Radiation Safety at FLUTE with Special Emphasis on Activation Issues

The accelerator FLUTE (name abbreviation derived from its German name: Ferninfrarot Linac- und TestExperiment) has been set up in cooperation with DESY and PSI [1]. The electron source and diagnostics has commenced operation. General safety issues of FLUTE are covered in this paper. The activation of the accelerator and vacuum parts were predicted previously [2]. The attention is given to the activation of aluminum and impurities in the electron absorber of the beam dump. Potential air activation in the experimental hall is also discussed

Structural Amyloid Plaque Polymorphism is Associated with Distinct Lipid Accumulations Revealed by Trapped Ion Mobility Mass Spectrometry Imaging (TIMS MSI)

Understanding of Alzheimer’s disease (AD) pathophysiology, requires molecular assessment of how key pathological factors, specifically amyloid β (Aβ) plaques, influence the surrounding microenvironment. Here, neuronal lipids have been implicated in Aβ) plaque pathology, though the lipid microenvironment in direct proximity to Aβ plaques are still not fully resolved. A further challenge is the microenvironmental molecular heterogeneity, across structurally polymorphic Aβ features - such as diffuse, immature and mature, fibrillary aggregates, whose resolution requires the integration of advanced, multimodal chemical imaging tools. Herein, we used matrix assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) trapped ion mobility spectrometry Time-of-Flight (TIMS TOF) in combination with hyperspectral confocal microscopy to probe the lipidomic microenvironment associated with structural polymorphism of Aβ plaques in transgenic Alzheimer’s disease mice (tgAPPSWE). Using on tissue and ex situ validation, TIMS MS/MS facilitated unambiguous identification of isobaric lipid species that showed plaque pathology associated localizations. Integrated multivariate imaging data analysis revealed multiple, Aβ plaque enriched lipid patterns for gangliosides (GM), phosphoinositols (PI), phosphoethanolamines (PE) and phosphatidic acids (PA). Conversely, sulfatides (ST), cardiolipins (CL) and polyunsaturated fatty acid conjugated -phosphoserines (PS) and - PE were depleted at plaques. Hyperspectral amyloid imaging further delineated unique distribution of PA, PE to mature plaque core regions, while PI, LPI, GM2 and GM3 localized to immature Aβ aggregates present within the periphery of individual Aβ plaques. Finally, we followed AD pathology associated lipid changes over time, identifying plaque growth and maturation to be characterized by peripheral accumulation of PI (18:0/22:6). Together, these data demonstrate the potential of multimodal imaging approaches to overcome limitations associated with conventional advanced MS imaging applications. This allowed for differentiation of both distinct lipid components in a complex micro environment, as well as their correlation to disease relevant amyloid plaque polymorphs

Observation of microwave radiation using low-cost detectors at the anka storage ring

Synchrotron light sources emit Coherent Synchrotron Radiation (CSR) for wavelengths longer than or equal to the bunch length. At most storage rings CSR cannot be observed, because the vacuum chamber cuts off radiation with long wavelengths. There are different approaches for shifting the CSR to shorter wavelengths that can propagate through the beam pipe, e.g.: the accelerator optics can be optimized for a low momentum compaction factor, thus reducing the bunch length. Alternatively, laser slicing can modulate substructures on long bunches [1]. Both techniques extend the CSR spectrum to shorter wavelengths, so that CSR is emitted at wavelengths below the waveguide shielding cut off. Usually fast detectors, like superconducting bolometer detector systems or Schottky barrier diodes, are used for observation of dynamic processes in accelerator physics. In this paper, we present observations of microwave radiation at ANKA using an alternative detector, a LNB (Low Noise Block) system. These devices are usually used in standard TV-SAT-receivers and are very cheap. We determined the time response of LNBs to be below 100 ns. The sensitivity of LNBs is optimized to detect very low intensity ”noise-like” signals. This microwave radiation study shows the possibility to apply the LNB for bunch length monitoring