RESULTS OF ANALYSIS OF Ti FOIL AFTER GLOW DISCHARGE WITH DEUTERIUM

In this study we report on the surface structure, distribution and isotopic composition of elements found on Ti cathodes before and after glow discharge in plasma, during which excess heat was produced. Irradiation was carried out with deuterium ions with a discharge voltage below 1000 volts, with a current of 10 to 20 mA. The analysis of the surface structure and of elemental composition of the Ti sample was carried out with a scanning electron microscope with Energy Dispersive X-ray Spectroscopy (EDS), which can detect impurities at concentrations as low as 0.2 atomic %. New metallic phase formation and newly present elements were revealed by the EDS method in several different, separate active spots on the cathode surface, with concentrations ranging from 0.3% up to 10 or 20% or more. Al, Mg, Br, Sr were found at ~0.3%, Rb ~0.4%, S ~1.0%, F ~10%, O >20%, Ni ~(0.3 20)%, Cr ~1.4%, Fe ~4.0%, Sn (~0.4 to ~5.0)% were detected by this method after the experiment and were not in the as-received sample before the experiment. The basic changes are observed in places of microexplosions, micromeltings and structural inhomogeneities. Investigation of the isotopic composition was carried out by Thermal Ionization Mass Spectroscopy (TIMS). Additional elements in a thin surface layer were found by this method when analysis was performed at 1900oC. The Ti cathode produced excess heat during glow discharge, estimated at 10 to 20% above input power. This suggests that the heat was caused by the formation of the observed new elements. It is necessary to note that excess heat was created by the processes in a sample having weight of 0.7 gram in a device weighing 5 kg. At the same time thermal losses with the water cooling of anode, losses through a quartz wall of the discharge chamber and the losses in metal flanges were not taken into account. In the experiments with other cathode materials (including Mo, W and Zr) under the same experimental conditions, no excess heat was observed and thermal losses were roughly 40%. INTRODUCTION Results from research with Pd cathodes irradiated by deuterium ions in glow discharge were published in previous papers [1-12.] We observed the weak gamma radiation, short-lived neutron bursts 2, , changes in surface structure and in the elemental and isotopic composition of Pd cathode (with purity 99.99% and 99.9%) 4, 5, 6, 7, 8 under deuterium ion irradiation. After irradiation, autoradiographs (X-ray film placed in contact with the samples) showed blackened areas. Not only were the autoradiographs placed in contact with irradiated Pd samples blackened, but also up to 7 Pd, Ti and Ag foils that were not directly irradiated, but which were located under an irradiated sample were blackened. In Pd samples, elements other than Pd increased by factors of 100 to 10,000. 6-8 EDS detected impurity elements in amounts ranging from 0.5% to 5%, which were not detected in the starting material. In accordance with the radiography analysis results the presence of the radioactive isotopes with various energies of emission on the Pd the cathode after glow discharge experiments had shown both high-energy and low-energy components. 5 The observed effects can be explained by a fusion-fission reaction on the cathode. That is, by an interaction of palladium with deuterium, and by the subsequent decay into more light elements. The majority of the elements which are detected by this method after irradiation, and which were not present before irradiation, were distributed on the boundaries of the grains and subgrains 2, 4, 5 and in local zones. The content of additional elements in such places was from about a tenth of a percent up to several percent. The content of the separate impurity elements in initial samples did not exceed 10 to 10 atomic % and that amount could not be detected by the microanalysis method. Groups of elements such as Sc, Ti, V; Ag, Cd, In; P, Cl, Br, Ge, As, Kr, Sr, Y, Ru, Xe were found out in Pd after an irradiation by ions of several different types (D, H, Ar, Ar + Xe), with varying amounts of the elements detected. 9 The integral sum of all impurity elements in Pd samples after irradiation by D, H, and Ar ions was estimated in the ratio 10:(2-3):1, accordingly. Elements with charge number Z = 26 31 (Fe, Cu, Zn, Ga) were observed by the MPA method after preferential irradiation by deuterium ions. The EDS and radiography results both indicate that nuclear transmutations occur intensively mainly on localized sites (hot spots). 6, 8 Different combinations of impurity elements found in different zones on the same samples were observed in the various characteristic spectrums for the same kind of ion 7, . The considerable changes of the isotope ratio B/B; C/C; Ni/Ni/Ni; Ca/Ca and Zr/Zr were observed and were published in paper [6]. The change of the isotope ratio for Ag:Ag from 1:1 in the initial unused Pd up to 3:1 and in some cases 9:1. This was described in Refs. 7 9. In this paper the changes of elemental and isotopic composition in the Ti sample with excess heat during deuterium ion irradiation in a glow discharge plasma is described in greater detail. EXPERIMENTAL METHOD The experimental procedure is described in detail in previous papers [2, 5, and 6]. A Ti (99.93 purity) cathode was irradiated with deuterium ions in a glow discharge, and then later examined. The density of the ion current was 10 to 20 mA/cm. The voltage of glow discharge was 300 850 V. The measurement system recorded current, the voltage of the discharge, gas pressure, the velocity of the gas stream, and the flow rate of the cathode cooling water. The temperature at the inlet and outlet of cooling water for both the cathode and the anode was recorded. The program used the inlet and outlet temperatures, flow rate, and input power to compute instantaneous input and output power, and any excess power. The program also keeps track of net input and output energy, and excess energy when present. The studies on the change of structure and elemental composition in the Ti cathode were carried out with using the scanning electronic microscope (JEOL, model JSM 6460-LV) and energy dispersion spectrometry (EDS) (Oxford Instrument, INCA). The quantitative analysis of the elemental content was performed using INCA software, version 4.02. Acquisition time per location was ~2 minutes. SEM accelerating voltage was 25 KeV. The area of spot analysis was 1 square micron at the site being analyzed; scanned areas were ~25 × 25 micron. The elements O, F, S, Na, Mg, Al, Ti, Cr, and Fe were determined by EDS on their K-lines; Mo, Br using their L-lines; and W using its M-line. The unused sample and a sample subjected to glow discharge in deuterium were analyzed in detail. Places with structural defects (such as flaws, tracks and projections); zones of such new formations such as blisters, craters, and micro-melted spots; needle structures, and typicaly “pure” sites of a surface without special changes were explored. Forty-seven sites were analyzed inside new formations and on “pure” sites of the surface of Ti foil after irradiation of deuterium ions and on ten sites on the surface of initial Ti. The most typical places of analyses and the content of additional elements in them with amounts more than 3are given on the appropriate illustrations and are accompanied by tables. The thickness of Ti foil was 0.05 mm; the titanium purity was 99.93%. Table 1 shows the impurities in the starting material, from the manufacturer’s certified data taken by X-ray diffraction.