X-ray Absorption Spectral Analysis with a 9 V Battery X-ray Generator

Abstract

The measurements of X-ray absorption spectra (XAS) and Xray absorption fine structure (XAFS) have usually been performed by using a synchrotron radiation facility. It is widely believed that high intensity and monochromatized X-rays are necessary for XAS and XAFS experiments. In the present paper, however, we report K-edge XAS measurements of Ca contained in paper sheets using a dry electric battery XAS spectrometer.As one of the smaller X-ray sources, X-ray emission using the charging phenomenon of an insulator has been reported by several authors. [1][2][3][4] Recently, a novel and portable X-ray emitter using the charging phenomena of a pyroelectric crystal has become commercially available; its size is 15 mm in diameter and 10 mm in height. With a controller box that works off a 9 V dry electric battery, the full dimensions of this device are only 125 mm in length, 45 mm in width and 30 mm in height. Kawai et al. 5 reported X-ray fluorescence (XRF) analysis of metal oxides using this X-ray emitter. Ida et al. reported the XRF analysis of the small amount of Fe in aluminum foil 6 as well as the Cr analysis in steel. 7 They also performed XRF analysis of leathers, 8 glass and ceramics, 9 demonstrating the capability of this X-ray emitter as a source for a portable XRF instrument.The X-ray emitter used in the present measurement was a COOL-X (Amptek, Bedford, MA, USA), where LiTaO3 and Cu were used as the pyroelectric crystal and the target metal, respectively. Collision of electrons with the pyroelectric crystal as well as the metal target generated X-rays, which consisted of Cu K and Ta L lines and Bremsstrahlung radiation.Transmission X-rays were detected by a portable Si PIN detector XR-100CR (Amptek), of which the dimensions were the same as those of the COOL-X. One or two pieces of alkaline paper (name cards) with the thickness of 200 µm, which contained 2 mg/cm 2 (13 wt%) CaCO3 as filler and pigment, were measured. The geometry of the experiment is shown in Fig. 1. The distance between the X-ray emitter and the detector was 150 mm. The duration time for one spectrum was 400 s. In order to deliberately lower the detection of fluorescent X-rays from the sample, the sheet was placed close to the X-ray generator at a distance of 25 mm. The same sample was measured with two geometries: one for normal incidence (θ = 90˚) and the other the grazing incidence (θ = 30˚). Figure 2 shows the raw transmission spectra for no, one and two pieces of paper in the normal incident geometry. The spectrum for without paper was I0, where the main peaks were X-ray absorption spectral (XAS) analysis is performed with a combination of a 9 V dry electric battery X-ray generator and a portable Si PIN X-ray detector. The calcium K edge (4.0 keV) in paper is measured with a grazing incidence geometry, which suppressed the artifact due to the Kα X-ray fluorescence peak at 3.5 keV. The 9 V dry battery X-ray emitter is useful for portable XAS measurements. Fig. 2 Raw X-ray transmission spectra (I) of one and two pieces of paper wer...

A Simple X-Ray Emitter

“…Radioisotopes, small air-cooled X-ray tubes, or pyroelectric X-ray emitters are used. [11][12][13][14][15][16][17][18][19] Terasawa found that the charge-up of an insulator produced X-rays. 20 He invented an X-ray device, as shown in Fig.…”

Gray‐body approximation to continuous X‐ray spectra from scanning electron microscope

“…[6] The target was Cu, C, and Ni. The experiment was easy routine work as the usual SEM measurement but the beam was fixed at an area and EDX was measured.…”

Pyroelectric X‐ray application to X‐ray absorption and emission spectroscopies

“…Experimental geometry to measure X-ray absorption spectra (Reproduced from Ref. [13] ) by permission from the Japan Society for Analytical Chemistry.…”

“…The sensitivity difference in transition metals, [10] environmental, [11] and rice analyses [12] has been reported after the publication of Ref. [9] .The authors have also used the pyroelectric X-ray generator for the X-ray absorption spectrometry using an Si-PIN detector [13] and a superconducting energy dispersive X-ray detector. [14] The geometry to measure the X-ray absorption spectra is shown in Fig.…”