Cluster size determination using shadowgraphy measurements

Cluster-jet beams offer a wide variety of possible applications. The advantages of an internal and windowless cluster-jet target make it suitable for many experiments. It is important to know all the properties of the cluster-jet to prepare it for the desired conditions of the respective experiments. An essential property is the size of the clusters and their size distribution. To investigate the size of the clusters shadowgraphy measurements are performed. This article provides an overview of the shadowgraphy method and presents first results of these analyses using hydrogen clusters. These show an average cluster size of a few micrometers, which will also be of high interest, besides the here shown laser cluster interaction, for other installations using cluster beams

The Münster cluster-jet target for the future P̅ANDA experiment

For high precision storage ring experiments as the future P̅ANDA experiment, very sophisticated internal targets have to be used. For this purpose, a state-of-the-art cluster-jet target was developed at the University Münster. Basically, hydrogen is cooled to cryogenic temperatures and pressed through a specially shaped Laval nozzle to form a cluster-jet expanding into vacuum. Due to the stability and large mass of the clusters, a practically undisturbed flight path in vacuum of above 5 m is possible, leading to manifold possible applications, including the interaction with a storage ring beam at a distance of 2.25 m as desired for the P̅ANDA experiment. With a first prototype target, the “proof-of-principle” was delivered, and after first improvements the world record in target thickness in such large distance to the nozzle was measured. Based on this work, the final P̅ANDA cluster-jet target was developed and built up, and is presented in this article

Hyperon signatures in the PANDA experiment at FAIR

We present a detailed simulation study of the signatures from the sequential decays of the triple-strange pbar p -> Ω+Ω- -> K+ΛbarK- Λ -> K+pbarπ+K-pπ- process in the PANDA central tracking system with focus on hit patterns and precise time measurement. We present a systematic approach for studying physics channels at the detector level and develop input criteria for tracking algorithms and trigger lines. Finally, we study the beam momentum dependence on the reconstruction efficiency for the PANDA detector