The H1 experiment at HERA 1988-
Quite early I was engaged in the discussions and preparation for the
ep collider HERA. In 1988 we obtained the formal support from the Research
Council to paticipate in the H1 experiment.
H1 is a magnetic detector with a central tracking devise surrounded
by a liquid Argon calorimeter and an instrumented return yoke for
back-up calorimetry and muon detection. Since the centre-of mass is
moving in the direction of the proton, special care has to be taken
in this direction, the so-called forward direction. Therefore a
separate muon spectrometer is being installed in this region. The
Lund group was, together with a group from the University of Manchester,
the responsible for the construction of this detector. It consists of
a toroid magnet providing a field of 1.5 Tesla over a distance of
1.2 metres. In front of and behind the magnet there are three double
layers of large drift chamber planes to determine the polar and
azimuthal angles of the tracks. Good space resolution is necessary
to achieve good momentum resolution and linking between the track
segments in the muon spectrometer and the central tracking system.
A Monte-Carlo study was performed inorder to find out how of the
background contributions from decaying pions and kaons as well as
punch-throughs and sneak-throughs of hadrons could be separated from
prompt muons. This study gave the basic information on how a special
muon trigger for the forward system could be constructed. The trigger
system was developed together with new collaborators from the University
of Birmingham. The analogue logic for this trigger has been developed
in Lund. It is implemented and working in the detector since several
years.
In Lund we have also built a radiation monitor system for the
silicon-strip vertex detector in H1 which includes a read out system
based on a 10 MHz FADC and a special CPU for pulse analysis. Also the
software for the data aquisition and the monitoring has been developed
by us. A prototype was in operation during 1994 and worked without
problems. The full number of 12 radiation monitors was installed early
1995 together with an updated version of the read out system and has
since then been operating.