This paper describes the optimization of process conditions for making porous anodic alumina as a catalyst support in monolithic microreactors. The basic process involves direct current anodization of 1100 alloy aluminum in oxalic acid. Electrolyte concentration, temperature, and anodization potential are optimized with respect to oxidation efficiency and pore density via a Box-Behnken experimental design to the values of 0.6 M, 18degreesC, and 30 V respectively. The effects of subsequent hydrothermal-thermal treatment on the surface area enhancement and surface morphology of the porous oxide are also investigated and optimized. The resulting films are employed in the fabrication of active catalytic aluminum-alumina microreactors for the decomposition of ammonia to hydrogen and nitrogen. (C) 2004 Elsevier Inc. All rights reserved.

Using data collected by the HERA-B experiment, we have measured the fraction of J/psi's produced via radiative chi(c) decays in interactions of 920 GeV protons with carbon and titanium targets. We obtained R-chic = 0.32 +/- 0.06(stat) +/- 0.04(sys) for the fraction of J/psi from chi(c) decays averaged over proton-carbon and proton-titanium collisions. This result is in agreement with previous measurements and is compared with theoretical predictions. (C) 2003 Published by Elsevier Science B.V.

Using the HERA B detector, the bb production cross section has been measured in 920 GeV proton collisions on carbon and titanium targets. The bb production was tagged via inclusive bottom quark decays into J/ψ by exploiting the longitudinal separation of J/ψ → l + l − decay vertices from the primary proton-nucleus interaction. Both e + e − and µ + µ − channels have been reconstructed and the combined analysis yields the cross section σ ( bb ) = 32 +14 − 12 (stat) +6 − 7 (sys) nb / nucleon.

The HERA-B experiment is a forward magnetic spectrometer with good particle identification for hadrons and leptons designed to study violation of CP symmetry in the neutral B meson system. The silicon vertex detector operates in a high-rate environment similar to the ones expected at LHC. In this paper we report on our R&D on strip detector design, frontend ASICs, mechanical and thermal engineering, low-mass RF shielding of the HERA proton beam and on the status of our reconstruction software. First experiences with last year's installation are discussed.

The design of the double-sided microstrip detectors for the HERA-B experiment at DESY is discussed, in particular with respect to the strong requirements imposed by the high radiation environment and by the challenging mechanical construction. The detectors are tested with an infrared laser setup and first results from operation in the experiment in 1997 are presented.

This paper presents results of a non-uniform irradiation of a single-sided ac-coupledp-on-n siliconstrip detector integrated ona HERA-B detector module. The fluences received by different areas of the detector wafer ranged from less than2 × 1013 MIP/cm2 to a maximum of 2.7 × 1014 MIP/cm2 which allowed a systematic study of the detector performance both in the originaln-type and type-inverted regime as well as in the transition region. Charge collection efficiency, noise, leakage current and full depletion voltage were determined as a function of strip number,i.e. fluence. Full functionality of the whole detector area has been established.

An infrared laser system with variable wavelength is used to study fundamental properties of silicon microstrip detectors. Results of measurements concerning charge sharing among adjacent readout strips and depletion mapping are presented. The results are interpreted in a model framework which describes the charge sharing with the help of the so-called η-function. The wavelength dependence of the η-function is studied. Surface effects important for short wavelengths are observed.

An overview of the HERA-B silicon vertex detector system is presented. The system is optimized according to the requirements deduced from the physics goals of HERA-B. Due to the high radiation level it is necessary to exchange the modules carrying the silicon detectors once a year. The system is under construction. Data were taken with two prototype setups. Results are presented and compared with expectation.

Problems and solutions concerning the gluing of silicon detectors are discussed. The R & D work for the HERA-B vertex detector system led to gluing studies with epoxy and silicone-based adhesives used on ceramics and carbon fibre. The HERA-B solution using a silicone glue is presented.

We report on the radiation damage to silicon detectors at 25°C and 10°C induced by 190 MeV positively charged pions and 21 MeV protons. The deduced damage parameters and annealing time constants characterize the change of the diode leakage currents and full depletion voltages as a function of temperature and fluences. The results are relevant for the optimisation of the operating parameters of the HERA-B silicon vertex detector system.

The results of the first irradiation tests of newly designed silicon microstrip detectors performed with 21 MeV protons at the Max-Planck-Institut in Heidelberg are presented. The detectors were developed and produced by the semiconductor laboratory of the Max-Planck-Institut in Munich. Novel guard ring structures allow operation of the detectors at voltages exceeding 300 V.