high-energy-density physics

Charged-particle spectrometry at the NIF and OMEGA

Our Charged-Particle Spectrometry program is designed to provide diagnostic information about ICF plasmas by measuring energy spectra of charged fusion products and ablator ions. These measurements provide fusion yields, ion temperatures, areal density and areal density symmetry of fuel and shell, stopping power in hot plasmas, and quantification of anomalous acceleration effects. Two magnet-based spectrometers [see here] at OMEGA, and many compact “wedge-range-filter” proton spectrometers [see here, here, and here] are used at OMEGA and at the NIF. Measured spectra include lines of D³He protons (14.7 MeV) and alphas (3.6 MeV), DT alphas (3.5 MeV), and DD protons (3.0 MeV), tritons (1.0 MeV), and ³He (0.8 MeV), T-³He deuterons (9.5 MeV), and continuous “knock-on” spectra of deuterons, tritons, and protons ejected in elastic collisions with 14-MeV fusion neutrons.

High resolution neutron spectrometry for diagnosing ICF implosions and basic science experiments at OMEGA and the NIF

This document describes two neutron spectrometers, called Magnetic Recoil Spectrometer (MRS), that have been built and implemented at the OMEGA laser facility and at the National Ignition Facility. They supply absolute measurements of the neutron spectrum in the range 6 to 30 MeV, from which fuel areal density, ion temperature, and neutron yield can be determined for ICF implosions. The spectrometers have also provided the first measurements of the astrophysical S-factor (or cross-section) for the TT reaction at energies inaccessible by conventional accelerator-based techniques.

The MIT Accelerator Facility for diagnostic development

This document describes the student-built MIT Accelerator Facility for Diagnostic Development. The Facility includes a linear ion accelerator that generates DD, D³He and DT fusion products, an x-ray source, a pulsed DT neutron source, and an etch/scan lab allows for CR-39 processing. All MIT diagnostics are developed, tested and calibrated at this Facility by our students.

Proton Radiography

Proton emission imaging of ICF burn regions

Multi-PTD: Multiple particle burn history diagnostic

MagPTOF: bang time detector