High-resolution measurements of the DT neutron spectrum using new CD foils in the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

M Gatu Johnson; J A Frenje; R M Bionta; D T Casey; M J Eckart; M P Farrell; G P Grim; E P Hartouni; R Hatarik; M Hoppe; J D Kilkenny; C K Li; R D Petrasso; H G Reynolds; D B Sayre; M E Schoff; F H Séguin; K Skulina; C B Yeamans

doi:10.1063/1.4959946

High-resolution measurements of the DT neutron spectrum using new CD foils in the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

Rev Sci Instrum. 2016 Nov;87(11):11D816. doi: 10.1063/1.4959946.

Authors

M Gatu Johnson¹, J A Frenje¹, R M Bionta², D T Casey², M J Eckart², M P Farrell³, G P Grim², E P Hartouni², R Hatarik², M Hoppe³, J D Kilkenny³, C K Li¹, R D Petrasso¹, H G Reynolds³, D B Sayre², M E Schoff³, F H Séguin¹, K Skulina², C B Yeamans²

Affiliations

¹ Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
² Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
³ General Atomics, San Diego, California 92186, USA.

PMID: 27910455
DOI: 10.1063/1.4959946

Abstract

The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility measures the DT neutron spectrum from cryogenically layered inertial confinement fusion implosions. Yield, areal density, apparent ion temperature, and directional fluid flow are inferred from the MRS data. This paper describes recent advances in MRS measurements of the primary peak using new, thinner, reduced-area deuterated plastic (CD) conversion foils. The new foils allow operation of MRS at yields 2 orders of magnitude higher than previously possible, at a resolution down to ∼200 keV FWHM.