The EDDA-Detector at the Cooler-Synchrotron COSY/J\"ulich has been operated with an internal CH$_2$ fiber target to measure proton-proton elastic scattering differential cross sections. For the data analysis knowledge of beam parameters, like position, width and angle, are indispensable. We have developed a method to obtain these values with high precision from the azimuthal and polar angles of the ejectiles only, by exploiting the coplanarity of the two final state protons with the beam and the kinematic correlation. The formalism is described and results for beam parameters obtained during beam acceleration are given.

Thin polypropylene fibers have been used for internal experiments in storage rings as an option for hydrogen targets. The change of the hydrogen content due to the radiation dose applied by the circulating proton beam has been investigated in the range 1 × 106–2 × 108 Gy at beam momenta of 1.5–3 GeV/c by comparing the elastic pp-scattering yield to that from inelastic p-carbon reactions. It is found that the loss of hydrogen as a function of applied dose receives contributions from a fast and a slow component.

Several available codes for hadronic event generation and shower simulation are discussed and their predictions are compared to experimental data in order to obtain a satisfactory description of hadronic processes in Monte Carlo studies of detector systems for medium energy experiments. The most reasonable description is found for the intranuclear-cascade (INC) model of Bertini which employs microscopic description of the INC, taking into account elastic and inelastic pion-nucleon and nucleon-nucleon scattering. The isobar model of Sternheimer and Lindenbaum is used to simulate the inelastic elementary collisions inside the nucleus via formation and decay of the Delta(33)-resonance which, however, limits the model at higher energies.To overcome this limitation, the INC model has been extended by using the resonance model of the HADRIN code, considering all resonances in elementary collisions contributing more than 2% to the total cross-section up to kinetic energies of 5 GeV. In addition, angular distributions based on phase shift analysis are used for elastic nucleon-nucleon as well as elastic and charge exchange pion-nucleon scattering. Also kaons and antinucleons can be treated as projectiles. Good agreement with experimental data is found predominantly for lower projectile energies, i.e. in the regime of the Bertini code. The original as well as the extended Bertini model have been implemented as shower codes into the high energy detector simulation package GEANT-3.14, allowing now its use also in full Monte Carlo studies of detector systems at intermediate energies. The GEANT-3.14 here have been used mainly for its powerful geometry and analysing packages due to the complex EDDA detector system. (C) 2002 Elsevier Science B.V. All rights reserved.

Scintillating fibers of type Bicron BCF-12 with 2 × 2 mm2 cross section, up to 600 mm length, and PMMA cladding have been tested, in conjunction with the multi-channel photomultiplier Hamamatsu R 4760, with minimum ionizing electrons. The impact of cladding, extramural absorbers and/or wrapping on the light attenuation and photoelectron yield is studied in detail. Fibers have been circularly bent with radii of 171 mm and arranged in two layers to bundles forming granulated scintillator rings. Their performance in the EDDA experiment at COSY for detection of high energy protons revealed typically more than 9 (6) photoelectrons per fiber from bundles with (without) mirror on the rear side, guaranteeing detection efficiencies >99% and full compatibility with corresponding solid scintillator rings. The time resolution of 3.4 ns FWHM per fiber read out is essentially due to the R 4760.

For the EDDA experiment at COSY, the response of the small, linear focused photomultipliers Hamamatsu R 1450 and R 1355 has been studied with fast light pulses generating yields up to 2 × 103 photoelectrons/cm2 or peak currents of 24 mA. Linearity was obtained with a tapered bleeder chain at a tolerable loss of gain. The serial test of altogether 140 photomultipliers revealed the close correlation between single electron and amplitude resolution. The influence of the photoelectron statistics on this correlation is discussed.

