Broad-band chopper for a CW proton linac at Fermilab

Requirements and technical limitations to the bunch-by-bunch chopper for the Fermilab Project X are discussed.Comment: 3 pp. Particle Accelerator, 24th Conference (PAC'11) 2011. 28 Mar - 1 Apr 2011. New York, US

The effect of optical substrates on micro-FTIR analysis of single mammalian cells

The study of individual cells with infrared (IR) microspectroscopy often requires living cells to be cultured directly onto a suitable substrate. The surface effect of the specific substrates on the cell growth—viability and associated biochemistry—as well as on the IR analysis—spectral interference and optical artifacts—is all too often ignored. Using the IR beamline, MIRIAM (Diamond Light Source, UK), we show the importance of the substrate used for IR absorption spectroscopy by analyzing two different cell lines cultured on a range of seven optical substrates in both transmission and reflection modes. First, cell viability measurements are made to determine the preferable substrates for normal cell growth. Successively, synchrotron radiation IR microspectroscopy is performed on the two cell lines to determine any genuine biochemically induced changes or optical effect in the spectra due to the different substrates. Multivariate analysis of spectral data is applied on each cell line to visualize the spectral changes. The results confirm the advantage of transmission measurements over reflection due to the absence of a strong optical standing wave artifact which amplifies the absorbance spectrum in the high wavenumber regions with respect to low wavenumbers in the mid-IR range. The transmission spectra reveal interference from a more subtle but significant optical artifact related to the reflection losses of the different substrate materials. This means that, for comparative studies of cell biochemistry by IR microspectroscopy, it is crucial that all samples are measured on the same substrate type. [Figure: see text

High Resolution BPM Upgrade for the ATF Damping Ring at KEK

A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility (ATF) damping ring has been accomplished, carried out by a KEK/FNAL/SLAC collaboration under the umbrella of the global ILC R&D effort. The upgrade consists of a high resolution, high reproducibility read-out system, based on analog and processing, and also implements a new automatic gain error correction schema. The technical concept and realization as well as results of beam studies are presented.Comment: 3 pp. 10th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators DIPAC 2011, 16-18 May 2011. Hamburg, German

Detecting Molecular Rotational Dynamics Complementing the Low-Frequency Terahertz Vibrations in a Zirconium-Based Metal-Organic Framework

We show clear experimental evidence of co-operative terahertz (THz) dynamics observed below 3 THz (~100 cm-1), for a low-symmetry Zr-based metal-organic framework (MOF) structure, termed MIL-140A [ZrO(O2C-C6H4-CO2)]. Utilizing a combination of high-resolution inelastic neutron scattering and synchrotron radiation far-infrared spectroscopy, we measured low-energy vibrations originating from the hindered rotations of organic linkers, whose energy barriers and detailed dynamics have been elucidated via ab initio density functional theory (DFT) calculations. For completeness, we obtained Raman spectra and characterized the alterations to the complex pore architecture caused by the THz rotations. We discovered an array of soft modes with trampoline-like motions, which could potentially be the source of anomalous mechanical phenomena, such as negative linear compressibility and negative thermal expansion. Our results also demonstrate coordinated shear dynamics (~2.5 THz), a mechanism which we have shown to destabilize MOF crystals, in the exact crystallographic direction of the minimum shear modulus (Gmin).Comment: 10 pages, 6 figure

Tracking Thermal-Induced Amorphization of a Zeolitic Imidazolate Framework via Synchrotron In Situ Far-Infrared Spectroscopy

We present the first use of in situ far-infrared spectroscopy to analyze the thermal amorphization of a zeolitic imidazolate framework material. We explain the nature of vibrational motion changes during the amorphization process and reveal new insights into the effect that temperature has on the Zn-N tetrahedra.Comment: 5 pages, 3 figures, 2 table

Reactions of Dimethylether in Single Crystals of the Silicoaluminophosphate STA-7 Studied via Operando Synchrotron Infrared Microspectroscopy

Open access via the Springer Compact Agreement. We thank the Diamond Light Source for provision of beam time and support facilities at the MIRIAM beamline B22 (Experiments SM11766-1 and SM13725-1). Financial support from the EPSRC Catalysis Hub (Suwardiyanto) and an Industrial CASE Award (EPSRC/BP Chemicals) (Price) are also acknowledged.Peer reviewedPublisher PD

Machine studies during beam commissioning of the SPS-to-LHC transfer lines

Through May to September 2008, further beam commissioning of the SPS-to-LHC transfer lines was performed. For the first time, optics and dispersion measurements were also taken in the last part of the lines, and into the LHC. Extensive trajectory and optics studies were conducted, in parallel with hardware checks. In particular dispersion measurements and their comparison with the beam line model were analysed in detail and led to propose the addition of a dispersion-free steering algorithm in the existing trajectory correction program. Its effectiveness was simulated and is briefly discussed

Effects of crystal size on methanol to hydrocarbon conversion over single crystals of ZSM-5 studied by synchrotron infrared microspectroscopy

IBM and PAW would like to thank the EPSRC and CRITICAT Centre for Doctoral Training for Financial Support [PhD studentship to IBM, and supplementary equipment grant EP/L016419/1]. The UK Catalysis Hub is thanked for resources and support provided via membership of the UK Catalysis Hub Consortium and funded by EPSRC (grants EP/I038748/1, EP/I019693/1, EP/K014706/1, EP/K014668/1, EP/K014854/1, EP/K014714/1 and EP/M013219/1). We thank the Diamond Light Source for provision of beam time and support facilities at the MIRIAM beamline B22 (Experiments SM13725-1, SM16257-1, SM18680-1, SM20906-1). IBM and PAW thank EPSRC and CRTICAT Centre for Doctoral Training for a PhD Studentship (grant EP/IO17008/1) and Supplementary Equipment Grant (EP/L016419/1). We thank Pit Losch and Hans J. Bongard, Max-Planck-Institut fur Kohlenforschung for cross-sectional SEM-EDX analysis, Daniel M. Dawson, University of St Andrews, for solid state NMR, and Juan M.Gonzalez-Carballo, University of St Andrews, for assistance with ammonia TPD. The research data supporting this publication can be accessed at https://doi.org/10.17630/306bd3c3-014b-466f-9538-b107628c847d.Peer reviewedPostprin