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In this article we describe the experimental results of a methane hydrate moderator as well as as mesitylene moderator operated at a temperature around 20K at the JESSICA (Jülich Experimental Spallation Target Set-up In COSY Area) experiment at the Jülich cooler synchrotron COSY. For the first time the cold neutron spectrum of a methane hydrate moderator was experimentally investigated. A comparison with a solid methane and an ice moderator at T = 20 K will be shown. MCNPX simulations with new developed S(α,β) scattering kernels will be compared with experimental data. The applicability of mesitylene and methane hydrate as cold moderators at spallation neutron sources will be discussed. [ABSTRACT FROM AUTHOR]

In this article measured time-of-flight spectra and energy spectra of a water moderator operated at various temperatures between 20K and room temperature are described. These data are used to validate generated and processed neutron scattering law data. It was possible to simulate the leakage spectrum of a water moderator at cryogenic temperatures and compare it with experimental results. [ABSTRACT FROM AUTHOR]

A recent renascent interest in energetic proton-induced production of neutrons originates largely from the inception of projects for target stations of intense spallation neutron sources, like the planned European Spallation Source (ESS), accelerator-driven nuclear reactors, nuclear waste transmutation, and also from the application for radioactive beams. In the framework of such a neutron production, of major importance is the search for ways for the most efficient conversion of the primary beam energy into neutron production. Although the issue has been quite successfully addressed experimentally by varying the incident proton energy for various target materials and by covering a huge collection of different target geometries --providing an exhaustive matrix of benchmark data-- the ultimate challenge is to increase the predictive power of transport codes currently on the market. To scrutinize these codes, calculations of reaction cross-sections, hadronic interaction lengths, average neutron multiplicities, neutron multiplicity and energy distributions, and the development of hadronic showers are confronted with recent experimental data of the NESSI collaboration. Program packages like HERMES, LCS or MCNPX master the prevision of reaction cross-sections, hadronic interaction lengths, averaged neutron multiplicities and neutron multiplicity distributions in thick and thin targets for a wide spectrum of incident proton energies, geometrical shapes and materials of the target generally within less than 10% deviation, while production cross-section measurements for light charged particles on thin targets point out that appreciable distinctions exist within these models. [ABSTRACT FROM AUTHOR]

Presents papers on cell activation and astroglia stimulation, which were presented at the Fourth International Symposium on NeuroVirology and at the Tenth Conference on Neuroscience of HIV Infection. HTLV-I transcription during cellular differentiation and activation in bone marrow, peripheral blood and brain; Association of astrocyte protease-activated receptor stimulation with Gi linked release of MCP-1 and MMP-9; Activation of the blood brain barrier; Intracellular calcium dysregulation in cultured rat cortical astrocytes.