The high-flux effect on deuterium retention in TiC and TaC doped tungsten at high temperatures

• Published in: Journal of nuclear materials Vol. 494; pp. 211 - 218
• Main Authors: Zibrov, Mikhail, Bystrov, Kirill, Mayer, Matej, Morgan, Thomas W., Kurishita, Hiroaki
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-10-2017; Elsevier BV
• Subjects: Blistering; Desorption; Deuterium; Deuterium retention; Fluxes; High temperature; Inventories; Mechanical properties; Plasma; Precipitates; Spectroscopy; Surface modifications; Tantalum; Tantalum carbide; Thermal desorption; Thermal desorption spectroscopy; Titanium carbide; Tungsten; Blistering; Surface modifications; Thermal desorption; Tungsten; Deuterium retention
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2017.07.028

Samples made of tungsten (W) doped either with titanium carbide (W-1.1TiC) or tantalum carbide (W-3.3TaC) were exposed to a low-energy (40 eV/D), high-flux (1.8–5 × 1023 D/m2s) deuterium (D) plasma at temperatures of about800 K, 1050 K, and 1250 K to a fluence of about1 × 1027 D/m2. The deuterium (D) inventory in the samples was examined by nuclear reaction analysis and thermal desorption spectroscopy. At 800 K the D bulk concentrations and total D inventories in W-1.1TiC and W-3.3TaC were more than one order of magnitude higher compared to that in pure polycrystalline W. At 1050 K and 1250 K the D concentrations in all types of samples were very low (≤10−5 at. fr.); however the D inventories in W-1.1TiC were significantly higher compared to those in W-3.3TaC and pure W. It is suggested that D trapping inside the carbide precipitates and at their boundaries is essential at high temperatures and high incident fluxes, especially in W-1.1TiC.
•Carbide precipitates in TiC and TaC doped tungsten can provide high-energy trapping sites for deuterium.•The concentration of traps in these materials is higher as compared to pure tungsten.•The trapped deuterium concentration depends on ion flux at high temperatures.•At high ion fluxes TiC doped tungsten is able to retain deuterium at temperatures up to about 1250 K.