Advanced target concepts for production of radioactive ions and neutrino beams

The 1-20 MW of proton beam power which modern accelerator technology put at our disposal for production of intense secondary beams presents a major technically challenge to the production targets. A conceptual design is presented for a high-power pion production target and collection system, which was originally suggested to be used as the source for the proposed CERN muon-neutrino factory. It will be shown that the major parts of this target could also serve as an efficient spallation neutron source for production of 6He and fission products in the two-step converter-target concept. The heart of the system consists of a free surface Mercury jet with a high axial velocity, which allows the heat to be carried away efficiently from the production region. For the neutrino factory the secondary pions are collected and injected into the pion decay-channel by means of a magnetic horn. For the radioactive ion-beam facility the Hg-jet is surrounded by the high-temperature ISOL production-target. The suggested mechanical layout and technical parameters of the Hg-jet, ISOL target, horn and cooling system are discussed. The critical issues are identified and a description of the R&D program designed to provide experimental proof of the principle as well as providing engineering parameters is given

Palynostratigraphy of the Lower and Middle Pennsylvanian coals of Iowa

The Pennsylvanian System in Iowa includes strata ranging from Morrowan to Virgilian in age. Based primarily on core studies, the palynology of coals has formed the basis for refinement of stratigraphic correlations through the dominantly non-marine Lower and Middle Pennsylvanian sequence, and has permitted formational subdivision of the complex Cherokee Group. The palynological characteristics of the major coals and coal-bearing units are described in detail. The sequence of miospore appearances and extinctions permits close correlation of Iowa coals to coals of the Illinois Basin. In addition, the miospore stratigraphy of Iowa coals corresponds strongly to published zonations for the Upper Carboniferous coal-bearing strata of western Europe and the Soviet Union. In recognition of serious problems that exist in the application of standard Midcontinent Pennsylvanian chronostratigraphic nomenclature to the Iowa section, practical means for distinction of Morrowan, Atokan and Desmoinesian strata are proposed to facilitate regional correlations. The extinction of Schulzospora rara is used to mark the top of the Morrowan Series, and the extinction of Dictyotriletes bireticulaius is considered to indicate the top of the Atokan. 314 species assigned to 111 genera are documented and illustrated, and their observed occurrences in the Iowa section are summarized. Three new genera, Anacanthotriletes, Anafoveosporiies and Dictyomonolites are proposed: the diagnoses of five genera. Apiculatasporites Ibrahim 1933, Reiiculitriletes Madler 1964, Sinuspores Artiiz 1957. Dictyotrileies Naumova ex Potonié and Kremp 1954 and Spackmanites Habib 1966 are emended to reflect new interpretations of their morphology. Thirteen new species are described, and thirteen other new names are proposed to correct or avoid homonymies. Several other genera are reviewed and new combinations proposed

The Role of Diffusion in ISOL Targets for the Production of radioactive Ions Beams

On line isotope separation techniques (ISOL) for production of ion beams of short-lived radionuclides require fast separation of nuclear reaction products from irradiated target materials followed by a transfer into an ion source. As a first step in this transport chain the release of nuclear reaction products from refractory metals has been studied systematically and will be reviewed. High-energy protons (500-1000MeV) produce a large number of radionuclides in irradiated materials via the nuclear reactions spallation, fission and fragmentation. Foils and powder of Re, W, Ta, Hf, Mo, Nb, Zr, Y, Ti and C were irradiated with protons (600-1000MeV) at the Dubna synchrocyclotron and at the CERN PS-booster to produce different nuclear reaction products. The main topic of the paper is the determination of diffusion coefficients of the nuclear reaction products in the target matrix, data evaluation and a systematic interpretation of the data. The influence of the ionic radius of the diffusing species and the lattice type of the host material used as matrix or target on the diffusion will be evaluated from these systematics. Special attention was directed to the release of group I, II and III-elements. Arrhenius plots lead to activation energies of the diffusion process

Plant Biomarker Pattern, Apples grown with various availability of organic nitrogen and with or witout the use of pesticides

In the recent years there has been an increasing focus on the quality and health value of organic plant products compared with conventional products. The use of pesticides and concentrated fertilisers in conventional agriculture implies a risk of effects on plant composition, which may affect health of the consumer (Brandt & Mølgaard, 2001). To determine if organically grown plant food could provide more or less benefits to health than conventional food, a first step is to investigate the differences in the composition and relative concentration of natural compounds in the plant products. In this project apples were grown with two levels of nitrogen availability and with or without the use of pesticides. The apples were screened for changes in the phytochemical composition and concentration. The work is affiliated to the project "Organic food and health" supported by the Danish Research Centre for Organic Farming (DARCOF). Biomarkers and biomarker patterns were presented in plants cultivated with low and high N and with pesticides. One biomarker was related to: • the type of N with and without pesticides • pesticides at high N and type of N without pesticides • pesticides at low and high N One biomarker pattern was related to: • the type of N • the type of N without pesticides • pesticides at low N and type of N without pesticides • pesticides at high N and type of N with pesticide

A Second Generation Radioactive Nuclear Beam Facility at CERN

The proposed Superconducting Proton Linac (SPL) at CERN would be an ideal driver for a proton-driven second-generation Radioactive Nuclear Beam facility. We propose to investigate the feasibility of constructing such a facility at CERN close to the present PS Booster ISOLDE facility. The existing ISOLDE facility would be fed with a 10 micro-amps proton beam from SPL, providing the physics community with a low-intensity experimental area. A second, new facility would be built with target stations deep underground, permitting proton beam intensities of more than 100 micro-amps. The secondary beams can be post-accelerated to 20-100 MeV/u and there will be a storage ring complex and large segmented detectors in the experimental area. Also, benefits from a muon-ion collider or from merging the ions and muons should be investigated. Since the antiproton decelerator would be nearby, the opportunities for antiprotonic radioactive atom studies should be pursued as well