Transient field measurements on light and heavy ions in amorphous iron-boron compounds

Measurements of transient magnetic fields (TF) were performed for the first time in the amorphous compounds of Fe₈₀B₂₀ and Fe₈₅B₁₅ for ²⁴Mg(2⁺), ²⁸Si(2⁺), ⁴⁸Ti(2⁺) and ⁵⁶Fe(2⁺) probe ions employing light and heavy ion beams. The motivation for these experiments was to investigate whether ion beam induced attenuations of TF are substantially weaker in these materials than in crystalline Fe. This expectation was indeed satisfied. The attenuations observed were found to be smaller at least by a factor of 2.     

The use of X‐ray interaction data to differentiate malignant from normal breast tissue at surgical margins and biopsy analysis

X‐ray interaction data, including measuring bio‐metal levels and scattering characteristics, are being shown to be a possible discriminating variable in the classification of human tissues. However, a major concern when using X‐ray interaction data in breast cancer material is that the samples are rarely 100% tumour because of the invasive nature of the disease. The work reported here includes a methodology to help overcome this limitation as the experimental protocol includes mapping the data to histological analysis of the measured samples. This work has shown how important it is to relate the measured X‐ray parameters to the histology of the samples, particularly the clinical information that describes the percentage of tumour within each sample. Levels of K, Ca, Zn, Fe, Cu, Br and Rb were evaluated using X‐ray fluorescence and compared between tumour breast tissue and normal surrounding breast tissue. The coherent scattering properties of each sample were also examined using an angular dispersive X‐ray diffraction technique. Multivariate modelling using soft independent modelling of class analogy was used to classify samples kept out of the modelling procedure. A significant increase (p < 0.01) in the levels of Rb, Zn and K was found in the tumour samples. The levels of these elements show a correlation with the percentage of tumour reported to be present in a given sample. The results of classifying unknown tissue samples are presented using two‐class and three‐class models that help to reveal the importance of sample histology in studies involving breast cancers. Copyright © 2013 John Wiley & Sons, Ltd.     

Transient field measurements on56Fe- and80Se-ions using segmented Fe-layers

Measurements of transient magnetic fields (TF) were performed on swift heavy ions of⁵⁶Fe and⁸⁰Se, with Coulomb excitation of their first 2⁺ state as probe, traversing thin Fe layers with segmented and unsegmented structures. The 50 µm×50 µm squares of the segments were accomplished applying the techniques of photolithography and ion etching. The magnitude of the TF deduced clearly shows that by segmentation of the targets the ion beam induced attentuations can be eliminated. This finding has direct applications tog-factor measurements.     

Radioxenon net count calculations revisited

To obtain the relationship between radon solubility and temperature, salinity, and pH of radon-bearing water in in situ leaching uranium mines, an experimental device for measuring the radon solubility in water was designed and manufactured. According to the range of temperature range, salinity, and pH of radon-containing radioactive water from in situ leaching mines in China, aqueous radon solubilities at different temperatures and salinities were determined using an orthogonal design and, concurrently, radon solubilities at different pH also determined. An empirical equation for estimating the radon solubility in radioactive water containing radon in uranium mining and metallurgy is proposed.

     

Hyperfine interaction studies on swift O-ions emerging with polarized electrons from ferromagnetic layers into vacuum

A precision plunger set-up was used to determine in time-differential measurements of hyperfine interactions the degree of polarization of 1s- and 2s-electrons in H- and Li-like oxygen ions on their emergence from magnetized Ni- and Gd-layers into vacuum. In addition a time-integral measurement with Fe-layers served to obtain the polarization of 2s-electrons only. For all three ferromagnetic materials the degree of polarization of 2s-electrons is found to be twice as large as for 1s-electrons. The data are discussed in the context of transient magnetic fields and their underlying polarization mechanism.     

On the ion beam stopping power dependence of transient magnetic fields in Fe- and Gd-hosts

Ion-beam induced attenuations of transient magnetic fields have been further studied in measurements on high-velocity²⁴Mg- and²⁸Si-ions as well as low-velocity⁴⁸Ti-ions using energetic beams of Ti- and Br-ions. Further evidence for the stopping power dependence of the attenuations is found; more data in the threshold region of Fe-host support earlier observations. In Gd-host the attenuations are again weaker pronounced than in Fe in accordance with previous data.