Speaker
Description
Summary
Starting from the source, through the cavities, to the target and into the spectrometers the electrons at MESA/MAGIX do not have to pass any windows. Just before entering the detection-system one barrier has to be passed, which is unfortunate, but essential to seperate the vacuum in the spectrometers from the counting-gas inside the detector.
For the track-reconstruction of low energy electrons (< 105 MeV) every bit of material is crucial, as the best achievable resolution is lowered by multiple scattering in traversed material. The classic approach for TPCs is to homogenise the drift field by surrounding the area with a field-cage, consisting of copper and kapton. To restrict the material barrier to an absolute minimum, we want to get rid of the field-cage on the entrance face of the detector. In this contribution new ideas on how to accomplish this, without distorting the electrical field are presented.
