Reconstruction

The algorithm used to reconstruct the position of the particle proceeds by scanning for the strip with the highest signal, provided that signal is greater than 3:1. Its highest neighbour is taken, provided its signal is greater than 2:1. Then the position is determined by $\eta=R/(L+R)$ where L,R are the left and right most strips.

This algorithm works well for small angles but is quite poor at large angles. Consequently, for crossing angles greater than 15^o, we have used an algorithm as described by the DELPHI collaboration [3]. All strips greater than 2:1 about the highest signal are taken and the position is the midpoint between the first and last channels of the cluster, corrected with

$$\omega=\bigl[min(S_{first},\bar S)-min(S_{last},\bar S)\bigr]/(2\bar S)$$

where $\bar S$ is the average pulse-height of all channels in between.

The effects that each of the ingredients in our simulation has on the calculated resolution is shown in Fig. . Turning on diffusion improves the resolution at small angles. The Lorenz angle shifts the distribution, while the Landau distribution degrades the resolution, particularly at large angles.