Determining spectral response of the National Ignition Facility particle time of flight diagnostic to x rays

B Reichelt; N Kabadi; J Pearcy; M Gatu Johnson; S Dannhoff; B Lahmann; J Frenje; C K Li; G Sutcliffe; J Kunimune; R Petrasso; H Sio; A Moore; E Mariscal; E Hartouni

doi:10.1063/5.0101725

Determining spectral response of the National Ignition Facility particle time of flight diagnostic to x rays

Rev Sci Instrum. 2023 Mar 1;94(3):033510. doi: 10.1063/5.0101725.

Authors

B Reichelt¹, N Kabadi¹, J Pearcy¹, M Gatu Johnson¹, S Dannhoff¹, B Lahmann¹, J Frenje¹, C K Li¹, G Sutcliffe¹, J Kunimune¹, R Petrasso¹, H Sio², A Moore², E Mariscal², E Hartouni²

Affiliations

¹ Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
² Lawrence Livermore National Laboratory, Livermore, California 94550, USA.

PMID: 37012781
DOI: 10.1063/5.0101725

Abstract

The Particle Time of Flight (PTOF) diagnostic is a chemical vapor deposition diamond detector used for measuring multiple nuclear bang times at the National Ignition Facility. Due to the non-trivial, polycrystalline structure of these detectors, individual characterization and measurement are required to interrogate the sensitivity and behavior of charge carriers. In this paper, a process is developed for determining the x-ray sensitivity of PTOF detectors and relating it to the intrinsic properties of the detector. We demonstrate that the diamond sample measured has a significant non-homogeneity in its properties, with the charge collection well described by a linear model ax + b, where a = 0.63 ± 0.16 V^-1 mm^-1 and b = 0.00 ± 0.04 V^-1. We also use this method to confirm an electron to hole mobility ratio of 1.5 ± 1.0 and an effective bandgap of 1.8 eV rather than the theoretical 5.5 eV, leading to a large sensitivity increase.