A holographic streamer chamber for relativistic nucleus-nucleus collision experiments

One of the experimental difficulties in handling the events from relativistic nucleus-nucleus collisions is the extremely high multiplicity of these events. In a collision of an 160 ion with an energy of 200 GeV/A on 197Au for a minimum bias trigger the total multiplicity is expected to be 250 and can be up to 500 for a central collision. In addition to the primary produced particles secondary intractions take place and also a large number of knock-on electrons, so called delta-rays, will be created. Therefore, not only a precise position measurement, and time resolution is needed, but also a good two track separation and pattern recognition capability is desirable. An optical track detector like a conventional streamer chamber at atmospheric pressure and with film recording may meet the mentioned requirements, but there are still doubts that the detection efficiency for neutral strange particle decays will be high enough. These decays are expected to be an indication for the existence of the quark gluon plasma. A streamer chamber operation is described which improves the resolution and detection efficiency for neutral strange particles significantly.