Enhanced brightness of a laser-driven X-ray and particle source by microstructured surfaces of silicon targets

TY - JOUR

T1 - Enhanced brightness of a laser-driven X-ray and particle source by microstructured surfaces of silicon targets

AU - Ebert, Tina

AU - Neumann, Nico W.

AU - Döhl, Leonard N.K.

AU - Jarrett, Jonathan

AU - Baird, Christopher

AU - Heathcote, Robert

AU - Hesse, Markus

AU - Hughes, Aasia

AU - McKenna, Paul

AU - Neely, David

AU - Rusby, Dean

AU - Schaumann, Gabriel

AU - Spindloe, Christopher

AU - Tebartz, Alexandra

AU - Woolsey, Nigel

AU - Roth, Markus

PY - 2020/4/20

Y1 - 2020/4/20

N2 - The production of intense X-ray and particle sources is one of the most remarkable aspects of high energy laser interaction with a solid target. Wide application of these laser-driven secondary sources requires a high yield, which is partially limited by the amount of laser energy absorbed by the target. Here, we report on the enhancement of laser absorption and X-ray and particle flux by target surface modifications. In comparison to targets with flat front surfaces, our experiments show exceptional laser-to-target performance for our novel cone-shaped silicon microstructures. The structures are manufactured via laser-induced surface structuring. Spectral and spatial studies of reflectance and X-ray generation reveal significant increases of the silicon Kα line and a boost of the overall X-ray intensity, while the amount of reflected light decreases. Also, the proton and electron yields are enhanced, but both temperatures remain comparable to those of flat foil targets. We support the experimental findings with 2D particle in cell simulations to identify the mechanisms responsible for the strong enhancement. Our results demonstrate how custom surface structures can be used to engineer high power laser-plasma sources for future applications.

AB - The production of intense X-ray and particle sources is one of the most remarkable aspects of high energy laser interaction with a solid target. Wide application of these laser-driven secondary sources requires a high yield, which is partially limited by the amount of laser energy absorbed by the target. Here, we report on the enhancement of laser absorption and X-ray and particle flux by target surface modifications. In comparison to targets with flat front surfaces, our experiments show exceptional laser-to-target performance for our novel cone-shaped silicon microstructures. The structures are manufactured via laser-induced surface structuring. Spectral and spatial studies of reflectance and X-ray generation reveal significant increases of the silicon Kα line and a boost of the overall X-ray intensity, while the amount of reflected light decreases. Also, the proton and electron yields are enhanced, but both temperatures remain comparable to those of flat foil targets. We support the experimental findings with 2D particle in cell simulations to identify the mechanisms responsible for the strong enhancement. Our results demonstrate how custom surface structures can be used to engineer high power laser-plasma sources for future applications.

UR - http://www.scopus.com/inward/record.url?scp=85083916314&partnerID=8YFLogxK

U2 - 10.1063/1.5125775

DO - 10.1063/1.5125775

M3 - Article

AN - SCOPUS:85083916314

SN - 1070-664X

VL - 27

JO - Physics of Plasmas

JF - Physics of Plasmas

IS - 4

M1 - 043106

ER -