Design of analog front-ends for the RD53 demonstrator chip

The RD53 collaboration is developing a large scale pixel front-end chip, which will be a tool to evaluate the performance of 65 nm CMOS technology in view of its application to the readout of the innermost detector layers of ATLAS and CMS at the HL-LHC. Experimental results of the characterization of small prototypes will be discussed in the frame of the design work that is currently leading to the development of the large scale demonstrator chip RD53A to be submitted in early 2017. The paper is focused on the analog processors developed in the framework of the RD53 collaboration, including three time over threshold front-ends, designed by INFN Torino and Pavia, University of Bergamo and LBNL and a zero dead time front-end based on flash ADC designed by a joint collaboration between the Fermilab and INFN. The paper will also discuss the radiation tolerance features of the front-end channels, which were exposed to up to 800 Mrad of total ionizing dose to reproduce the system operation in the actual experiment

Feasibility studies for the measurement of time-like proton electromagnetic form factors from p¯ p→ μ+μ- at P ¯ ANDA at FAIR

This paper reports on Monte Carlo simulation results for future measurements of the moduli of time-like proton electromagnetic form factors, | GE| and | GM| , using the p¯ p→ μ+μ- reaction at P ¯ ANDA (FAIR). The electromagnetic form factors are fundamental quantities parameterizing the electric and magnetic structure of hadrons. This work estimates the statistical and total accuracy with which the form factors can be measured at P ¯ ANDA , using an analysis of simulated data within the PandaRoot software framework. The most crucial background channel is p¯ p→ π+π-, due to the very similar behavior of muons and pions in the detector. The suppression factors are evaluated for this and all other relevant background channels at different values of antiproton beam momentum. The signal/background separation is based on a multivariate analysis, using the Boosted Decision Trees method. An expected background subtraction is included in this study, based on realistic angular distributions of the background contribution. Systematic uncertainties are considered and the relative total uncertainties of the form factor measurements are presented

PANDA Phase One - PANDA collaboration

The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or P¯ANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton–nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper

Measuring and modelling seasonal variation of gross nitrification rates in response to long-term fertilisation

The formation of nitrate (nitrification) in soils is an important process that influences N availability for plant uptake and potential N losses as well. Gross nitrification is an effective measure by which to test mechanistic ecosystem models for predictability because gross rates can widely differ between sites, even if net production is similar between these sites. <br><br> A field experiment was designed to (i) determine gross nitrification rates in response to fertilisation and (ii) to verify the idea that seasonal variations of gross rates in soils can be readily predicted by soil moisture and soil temperature. <br><br> Gross nitrification rates were measured by a Barometric Process Separation (BaPS). The BaPS measurements were validated with the commonly used <sup>15</sup>N pool dilution technique measurements at six times. In general, the rates determined from both measurement approaches were in the same order of magnitude and showed a good correlation. <br><br> The effects of 100 years of fertilisation (mineral fertiliser, manure and control) on gross nitrification rates were investigated. During 2004 soil samples from the long-term "static fertilisation experiment" at Bad Lauchstädt were sampled weekly and were measured in the laboratory under field conditions and subsequently under standardised conditions (16°C soil temperature and −30 kPa matrix potential) with the BaPS system. Gross nitrification rates determined under standardised conditions did not show any seasonal trend but did, however, reveal a high temporal variability. Gross nitrification rates determined by the BaPS-method under field conditions showed also a high temporal variability and ranged from 5 to 77 μg N h<sup>−1</sup> kg<sup>−1</sup> dry mass, 2 to 74 μg N h<sup>−1</sup> kg<sup>−1</sup> dry mass and 0 to 49 μg N h<sup>−1</sup> kg<sup>−1</sup> dry mass with respect to manure, mineral fertiliser, and control. The annual average was 0.34, 0.27 and 0.19 g N a<sup>−1</sup> kg<sup>−1</sup> dry mass for the manure site, mineral fertiliser site and control site, respectively. On all sites gross nitrification revealed a strong seasonal dynamic. Three different models were applied for reproducing the measured results. Test models could explain 75% to 78% of variability at the manure site, 66% to 77% of variability at the mineral fertiliser site, and 39% to 63% of variability at the control site. The model parameterisation shows that the temperature sensitivity of gross nitrification differs between the three neighbouring sites. Hence, a temperature response function in an ecosystem model has to consider the site specificity in order to adequately predict the effects of future climate change on the soil N cycle

Spatially resolved transport properties in radially compressed bead packings studies by PFG NMR.

