[en] Parity violation in nuclear forces was found by measuring the circular polarization P of γ-rays emitted by unpolarized sources. The analyzing efficiency of the Compton backward polarimeter was calculated by Monte-Carlo method and measured by circular polarization correlation of annihilation quanta to be (4.7 +- 0.3)% resp. (4.5 +- 0.5)%. The earlier Bonn result of 482 keV ¹⁸¹Ta γ-polarization of -(28 +- 6)10^-6 was found to be incorrect and simulated by a 2 per thousand asymmetry of magnet current. The final results in agreement with other authors are P = -(5.8 +- 8.1)10^-6 482 keV, ¹⁸¹Ta; P = -(1.9 +- 0.6)10^-3 501 keV, ¹⁸⁰Hf. See also Z. Phys. 269(1974)421. (BJ)

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[en] The cyclotron trap is a device to increase the stop density of negatively charged particles. Its working principle is to wind up the range of a stopping particle in a weak focusing magnetic field. Its main application in the past was the spectroscopy of exotic atoms. A modern application is the production of low energy muon or antiproton beams. (orig.)

[en] A new technique to stop negatively charged particles inside a cyclotron field is motivated and presented. Its ability to produce a sufficient number of antiprotonic atoms is demonstrated with experimental results at target gas pressures previously not attainable. Thus the knowledge of the cascade process in antiprotonic hydrogen could be extended considerably and the strong interaction parameters in this system could be measured with good precision. It could also be shown that antiprotonic noble gas atoms up to krypton are ionized completely. Moreover, the possibility to extract slow antiprotons out of the center of the cyclotron trap is discussed shortly. (orig.)

[en] A review about the present situation in the field of exotic atoms is given. For the different areas in this field, the achievements are described and the necessary future developments are mentioned. Especially the possibility of measuring kaonic hydrogen X-rays at KAON is discussed. (orig.)

[en] Precise determination of the four coupling constants describing the parity-odd neutral current interaction between muon and nucleons would provide a critical test of the standard model. The directional correlation between the photon emitted in the transition between 2S- and 1S-states and the decay electron provides a suitable observable. The two isotopes of boron constitute a unique system for a complete determination of the coupling constants. Completeness requires that the hyperfine components of the initial or final state of the photon transition be distinguished. An elegant method of measuring the directional correlations in the hyperfine components of the final state is the Fourier analysis of the muon spin precession in correlation with the emitted photon radiation. The purpose of this paper is to derive the relationship between the directional correlations and the coupling constants, determine optimal energy and angular intervals for a measurement, and discuss the experimental issues which must be resolved in preparation of an experiment. (orig.)