Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Optical Picosecond MCPI-Based Imagers SPIE Optics+Photonics Symposium August 14, 2012 Target Diagnostics Physics and Engineering for Inertial Confinement Fusion Robert A. Buckles, Robert L. Guyton, Patrick W. Ross National Security Technologies - Livermore This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/

Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Overview Desired performance specifications Time dilation techniques Direct imaging Prototype Design Wideband techniques

Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Performance Specifications Multiple frames, 10 mm, 5 ps FWHM, ps interframe time ps Time 200 ps Frame # 1234 FWHM 5 ps Time 40 ps Frame # 1234

Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Time Dilation Concepts Long drift space allows greater time resolution (20x dilation) and eases electronic demands. Space charge spreading requires magnetic confinement for fine spatial resolution (20 μm). –Onset of strong space charge effects: 10 mA/mm 2 (30 electrons in 10x10 μm pixel, 5 ps) –T. J. Hilsabeck (General Atomics) “Pulse-dilation enhanced gated optical imager with 5 ps resolution,” REVIEW OF SCIENTIFIC INSTRUMENTS 81, 10E Short drift space requires wideband electronics (110 GHz) and robust signal delivery.

Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Direct Imaging Compact, all-electronic, no magnetic fields. Gated imagers presently achieve ~100 ps frame time limited by electronics and signal delivery. Stripline imagers achieve slightly better. –30 ps optical –laser-triggered photoconductive switch Need similar design, careful impedance matching, and permanent hermetic seal. NSTec fast-gate 18 mm MCPI LANL/LLNL 4-strip GXD head

Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Design Concept Direct drive with ultrafast pulser MCP structure with butt-coupled transformer, V- or W-band vacuum sealed feedthrough. Guanella-style Series-TLT or Hecken-Klopfenstein Taper. Cascadeable MCPs with (small) drift space for 1 ps resolution. Quick prototype with Conflat seal. Single-MCPI prototype with ultra-wideband drive.

Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Picosecond Avalanche Pulsers Modified Booth chargeline pulser –SDRD 2004 Report DOE/NV/ Controlled impedance Controlled dispersion 3kV, ps falling edge Limited by PCB and package parasitics Novel designs eliminate all inductance. PCB version of NSTec avalanche pulser.. 3 kV, ps edges (back edge is mismatched)

Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Wideband Transformer STLT –Precision matched along whole path. Embedded microstrip/parallel-plate –No vias –No reflections –Ultra-low dispersion and loss Teflon-Kapton Topas Copolymer –Shorter than Hecken-Klopfenstein Taper

Vision – Service – Partnership Managed and Operated by National Security Technologies, LLC Nevada National Security Site Optical Picosecond MCPI-based Imagers: August 14, 2012 Conceptual Final Form High QE – Ultrafast photocathode Dual MCP “grids” with slight drift space Four individual 10 mm images < 5 ps optical gates