Pulsed field gradient (PFG) multi-echo (ME) and turbo spin-echo (TSE) imaging is used to study dispersive flow in radially compressed chromatographic columns packed with porous silica beads. By using the pulsed field gradient turbo spin-echo sequence spatially resolved displacement imaging can be accelerated by a factor of 16. The positive effect of homogeneous radial packing on flow velocity and dispersion is demonstrated. Small heterogeneities of only a few percent are shown to cause changes of the dispersion coefficient of up to 50%

Modelle zur Beschreibung des Leichtwasserreaktorverhaltens bei schweren Stoerfaellen fuer die Programme SCDAP/RELAP5, ATHLET/SA, CATHARE/ICARE, MELCORE u.a 1. Technischer Fachbericht zum Forschungsvorhaben BMFT 1500 831 7: Vergleichende Bewertung von Programmsystemen zur Simulation schwerer Stoerfaelle, Beitraege zur ATHLET/CD Codeentwicklung

Within the scope of the project BMFT No. 15008317 entitled ''Comparative Assessment of Different Computer Codws for Severe Accident Analysis, Contribution to the ATHLET/SA-Code Development'' the codes ATHLET/SA, CATHARE/ICARE, MELCOR and SCDAP/RELAP5 are investigated. Emphasis is put on a comparison and an assessment of the governing modelling features implemented and operating in the codes under consideration. The codes are evaluated and compared on the base of selected experiments (especially the CORA experimental program of the Karlsruhe Research Center) and relevant severe accident scenarios. The present report is a reference study dealing with the governing models implemented in the severe accident codes SCDAP/RELAP5, ATHLET/SA, CATHARE/ICARE, MELCOR, KESS-III, MAAP and MELPROG/TRAC. Emphaisis is laid on the following models (molstly implemented in form of modules in the respective codes) dealing with: - thermal hydraulics; - heat generation and heat structures; - Radiation heat transfer; - mechanical (rod) behaviour; - core heatup, meltdown and relocation; - chemical reaction; - fission product release and transport; -material properties; - specific components. (orig.)Im Rahmen des Vorhabens BMFT-15008317 mit dem Titel ''Vergleichende Bewertung von Programmsystemen zur Simulation schwerer Stoerfaelle, Beitraege zur ATHLET/SA-Codeentwicklung'', werden die wichtigsten Programmsysteme, d.h. vor allem ATHLET/SA, CATHARE/ICARE, MELCOR und SCDAP/REALAP5 einer Analyse insbesondere bezueglich des Umfangs und der Leistungsfaehigkeit massgebender Modelle unterzogen. Die Modelle in den Programmen werden verglichen, die Programme verfuegbar gemacht und anhand ausgewaehlter Versuche (insbesondere des CORA-Versuchsprogramms des Kernforschungszentrums Karlsruhe) sowie festzulegender Stoerfallszenarien untereinander und anhand experimenteller Daten getestet. Der vorliegende Bericht ist eine Literaturstudie derjenigen Modelle in den Programmsystemen SCDAP/RELAP5, ATHLET/SA, CATHARE/ICARE, MELCOR, KESS-III, MAAP und MELPROG/TRAC, welche die Vorgaenge im Kuehlkreislauf und insbesondere im Kern waehrend eines schweren Stoerfalls beschreiben. Dazu gehoeren (meist in Form von Modulen in die Programmsysteme eingebunden) Modelle fuer die -Thermofluiddynamik; - Waermeerzeugung und -strukturen; - Mechanik (mechanisches Stabverhalten); - Kernaufheizung, Schmelzebildung und -verlagerung; - chemischen Reaktionen (Oxidation); - Spaltproduktfreisetzung; - Stoffwerte und speziellen Konfigurationen. (orig.)SIGLEAvailable from TIB Hannover: RO 9602(19) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman