Investigation of hard x-ray emissions from terawatt laser-irradiated foils at the Matter in Extreme Conditions instrument of the Linac Coherent Light Source. (1st April 2022)

• Record Type: Journal Article
• Authors: Fletcher, L.B.; Curry, C.B.; Gauthier, M.; Glenn, G.D.; Chen, Z.; Cunningham, E.; Descamps, A.; Frost, M.; Galtier, E.C.; Heimann, P.; Kim, J.B.; Mo, M.; Ofori-Okai, B.K.; Peebles, J.; Seiboth, F.; Treffert, F.; Dyer, G.M.; McBride, E.E.; Glenzer, S.H.
• Is Part Of: Journal of instrumentation. Volume 17:Number 4(2022)
• Publication Date: 2022-04-01
• Subjects: Plasma diagnostics - interferometry, spectroscopy and imaging -- Radiation-hard detectors -- Scintillators, scintillation and light emission processes (solid, gas and liquid scintillators) -- X-ray detectors; Scientific apparatus and instruments -- Periodicals; 502.84
• DOI: 10.1088/1748-0221/17/04/T04004
• Languages: English
• ISSNs: 1748-0221

Abstract

Abstract: In this technical report, we investigate the hard x-ray background produced at the Matter in Extreme Conditions (MEC) instrument of the Linac Coherent Light Source (LCLS) from the interaction of a high-intensity (∼10 19 W/cm 2 ) femtosecond laser with solid μm-thick aluminum and polypropylene targets. This background is dominated by bremsstrahlung from laser-generated relativistic electrons, and a measurement of the broadband x-ray spectrum via differential x-ray energy filtering was used to infer the existence of two electron distributions with electron temperatures of Thot = 500 ± 300 keV and Tcold = 5.0 ± 0.5 keV. Simultaneous single-shot measurements of the proton energies accelerated from laser-irradiated solid targets could be correlated with these measurements to further constrain the on-target laser parameters. Measurements of the hard x-ray photon background generated from laser-irradiated foils can be used to directly monitor and test the signal-to-background limits of silicon-based hybrid pixel array x-ray detectors at laser intensities approaching 10 19 W/cm 2 .