kilometres. The array was made up of
water Cerenkov detectors housed in wooden huts
and operated until 1987 when it was switched off.
During its lifetime many 1000's of extensive air showers were recorded
including four exceptional ones of such size that the cosmic rays
that generated them must have had energies greater than
1020 eV. These particles are the
highest energy form of radiation known to exist
anywhere in the universe and their origin is one of science's greatest mysteries.
For several years these findings were somewhat controversial being in disagreement with other experiments and theories which denied the possibility of such energetic cosmic rays. However in 1993 an experiment in Utah, called Fly's Eye reported the detection of a cosmic ray of energy 3x1020 eV. Finally the existence of these remarkable particles was confirmed. Subsequently the Japanese experiment at Akeno has reported a further 6 events with energy >1020 eV.
After the large array was decommissioned a smaller array called
GREX was built to look for sources of high
energy (>1014 eV) gamma rays. This array operated in conjunction
with several other experiments such as the CERES air-Cerenkov detector and
the PLASTEX particle tracking experiment. Finally in 1993 Haverah Park was
That's not the end of the story however. After the Fly's Eye group
confirmed the existence of the very high energy cosmic rays detected
at Haverah Park interest in this area of astrophysics grew. Construction
of two giant air shower arrays covering thousands
of square kilometres began in March 1999. The two arrays will be known
the Pierre Auger Observatory in honour of the
man who first discovered extensive air showers. Many aspects of the
design of the array have been influenced by scientists from Leeds and
in particular the detector design is based on the water Cerenkov tank
utilised so successfully at Haverah Park.
Haverah Park is situated on farmland on the North Yorkshire Moors, UK. It is 17 miles from the University of Leeds, and 3 miles from the nearest town, Harrogate.