Design of a detector to study S=−2$S = - 2$ baryon interactions induced by stopped antiproton annihilation

Stopped antiproton annihilation can initiate an effcient chain of reactions to produce Ξ hyperons in recoil free kinematics, suitable for further investigations of ΞN interactions. Four delayed decays and presence of eight charged particles in the final state provide a clean reaction signature and allow for usage of a non-magnetic detection system. With the low energy phase space cooled antiproton beam from ELENA at the CERN AD or future FLAIR facility the realisation of this experiment would become possible. In this article the foreseen detector setup and the experimental program will be presented.

Road to the stars: Relativistic Rocket

This book is an attempt to look at relativistic flight from the point of view of a physicist. According to the principle of reaction-propulsion, the only ‘fuel’ suitable for multi-ton relativistic rockets is antimatter. Propulsion methods, relying on thrust by products of annihilation such as photon rocket (electron-positron annihilation) and meson rocket (proton-antiproton annihilation), are revised accounting for annihilation cross-section. The proposed propulsion system includes reactor and accelerators that form efflux of relativistic ions. Shift to relativistic efflux means transition to higher propulsion efficiency: the efflux beam consists mostly of energy. The rocket equation is derived and numerical calculations for various launching masses are performed. Kinematic approach to estimate effectiveness of relativistic rocket maneuvering is considered. Computer simulation of some curvilinear trajectories is performed. Limiting factors are discussed in Chapter 3. Thermodynamics requires engine cooling. In space, it can be made by means of radiation only. The radiator mass is estimated as a function of efflux power. Space is not emptiness but comprises gas and dust. Despite its rarefaction (n ~ 0.3 cm^-3 ) this gas forms a flow of relativistic ions/atoms bombarding the rocket with the intensity N = nv ~ 10^9 cm^-2s^-1 at v ~ 0.5c, where v is the rocket velocity. Kinetic energy of ions/atoms is 1 GeV, which is hard radiation with the dosage comparable to that inside nuclear reactors. Another danger is relativistic dust. A frontal shield with magnetic and material shielding is considered. The foreseen antimatter ‘fuel’ is antyhydrogen. Due to inherent diamagnetism of antihydrogen, it can be stored in a container with a thin magnetic barrier induced by superconducting loops with alternate direction of current. Modelling of various container geometries is performed. Recommendations are made to find a solution to the vapors problem.