A novel detector design of overlapping plastic scintillator elements in cylindrical geometry has been developed for detection of low multiplicity events of fast protons and other light charged particles: each particle traversing the detector from the axis outwards will produce light in several elements. The relative amounts of energy deposited in those elements allow one to interpolate on the particle trajectory beyond the resolution given by the granularity. The detector covers the angular range 10° ≤ Θlab ≤ 72° and 0° ≤ ϕ ≤ 360° with an inner layer of scintillator bars of triangular cross section and an outer layer of rings. The material is BC408. Tests with minimum ionizing electron beams show that spatial resolutions of ΔΘlab ≈ 1.5° and Δϕ12 ≈ 1.5° (FWHM) can be obtained for electrons or proton pairs with energies in the GeV range. In the EDDA experiment the ultimate spatial resolution is then determined by the size of the interaction area rather than by the intrinsic pulse height resolution of the detector.

The EDDA experiment is designed to study p + p excitation functions with high energy resolution and narrow step size in the kinetic energy range from 250 MeV to 2500 MeV at the Cooler Synchrotron COSY. Measurements during the accelertion phase in conjunction with internal targets will allow to achieve a fast and precise energy variation. Prototypes of the detector elements and the fiber target have been extensively tested with proton and electron beams; the detector performance and trigger efficiency have been studied in Monte Carlo simulations. In this contribution, results concerning detector design, prototype studies, Monte Carlo simulations and the anticipated detector resolutions will be reported.

Some results of Crapo [1, 2] on the Möbius function of a finite partially ordered set are treated in a slightly generalized context. Another proof is given of Rota's cross-cut theorem [3]. Furthermore, there the possible values of the Möbius function are determined for a finite lattice L with an n-element cross-cut (Satz 5): −n−12n+14≦μ(L)≦n−12n+14+1

Gegenüber der Benutzung von wäßrigen Lösungen ergeben sich bei der Verwendung von biologischen Flüssigkeiten wie Serum, Plasma und Vollblut bei dem Gebrauch derPreglschen Präzisionswägepipette gewisse methodische Schwierigkeiten. Es sind dies die Blutgerinnung, die Temperaturangabe bei Messung des nativen Vollblutes, das starke Haftvermögen an der Glaswand und die leicht eintretende Luftbläschenbildung. Trotzdem wird eine Genauigkeit erreicht, die für die Serumdichte ± 0,0001, für die Vollblutdichte ± 0,0004 und für die Blutzelldichte ± 0,0006 beträgt. Aus einem großen Untersuchungsmaterial konnten folgende Mittelwerte bestimmt werden: Serumdichte (Männer) 1,0232, (Frauen) 1,0233; Vollblutdichte (Männer) 1,0527, (Frauen) 1,0495. Eine Nachuntersuchung der Abhängigkeit der Eiweißkonzentration von der Serumdichte ergab, daß die Werte vonvan Slyke5 mit einem durchgehenden methodischen Fehler behaftet sind. Das empirisch aufgestellte Nomogramm vonPhillips und Mitarbeitern, das einen Zusammenhang zwischen den Größen der Serum- und Vollblutdichte sowie des Hämatokrits bringt, wurde auf Grund unsres gewonnenen Untersuchungsmaterials statistisch berechnet. Es unterscheidet sich wesentlich durch die lineare Korrelation, die Angaben der statistischen Daten und die Fehlerbreite. Ferner konnte gezeigt werden, daß durch die Messung der Dichte des Serums, des Vollblutes und der Blutzellen sowie durch die Bestimmung der Blutzellen-Blutwasser-Relation, dem Hämatokrit, tiefe Einblicke in die Hämodynamik des Kapillargebietes ermöglicht werden konnten. So war es möglich, Gewebswasserverschiebungen sowohl im System Gewebe-Blutwasser, als auch solche zwischen Blutwasser und Blutzellen unter bestimmten Bedingungen aufzuzeigen.

Durch Einfluß von Permease (Sanabo, 100 Viscositätseinheiten i.v.) tritt am Menschen kein verstärkter Kongorotschwund aus der Blutbahnein.