[en] We describe a novel plasma source developed at the Max Planck Institute for Physics that will be used for a proton driven plasma wakefield accelerator experiment at CERN. Rubidium vapor is confined in a 10 meter -long, 4 cm diameter, oil-heated stainless steel pipe. A laser pulse tunnel ionizes the vapor forming a 10-meter long, ∼1mm radius plasma with a range of densities around ∼10¹⁵cm⁻³. Access to the source is provided using custom manufactured fast valves. The source is designed to produce a plasma with a density uniformity of at least ∼0.2% during the beam–plasma interaction

[en] A method to accurately measure the density of Rb vapor is described. We plan on using this method for the Advanced Wakefield (AWAKE) (Assmann et al., 2014 [1]) project at CERN , which will be the world's first proton driven plasma wakefield experiment. The method is similar to the hook (Marlow, 1967 [2]) method and has been described in great detail in the work by Hill et al. (1986) [3]. In this method a cosine fit is applied to the interferogram to obtain a relative accuracy on the order of 1% for the vapor density–length product. A single-mode, fiber-based, Mach–Zenhder interferometer will be built and used near the ends of the 10 meter-long AWAKE plasma source to be able to make accurate relative density measurement between these two locations. This can then be used to infer the vapor density gradient along the AWAKE plasma source and also change it to the value desired for the plasma wakefield experiment. Here we describe the plan in detail and show preliminary results obtained using a prototype 8 cm long novel Rb vapor cell.

[en] Lι, Lα, Lβ and Lγ X-ray production cross-sections for 4 elements, 74≤Z≤90, at 10 different energies in the range 11-22 keV have been measured. The effect of Coster-Kronig transitions on fluorescence cross-sections for L X-ray line has been studied. Absolute values of L X-ray cross-sections have been calculated with incorporation of the enhancement due to the Coster-Kronig effect. The experimental enhancement factors tend to be smaller than those predicted by theory

[en] A method is presented to determine the coating thickness on a metallic substrate in energy dispersive X-ray fluorescence. The method is based on the measurement of incoherent scattered radiation. Energy dispersive XRF apparatus includes a filtered Am²⁴¹ point source and an Si(Li) detector with resolution 160 eV at 5.9 keV. The thicknesses of the coating materials found by the scattered radiation have been compared with thicknesses found by the gravimetric method. The obtained results show that there is good agreement between the present experimental results and the values of the gravimetric method within the estimated experimental error

No abstract available

[en] The experimental measurements of Lα/Lβ, La/Lγ, La/Lλ, Li/Lβ, Li/Lγ, Lβ/ Lγ intensity ratios were determined for three different cases by photoinozation consecutive L-subshells. The applied method relies on photoionization consecutive subshells and detection of the resolved fluorescence. The relative intensities in the 8 different elements with atomic number ranging from 66-90 at 15 different excitation energies in the interval 8.265-21.705 keV have been measured. A comparison is made of the experimental results with calculated values. The deflections of the experimental values from the theoretical values are in the range 4-13 percent

[en] Chemical shifts and full widths at half maximum intensity (FWHM) of Kα and Kβ_1,3 X-ray emission lines and differences of full widths at half maximum intensity (ΔFHWM) using metallic element as reference for these emission lines were measured for oxygen compounds of elements in the range 22≤Z≤29 with a Wavelength-Dispersive X-Ray Fluorescence Spectrometer (WDXRF). It was also found larger chemical shifts and FWHM for Kβ_1,3 lines than those of Kα ones. It should be noted that the magnitude of the chemical shifts increases with increasing number of ligand atom. (author)

[en] Average L shell fluorescence yield (ω-bar_L), average L shell Auger yields (α-bar_L) and the total L shell X-ray fluorescence (LXRF) cross sections (σ^x_L) at 30 keV have been calculated theoretically for the elements with 25 ≤ Ζ ≤ 101. These calculated values have been compared with the other experimental and theoretical values. (author)

[en] Highlights: ► Fe compounds are strongly correlated with the oxidation state. ► The chemical shift is proportional to the number of ligands. ► F compounds show higher chemical shifts than Cl compounds. ► Chemical shifts of the Kβ_1,3 line are higher than those of Kα line. - Abstract: Chemical shifts and full widths at half maximum intensity (FWHM) of Kα and Kβ_1,3 X-ray emission lines were measured for the following Fe compounds: Fe, FeCl₂, FeCl₃·6H₂O, FeF₂, FeF₂·4H₂O, FeF₃, FeF₃·3H₂O, FeO₃, FeS₂, FeSO₄. The measurements were performed with a wavelength-dispersive X-ray fluorescence spectrometry (WDXRF). It was found that the calculated results for Fe compounds are strongly correlated with the oxidation state. At the same time chemical effects for halogens compounds are generally more than that other compounds.

[en] The experimental measurements of Lα/Lβ, Lα/Lγ, Lα/Lι, Lι/Lβ, Lι/Lγ, Lβ/Lγ intensity ratios were determined for three different cases. In case 1, the excitation energy (E) is less than the binding energy of the L₂ subshell but sufficient to excite the L₃ subshell. In case 2, E is less than the binding energy of the L₁ subshell but sufficient to excite the L₂ subshell. In case 3, E is less than the binding energy of the K shell but sufficient to excite the L₁subshell. The applied method relies on photoionization of consecutive subshells and detection of the resolved fluorescence. The relative intensities in 8 different elements with atomic number ranging from 66-90 at 15 different excitation energies in the interval 8.265-21.705 keV have been measured. (author)