Setting reference targets

Reference Targets are used to represent virtual quantities like the magnetic axis of a magnet or the definition of a coordinate system. To explain the function of reference targets in the sequence of the alignment process, this paper will first briefly discuss the geometry of the trajectory design space and of the surveying space, then continue with an overview of a typical alignment process. This is followed by a discussion on magnet fiducialization. While the magnetic measurement methods to determine the magnetic centerline are only listed (they will be discussed in detail in a subsequent talk), emphasis is given to the optical/mechanical methods and to the task of transferring the centerline position to reference targets

Methane Pyrolysis for Zero-Emission Hydrogen Production: A Potential Bridge Technology from Fossil Fuels to a Renewable and Sustainable Hydrogen Economy

Hydrogen plays a key role in many industrial applications and is currently seen as one of the most promising energy vectors. Many efforts are being made to produce hydrogen with zero CO2 footprint via water electrolysis powered by renewable energies. Nevertheless, the use of fossil fuels is essential in the short term. The conventional coal gasification and steam methane reforming processes for hydrogen production are undesirable due to the huge CO2 emissions. A cleaner technology based on natural gas that has received special attention in recent years is methane pyrolysis. The thermal decomposition of methane gives rise to hydrogen and solid carbon, and thus, the release of greenhouse gases is prevented. Therefore, methane pyrolysis is a CO2-free technology that can serve as a bridge from fossil fuels to renewable energies

The potential of NO⁺ and O₂^+• in switchable reagent ion Proton Transfer Reaction time-of-flight Mass Spectrometry

Selected ion flow tube mass spectrometry (SIFT-MS) and Proton Transfer Reaction mass spectrometry with switchable reagent ion capability (PTR+SRI-MS) are analytical techniques for real-time qualification and quantification of compounds in gas samples with trace level concentrations. In the detection process, neutral compounds—mainly volatile organic compounds—are ionized via chemical ionization with ionic reagent or primary ions. The most common reagent ions are H3O+, NO+ and O2 +•. While ionization with H3O+ occurs by means of proton transfer, the ionization via NO+ and O2 +• offers a larger variety on ionization pathways, as charge transfer, hydride abstraction etc. are possible. The distribution of the reactant into various reaction channels depends not only on the usage of either NO+ or O2 +•, but also on the class of analyte compounds. Furthermore, the choice of the reaction conditions as well as the choice of either SIFT-MS or PTR+SRI-MS might have a large impact on the resulting products. Therefore, an overview of both NO+ and O2 +• as reagent ions is given, showing differences between SIFT-MS and PTR+SRI-MS as used analytical methods revealing the potential how the knowledge obtained with H3O+ for different classes of compounds can be extended with the usage of NO+ and O2 +•

A Gas Generating System for Complex Gas Mixtures – Multifunctional Application in PTR Method Optimization and Downstream Methanol Synthesis

The multifunctional applicability of a gas mixing system is presented within the scope of Carbon2Chem® for the simulation of steel mill flue gases and their application in downstream processes. A special focus is set on the parallel operation of the gas mixing system to enable PTR-MS method optimization and methanol synthesis with simulated real gas matrices. Information is gathered for the design of downstream processes and their application, where methanol synthesis is chosen as a model reaction. A proof-of-principle study is presented where operation of a catalytic reactor setup in combination with the gas mixing system and a compressor generate reproducible results. The addition of potential trace components in methanol synthesis is exemplarily demonstrated using ammonia. With respect to the PTR-MS application, the dosing of two calibration gas standards, toluene and carbonyl sulfide, via the gas mixing system were analyzed in detail. The obtained results give insight into its applicability to simulate traces and enables the further development of analytical methods for the analysis of trace impurities in the ppb and ppt range in complex gas mixtures

Oxygen Poisoning in Laboratory Testing of Iron‐Based Ammonia Synthesis Catalysts and its Potential Sources

The influence of oxygen poisoning on a state-of-the-art multipromoted iron-based industrial catalyst for ammonia synthesis as well as the effectivity of different gas purification methods to prevent oxygen poisoning for experiments on laboratory scale were studied in detail. Additionally, the observed results were compared to a common oxygen poisoning test from literature, which on the one hand confirmed its usability in a wide range of conditions, but on the other hand also demonstrated the limitations of this test

Determination of trace compounds and artifacts in nitrogen background measurements by proton transfer reaction time-of-flight mass spectrometry under dry and humid conditions

