The HERA Storage ring

HERA-B is one of the four high energy experiments which are located at the HERA^2.1 collider at DESY^2.2 in the North-West of Hamburg. It accelerates positrons or electrons to 27.5 GeV and protons to 920 GeV and has a circumference of 6.3 km.

The two beams are colliding at two interactions zones ( Hall North and Hall South), where the experiments H1 and Zeus are placed (see Fig. 2.1). The physical programs of these experiments include: measuring of the proton structure, studies of the hadronic final state including jet physics, diffractive scattering in deep inelastic scattering and photo production of jets.

In the east hall of HERA a fixed target experiment HERMES is situated. The experiment uses longitudinally polarized positrons and has an internal polarized gas target. HERMES investigates the spin structure of the nucleon.

The fourth experiment is HERA-B and it is located in the experimental hall West. HERA-B uses only the proton beam, by introducing thin target wires in the halo of the proton beam interactions of the protons with the target wires are produced. This setup allows an operation at high interaction rates without disturbing the operation of the other experiments. The physical program of the HERA-B experiment is described in chapter 1.

Figure 2.1: The layout of the accelerators and experiments situated at DESY in Hamburg. Left: Overview over the complete facility. Right:The pre-accelerators DESY-II and PETRA and the Hall West where the HERA-B is placed.