Comparative study of laser-induced plasma emission of hydrogen from zircaloy-2 samples in atmospheric and low pressure ambient helium gas

Deuterium analysis in zircaloy using ps laser-induced low pressure plasma

“…On the other hand, the D and H emission intensities show significantly slower decline. This phenomenon of sustained emission of H and D has been observed previously and explained as being indicative of the effective role of the helium metastable excited state in sustaining the excitation processes of H and D. 16,17,[19][20][21][22] This is in a way corroborated by the concomitant observation of the He I 667.8 nm emission, as shown in Fig. 4, which implies the sustained presence of the helium atoms in their metastable excited state.…”

“…1. The chamber used is the same special cylindrical chamber of 115 mm inner diameter employed in our previous experiments 16,17,[19][20][21][22] It was designed with several entry ports to allow the control and monitoring of the specific conditions inside the chamber as needed by the experiment. The major modification of the previous experimental setup is the replacement of the nano-second (ns) laser by a pico-second (ps) laser (Nd-YAG, EKSPLA, model PL 2143, 1064 nm, 20 ps, maximum energy of 30 mJ) which was also operated in the Q-sw mode at 10 Hz repetition rate with the laser output energy fixed at the much lower level of 7 mJ.…”

“…The high purity helium gas (Air Liquid, 5 N) was thereafter introduced into the chamber until a pressure of 1.3 kPa was reached at a constant flow of 2 l/min. The chamber temperature chosen for the heating process in this experiment was lower compared to that used previously (200 C), 19,20 because the deuterium became completely outgassed when the temperature was raised to 200 C due to the weaker bonding energy of Zr-D as compared to Zr-H. The gas pressure of helium 1.3 kPa and the above-mentioned chamber temperature (150 C) were henceforth kept constant throughout the experiment.…”

“…Electronic mail: kurnia18@cbn.net.id. 0021-8979/2011/110(6)/063301/6/$30.00 V C 2011 American Institute of Physics 110, 063301-1 using helium ambient gas, on the reduction of H emission line broadening, the suppression of intensity diminution, and reduction of spectral interfering effect of H from surrounding water molecules, 19,20 which are promising for the further development of reliable and sensitive spectrochemical analysis of hydrogen.…”

The role of He in enhancing the intensity and lifetime of H and D emissions from laser-induced atmospheric-pressure plasma

“…tensity and a reduction in the Stark broadening effect 13 were reported. In addition to exhibiting a similar enhancement, a later experiment on a zircaloy sample also produced hydrogen emission with a longer lifetime, 14 which was suggested to indicate the role of He atoms in their metastable excited state. Despite the major practical and scientific significance of these experimental observations, the detailed elucidation of the underlying physical mechanism involving the energy transfer process still remains a challenging subject of research.…”