The modules in the testbeam simulation

 A realistic simulation of the signals in the TRT prototype has to include not only a detailed model of the prototype but also a simulation of the other elements in the beamline. This is the only way to ensure that effects from material upstream and small effects from the alignment procedure are taken into account. As it was shown in section 5.5 the purity of the beams are so good that the electron and pion data can be assumed to be completely clean samples. For this reason the particle identification devices have not been simulated. An event display of a simulated 20 GeV electron coming down the beamline and bent in the magnetic field is shown in fig. 5.14. The particle continuing in a straight line is an emitted photon and the small wiggle inside the second TRT module a $\delta$ -ray.

  

Figure 5.14: An event display of a simulated 20 GeV electron coming down the beamline and bent in the magnetic field. The particle continuing in a straight line is an emitted photon and the small wiggle inside the second TRT module prototype a $\delta$ -ray. Note the factor 10 difference in the horizontal and vertical scale.