# Characterization of an X-ray Source Generated by a Portable Low-Current X-Pinch
## 3 Results and Discussion
### X-ray Radiography
A further analysis of the results of Figure 8d shows that the overall transmission curve (dashed red) is lower in amplitude than the curve obtained at N = 32 (solid white); therefore, an OD value lower than 0.24 is expected. This behavior confirms that the Ti wire is not irradiated by a point-like source [32]. Figure 8b shows the perpendicular lineout of the Ti wire (see the relevant yellow marking line on Figure 8a). The maximum width S\({}_{\text{sw}}\) of the wire projection shadow is \(\sim\)400 \(\upmu\)m, as determined by the threshold level of the direct exposure area (N = 0 step). In addition, the minimum value is observed at the center of the transmission profile, and approximates the darkness of the area at step N = 8, resulting in a similar OD value of 0.36. Therefore, the transmission curve of step N = 8 can be approximated by a Ti sample with a thickness of 15 \(\upmu\)m, as the solid yellow curve indicates. Additionally, the overall OD for this equivalent sample Ti\({}_{\text{eq}}\) satisfies the limits set above, being in the range of 0.24 (N = 32)-0.26 (N = 16), as shown by the corresponding dashed yellow transmission curve in Figure 8d. Moreover, the size of the Ti\({}_{\text{eq}}\) is \(\sim\)137 \(\upmu\)m, as derived by excluding the wave nature of radiation [32], using the expression S\({}_{\text{FWHM}}\)/M of geometrical optics [25], where the FWHM width S\({}_{\text{FWHM}}\) of the shadow is \(\sim\)210 \(\upmu\)m, as shown in Figure 8b, and M = 1.53 is the magnification factor. The time-integrated X-ray source size is approximated by S = \(\Delta\)x/0.53, as discussed in Section 2, to be \(\sim\)330 \(\upmu\)m, where the spatial resolution \(\Delta\)x is \(\sim\)175 \(\upmu\)m, as illustrated by Figure 8b. In the literature, [PERSON] et al. [6] demonstrated, for an X-pinch device of 80 kA using two 5 \(\upmu\)m diameter tungsten wires, that the X-ray spectrum obtained via the X-ray pinhole camera has an increase in the X-ray yield observed at \(\sim\)9-10 keV, which is mainly attributed to the electron beam produced in X-pinches. In [20], [PERSON] et al. used a tungsten X-pinch configuration of 40 kA as an X-ray source, with a source size of less than 10 \(\upmu\)m, an X-ray yield of 60 mJ, and a pulse duration of 7 ns, and the produced photon energy was in the range of 800 eV to 5 keV. X-ray imaging is ideally suited for the detection of interior defects and contaminants in agricultural commodities [33]. _Bactrocera oleae_, the olive fruit fly, is the main insect pest of olives worldwide [34], and is a frequent cause of reduced olive oil quality. The presented and described X-pinch X-ray radiography was used to identify buried tunneling in olives. Figure 9a shows typical samples of olives and larvae of the olive fruit fly. The larvae feed inside the fruit, destroying the pulp, and allowing for the entry of secondary bacteria and fungi that rot the fruit and degrade the quality of the oil. The X-ray image in Figure 9b, obtained from the point-projection radiography method described above, clearly shows the extensive damage from olive fruit fly tunneling in the olive interior in the areas of the dashed black parallelograms, for the two olives at the bottom of the figure; the image of the larvae is also observed. Figure 8: (**a**) Time-integrated monochrome-negative radiograph (left) and its inverted X-ray-magnified area of interest (right). (**b**) Transverse lineout that indicates the shadow of the projected wire on the film. (**c**) OD in relation to the N numbers. (**d**) Total transmission curves, including the transmission of the film package.