An empirical scaling for deuterium retention in co-deposited beryllium layers

Different mechanisms will contribute to tritium retention in ITER, amongst which co-deposition with materials from the plasma-facing components may be the main contributor. A systematic study of the influence of the deposition conditions (substrate temperature, deposition rate, energy of the incident particles) on the deuterium retention in co-deposited beryllium layers has been carried out in PISCES-B. The mechanism by which deuterium co-deposits with beryllium appears to be a combination of co-deposition and implantation, with a decreased retention for increased deposition rate and an increased retention for increased incident deuterium particles energy. A scaling equation is developed, providing a method to predict the retention in Be codeposits formed in PISCES-B as a function of the layer formation conditions. Using this equation, previously published data on retention in Be co-deposits are re-examined and relatively good agreement is found with the prediction of the scaling equation. PACS numbers: 52.40.Hf, 52.77.Dq An empirical scaling for deuterium retention in co-deposited beryllium layers 2