DEPENDENCES OF HELIUM RETENTION IN TUNGSTEN AND TANTALUM COATINGS IRRADIATED WITH He+ IONS ON FLUENCE AND TEMPERATURE

Abstract

The processes of helium accumulation and thermal desorption for tungsten and tantalum coatings deposited on a stainless-steel substrate with an intermediate titanium layer were studied at various temperatures of the samples when irradiated with He+ ions to various fluences. The dependences of the concentration of captured helium and the form of the spectra of its thermal desorption into vacuum were found both on the fluence of He+ ions and on the temperature of the samples upon irradiation. Possible mechanisms for the accumulation and thermal desorption of helium, as well as the formation of defects in the crystal lattice of the samples, are discussed.

Investigation of the Processes of Retention and Release of Implanted Deuterium and Helium Ions for Tungsten and Tantalum Coatings

“…This work authors in [37,47,49,53,54] studied effects of He + ions irradiation on tungsten coatings deposited on stainless steel substrates. The substrate 0.5 mm thick had the following composition: 20 Cr, 70 Fe, 8.5 Ni, and 1.5 Ti at %.…”

“…The substrate 0.5 mm thick had the following composition: 20 Cr, 70 Fe, 8.5 Ni, and 1.5 Ti at %. The W coatings were irradiated with He + ions to different fluences [47,49,54] and at different temperatures of bombarded target [37,53]. Processes of trapping, retention, and thermal desorption of implanted helium, as well as the formation and annealing of radiation defects in the crystal lattice of W coatings irradiated with 10 keV He + ions at the flux density of 3.0×10 17 m -2 •s -1 , were studied [47,49].…”

“…The influence of the samples temperature T o during He + ions irradiation to various fluences on the trapping, retention, and thermal desorption of ion-implanted helium in vacuum, and the formation and annealing of radiation defects in the crystal lattice of tungsten coatings was shown in [37,53]. The thickness of W coatings was ~1.0 µm.…”

“…This work authors studied the processes accompanying the implantation of D + or He + ions into tantalum coatings deposited on stainless steel substrates [36,37,53]. The trapping and retention of deuterium or helium and their thermal desorption into vacuum, formation and annealing of radiation damages in the crystal lattice were studied.…”

“…Helium thermal desorption from tantalum coating irradiated at T o = 290 K with He + ions to different fluences in the range 0.1×10 22 ≤ Ф ≤ 1.0×10 22 m -2 was studied in [53]. The He TDS spectra were shown in Figure 11b.…”