A qualitative analysis was applied for the determination of trace compounds at the parts per trillion in volume (pptv) level in the mass spectra of nitrogen of different qualities (5.0 and 6.0) under dry and humid conditions. This qualitative analysis enabled the classification and discovery of hundreds of new ions (e.g., [Sx]H+ species) and artifacts such as parasitic ions and memory effects and their differentiation from real gas impurities. With this analysis, the humidity dependency of all kind of ions in the mass spectrum was determined. Apart from the inorganic artifacts previously discovered, many new organic ions were assigned as instrumental artifacts and new isobaric interferences could be elucidated. From 1140 peaks found in the mass range m/z 0–800, only 660 could be analyzed due to sufficient intensity, from which 463 corresponded to compounds. The number of peaks in nitrogen proton transfer reaction (PTR) spectra was similarly dominated by nonmetallic oxygenated organic compounds (23.5%) and hydrocarbons (24.1%) Regarding only gas impurities, hydrocarbons were the main compound class (50.2%). The highest contribution to the total ion signal for unfiltered nitrogen under dry and humid conditions was from nonmetallic oxygenated compounds. Under dry conditions, nitrogen-containing compounds exhibit the second highest contribution of 89% and 96% for nitrogen 5.0 and 6.0, respectively, whereas under humid conditions, hydrocarbons become the second dominant group with 69% and 86% for nitrogen 5.0 and 6.0, respectively. With the gathered information, a database can be built as a tool for the elucidation of instrumental and intrinsic gas matrix artifacts in PTR mass spectra and, especially in cases, where dilution with inert gases plays a significant role

The Carbon2Chem_® Laboratory in Oberhausen - A Workplace for Lab-Scale Setups within the Cross-Industrial Project

Within the Carbon2Chem® network, basic research is mandatory for a successful implementation and realization of sustainable technologies for CO2 emission reduction. For this purpose, the exchange of knowledge between the project partners in the individual subareas is as essential as obtaining precise data on the fundamental parameters on a laboratory scale in order to transfer them later to large-scale plants. Therefore, the Carbon2Chem® laboratory offers a platform to gain detailed insights into the individual sub-processes and to then apply these findings at the technical center in Duisburg

Abundances of Baade's Window Giants from Keck/HIRES Spectra: II. The Alpha- and Light Odd Elements

We report detailed chemical abundance analysis of 27 RGB stars towards the Galactic bulge in Baade's Window for elements produced by massive stars: O, Na, Mg, Al, Si, Ca and Ti. All of these elements are overabundant in the bulge relative to the disk, especially Mg, indicating that the bulge is enhanced in Type~II supernova ejecta and most likely formed more rapidly than the disk. We attribute a rapid decline of [O/Fe] to metallicity-dependent yields of oxygen in massive stars, perhaps connected to the Wolf-Reyet phenomenon. he explosive nucleosynthesis alphas, Si, Ca and Ti, possess identical trends with [Fe/H], consistent with their putative common origin. We note that different behaviors of hydrostatic and explosive alpha elements can be seen in the stellar abundances of stars in Local Group dwarf galaxies. We also attribute the decline of Si,Ca and Ti relative to Mg, to metallicity- dependent yields for the explosive alpha elements from Type~II supernovae. The starkly smaller scatter of [/Fe] with [Fe/H] in the bulge, as compared to the halo, is consistent with expected efficient mixing for the bulge. The metal-poor bulge [/Fe] ratios are higher than ~80% of the halo. If the bulge formed from halo gas, the event occured before ~80% of the present-day halo was formed. The lack of overlap between the thick and thin disk composition with the bulge does not support the idea that the bulge was built by a thickening of the disk driven by the bar. The trend of [Al/Fe] is very sensitive to the chemical evolution environment. A comparison of the bulge, disk and Sgr dSph galaxy shows a range of ~0.7 dex in [Al/Fe] at a given [Fe/H], presumably due to a range of Type~II/Type~Ia supernova ratios in these systems.Comment: 51 pages, 6 tables, 27 figures, submitte

Laser Tracker Test Facility at SLAC - Progress Report

Physics experiments at SLAC require high accuracy positioning, e. g. 100 {micro}m over a distance of 150 m or 25 {micro}m in a 10 x 10 x 3 meter volume. Laser Tracker measurement systems have become one of the most important tools for achieving these accuracies when mapping components. In order to improve and get a better understanding of laser tracker measurement tolerances we extended our laboratory with a rotary calibration table (Kugler GmbH) providing an accuracy of better than 0.2 arcsec. This paper gives an overview of the calibration table and its evaluation. Results of tests on two of our Laser Trackers utilizing the new rotary table as well as the SLAC interferometer bench are presented