A compact proton spectrometer for measurement of the absolute DD proton spectrum from which yield and ρR are determined in thin-shell inertial-confinement-fusion implosions

M J Rosenberg; A B Zylstra; J A Frenje; H G Rinderknecht; M Gatu Johnson; C J Waugh; F H Séguin; H Sio; N Sinenian; C K Li; R D Petrasso; V Yu Glebov; M Hohenberger; C Stoeckl; T C Sangster; C B Yeamans; S LePape; A J Mackinnon; R M Bionta; B Talison; D T Casey; O L Landen; M J Moran; R A Zacharias; J D Kilkenny; A Nikroo

doi:10.1063/1.4897193

A compact proton spectrometer for measurement of the absolute DD proton spectrum from which yield and ρR are determined in thin-shell inertial-confinement-fusion implosions

Rev Sci Instrum. 2014 Oct;85(10):103504. doi: 10.1063/1.4897193.

Authors

M J Rosenberg¹, A B Zylstra¹, J A Frenje¹, H G Rinderknecht¹, M Gatu Johnson¹, C J Waugh¹, F H Séguin¹, H Sio¹, N Sinenian¹, C K Li¹, R D Petrasso¹, V Yu Glebov², M Hohenberger², C Stoeckl², T C Sangster², C B Yeamans³, S LePape³, A J Mackinnon³, R M Bionta³, B Talison³, D T Casey³, O L Landen³, M J Moran³, R A Zacharias³, J D Kilkenny⁴, A Nikroo⁴

Affiliations

¹ Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
² Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.
³ Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
⁴ General Atomics, San Diego, California 92186, USA.

PMID: 25362390
DOI: 10.1063/1.4897193

Abstract

A compact, step range filter proton spectrometer has been developed for the measurement of the absolute DD proton spectrum, from which yield and areal density (ρR) are inferred for deuterium-filled thin-shell inertial confinement fusion implosions. This spectrometer, which is based on tantalum step-range filters, is sensitive to protons in the energy range 1-9 MeV and can be used to measure proton spectra at mean energies of ∼1-3 MeV. It has been developed and implemented using a linear accelerator and applied to experiments at the OMEGA laser facility and the National Ignition Facility (NIF). Modeling of the proton slowing in the filters is necessary to construct the spectrum, and the yield and energy uncertainties are ±<10% in yield and ±120 keV, respectively. This spectrometer can be used for in situ calibration of DD-neutron yield diagnostics at the NIF.