Laser-based X-ray and electron source for X-ray fluorescence studies

Abstract

In this work we present a modification to conventional X-rays fluorescence using electrons as excitation source, and compare it with the traditional X-ray excitation for the study of pigments. For this purpose we have constructed a laser-based source capable to produce X-rays as well as electrons. Because of the large penetration depth of X-rays, the collected fluorescence signal is a combination of several material layers of the artwork under study. However electrons are stopped in the first layers allowing therefore a more superficial analysis. We show that the combination of both excitation sources can provide extremely valuable information about the structure of the artwork.

X-ray emission from a liquid curtain jet when irradiated by femtosecond laser pulses

“…The differences in the spectra for the low energy emission are due to a 1 cm methacrylate filter used for recording the spectrum of KBr. To obtain the efficiency of the liquid target, we can compare the K α energy conversion for KBr and for solid Cu targets which have been routinely used so far [18,19]. Figure 3 shows the spectra used for this comparison.…”

“…So far, different laser-based sources have been proposed but mostly relying on solid targets, and in the direction of achieving challenging performances rather than robustness and user-friendliness [13,14]. For example, nowadays one can find relatively simple setups capable to produce ultrashort bunches of X-rays and electrons using moderate laser intensities in the range of 10 16 -10 17 Wcm −2 [13][14][15][16][17][18][19][20][21]. Typically, a femtosecond laser is focalized into a solid target producing at the early stage of the pulse the ionization of the sample.…”

Laser-induced X-ray fluorescence and electron-based X-ray emission analysis of multi-layer material

“…So recently, the laser-induced X-ray uorescence measurement of artworks and cultural heritage has been reported. [9][10][11] Artworks and cultural heritage are often plated or painted over, so it is important to distinguish the information of material surface and interior; however, it is di cult to distinguish them owing to conventional X-ray tubes emitting monochromatic light, which have a larger penetration depth with several millimeters. So various experimental methods have been proposed for analyzing the interior of multi-layer materials.…”

“…A study that analyzed the X-ray uorescence of two layers of paint using laser-induced X-rays and electrons has been reported. [9] It is possible to proposed new economical technology, which is laser-induced X-ray and electron based uorescence of multi-layer alloy materials, not limited to the paints.…”

Quantitative laser-based x-ray fluorescence and particle-induced x-ray emission

“…The studied sample must be kept under vacuum and the probed thickness is only a few micrometers. The first reported use of a laser produced source for fluorescence analysis is the work by Valle Brozas et al in 2016 where a laser beam incident on a solid Cu target at ∼10 17 W cm −2 produced x-rays and electrons for the study of pigments [5]. First experimental demonstration of laser-PIXE using laser-accelerated protons has been obtained in 2017 by Barberio et al [6].…”