Author: Norem, J.
Paper Title Page
MOPPR067 Simulations of Fast X-ray Detectors Based on Multichannel Plates 939
  • Z. Insepov, B.W. Adams, J. Norem
    ANL, Argonne, USA
  • V. Ivanov
    Muons, Inc, Batavia, USA
  Funding: Argonne National Laboratory
High-performance detectors with high spatial and time resolutions are required for imaging of fast processes, time-resolved coherent scattering, and time-resolved x-ray spectroscopy. Recent developments in micro-channel plate (MCP) technology are important for sub-ns and 2d-spatially resolving x-ray detection. A Monte Carlo code was used to calculate the yields of secondary electrons emitted from a photo-cathode irradiated by X-rays, E=1-10 keV. Several photo-cathode materials were tested, including Al2O3, MgO, carbon, copper, WO3. The calculated emissive characteristics were used as input parameters of a second Monte Carlo code that was capable of calculating the gain/time characteristics of the MCP based X-Ray detector. A new type of X-Ray detector based on MCPs coated by resistive and emissive layers inside the pores by using atomic-layer deposition (ALD) promises a large parameter space where optimizations can take place. These optimizations for x-ray-specific applications are expected to improve the spatial resolution to 100 microns and the time resolution to 50 ps, and the development of high-quantum-yield photo-cathodes based on MCPs with grazing incidence inside the pores.
THEPPB013 Progress in Modeling Arcs 3260
  • J. Norem, Z. Insepov
    ANL, Argonne, USA
  • S. Mahalingam, S.A. Veitzer
    Tech-X, Boulder, Colorado, USA
  • A. Moretti
    Fermilab, Batavia, USA
  • I. Morozov, G.E. Norman
    JIHT RAS, Moscow, Russia
  Funding: DOE Office of High Energy Physics.
We are continuing to extend and simplify our understanding of vacuum arcs. We believe that all the breakdown phenomena we see (with and without B fields) can be explained by: 1) fracture due to electrostatic forces at surface crack junctions, 2) the development of a unipolar arc driven by the cavity electric field, and 3) cooling, and cracking of the surface after the event is finished. Recent progress includes the evaluation of non-Debye sheaths using Molecular Dynamics, studies of sheath driven instabilities, a model of degradation of gradient limits in strong B fields, analysis of the variety of arcs that can occur in cavities and their damage and further studies of breakdown triggers.