Isolating the detrapping of deuterium in heavy ion damaged tungsten via partial thermal desorption

JOURNAL OF NUCLEAR MATERIALS

卷:522

Article

Simmonds, M. J.¹  Schwarz-Selinger, T.²  Yu, J. H.¹  Baldwin, M. J.¹  Doerner, R. P.¹  Tynan, G. R.^1,3 

[1] Univ Calif San Diego, Ctr Energy Res, 9500 Gilman Dr, La Jolla, CA 92093 USA

[2] Max Planck Inst Plasma Phys, Boltzmannstr 2, D-85748 Garching, Germany

[3] Univ Calif San Diego, Dept Mech & Aerosp Engn MAE, 9500 Gilman Dr, La Jolla, CA 92093 USA

关键词: Tungsten;    Deuterium;    Retention;    Heavy ion damage;    Partial thermal desorption;    Peak-and-hold;    NRA;    TDS;   

DOI  :  10.1016/j.jnucmat.2019.05.016

来源: Elsevier

【 摘 要 】

Partial Thermal Desorption Spectrometry (pTDS) progressively depopulated trapped deuterium (D) from heavy-ion damaged tungsten (W) to determine spatial location and detrapping energies. W samples were prepared identically: 5 MeV Cu2+ damaging ions (0.12 peak dpa dose) before D-2 plasma loading (10(24) D/m(2) fluence) held at 373 K. Each sample reached one of six pTDS peak-and-hold temperatures. Nuclear Reaction Analysis (NRA) measured the D spatial profile remaining after pTDS, before final TDS. NRA and TDS measured total D retention were in good agreement. NRA displayed three zones of D-populated defects: (I) near-surface (below 0.1 mu m), (II) heavy-ion damage (peaked similar to 1 mu m), and (III) uniform intrinsic (bulk). D concentration in zone I reduced by similar to 97% in samples with pTDS at 597 K and higher, indicating near-surface traps have low detrapping energy. The Stopping and Range of Ions in Matter (SRIM) predicts a displacement profile for zone II that coincided with measured D profile for samples with pTDS at 597 K and higher. Samples prepared with pTDS below 597 K display a distinctly different D profile in zone II. The complete cycle of D-2 plasma loading, pTDS, NRA, and final TDS was modeled with Tritium Migration Analysis Program (TMAP) using a recently developed Pseudo Trap and Temperature Partition (PTTP) scheme. Differences in TDS profiles isolated traps that release between consecutive pTDS temperatures, demonstrating 6 distinct release peaks. The best fit was found with detrapping energies near 1.0,1.2,1.4,1.6, 1.8, and 1.9 eV. These results show that heating at 762 K for 2.5 h released similar to 99% of retained D in heavy-ion damaged W. (C) 2019 Elsevier B.V. All rights reserved.

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