[en] Since the pioneering experiment of R. Davis et al., which started neutrino astronomy by measuring the solar neutrinos via the inverse beta decay reaction on ³⁷Cl, all solar neutrino experiments find a considerably lower flux than expected by standard solar models. This finding is generally called the solar neutrino problem. Many attempts have been made to explain this result by altering the solar models, or assuming different nuclear cross sections for fusion processes assumed to be the energy sources in the sun. There have been performed numerous experiments recently to investigate the different possibilities to explain the solar neutrino problem. These experiments covered solar physics with helioseismology, nuclear cross section measurements, and solar neutrino experiments. Up to now no convincing explanation based on 'standard' physics was suggested. However, assuming non-standard neutrino properties, i.e. neutrino masses and mixing as expected in most extensions of the standard theory of elementary particle physics, natural solutions for the solar neutrino problem can be found. It appears that with this newly invented neutrino astronomy fundamental information on astrophysics as well as elementary particle physics are tested uniquely. In this contribution an attempt is made to review the situation of the neutrino astronomy for solar neutrino spectroscopy and discuss the future prospects in this field

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[en] The paper reviews neutrino mixing and neutrino oscillations, in elementary particle physics. Neutrino mixing; search for neutrino mass; consequences of neutrino mixing; neutrino oscillations; and neutrino oscillation experiments at nuclear power reactors; are all discussed. (U.K.)

[en] At a time when industry is gathering itself for a programme of construction for oil tankers there has never been a better time to take stock of the available experience and of the associated classification requirements regarding structural strength. Recent events have highlighted that accountability for manufacture and the standards employed in ship construction cannot be ignored as a possibility, regardless of how far downstream an incident occurs. The adequacy of a ship can, of course, be influenced by many factors which can include aspects from the basic concept design to the operational controls and management systems employed. The purpose of this paper is to provide an awareness of how certain elements can influence the accident risk and to indicate how Lloyd's Register is addressing these matters. The following aspects relating predominantly to the hull of the ship are therefore discussed:- future Legislation; rule development; structural development; optimisation of structural arrangements; operational considerations; ageing of oil tankers; summary and conclusions. (Author)

[en] Radiation detectors based on low temperature calorimetry, non equilibrium phonons and quasiparticle trapping in superconductors were developed. To measure the radiation induced rise in temperature in a 280 g sapphire calorimeter a superconducting Ir phase transition thermometer controlled by a DC-SQUID was used leading to a relative accuracy of 54 nK. With this calorimeter an energy resolution of 1.2% for 5.9 MeV α-particles was achieved. To detect the radiation induced phonons in a Si single crystal and for the measurement of in Sn radiation induced quasiparticles Al/Al₂O₃/Al junctions where used. For non equilibrium phonon detection and a weak thermal contact of the absorber to the cooling device the signal dependence on the distance between the phonon detecting tunneldiode and the point of radiation absorption was investigated. Using quasiparticle trapping from Sn to Al for 5.89 keV x-rays an energy resolution of 60 eV was achieved with an x-ray sensitive area of 975 x 150 μm² as well as a position sensitivity of 5 μm in the longitudinal direction

[en] Neutron Activation Analysis has emerged to be an analytical method sensitive enough to detect fg/g traces of unstable primordial nuclides in complex matrices. Especially low count rate experiments in the field of solar neutrino physics and dark matter search can profit from the detection capabilities of this method which had been unattained so far. This gain in sensitivity has been achieved by combining neutron activation, radiochemical separation methods, and efficient low level counting systems at the new underground laboratory of the accelerator laboratory in Garching. Recent improvements which have been made in the purification and analysis of the liquid scintillator, as foreseen for the solar neutrino experiment BOREXINO, are being presented as an example in this paper

[en] Limits for the neutrino decay ν_H → ν_L+γ, where ν_H and ν_L are assumed to be massive neutrinos with m_νH > m_νL, are presented using data from the Solar Maximum Mission satellite taken in coincidence with the detected neutrino burst from SN 1987A. These limits are essentially independent of supernova models and are τ/manti ν_e > 8.3x10¹⁴ s/eV and τ/m_νμ,τ > 3.3x10¹⁴ s/eV for a thermal spectrum at a temperature Tanti ν_e = 3 MeV. (orig.)

[en] Neutrino oscillations occur if neutrinos have masses and if they mix among each other. This phenomenon would be in close analogy to the experimentally observed mixing in the quark sector. Neutrino oscillations are therefore very interesting in the context of elementary particle physics. Further, neutrino oscillation in matter is probably the reason for the observed deficit of the solar neutrino flux. As an interference effect, the search for neutrino oscillations is the only way to investigate even very small differences of neutrino masses. In this article, after an introduction of the theoretical background concerning massive neutrinos, we describe important experiments which have been performed in this field. Experiments looking for neutrino oscillations have been carried out using accelerators, nuclear power plants, cosmic rays and the sun as neutrino sources. Also, the observed neutrino burst of supernova 1987a has implications for the oscillation parameter. In the last chapter we show the interesting link of neutrino oscillations to related phenomena, such as neutrino decay and the possible existence of a 17 keV neutrino, coupled weakly to the electron. (author)

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No abstract available