Development of a Thomson Parabola Charged-particle Spectrometer for NIF and NIF-ARC Experiments

Raspberry Simpson, Massachusetts Institute of Technology

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At Lawrence Livermore National Laboratory's National Ignition Facility (NIF), numerous diagnostics based on charged-particle detection have produced invaluable data for the high energy density physics and inertial confinement fusion communities, such as wedge range filter proton spectrometers (WRFs), the magnetic recoil spectrometer (MRS), particle time-of-flight detectors (pTOF/mag-pTOF) and step-range filter spectrometers (SRFs). However, the existing diagnostics are limited both in energy range and species of particle that may be detected. A capability to measure various particles simultaneously with a broad energy range (~0.5-100 MeV) would be crucial to a wide variety of applications at NIF, including ion acceleration experiments with the Advanced Radiographic Capability (ARC) short-pulse laser, stopping-power measurements and experiments involving collisionless shocks. Building on the design of the OMEGA Thomson Parabola Ion Energy Analyzer (TPIE), we present a preliminary design for a new charged particle spectrometer at NIF called the Thomson Parabola Charged Particle Spectrometer (TP-CPS). As the name suggests, this spectrometer will be based on the well-known Thomson parabola concept in which particles' species and energy are discriminated using a combined electric and magnetic field.

Abstract Author(s): Raspberry Simpson, Johan Frenje, Maria Gatu-Johnson, Frederick Seguin, Chi-Kang Li, Richard Petrasso, Tammy Ma, Alex Zylstra, Derek Mariscal, Charles Sorce, Dino Mastrimone