Behavior of hydrogen isotope retention in carbon implanted tungsten

To elucidate the C+ implantation effect on deuterium retention in tungsten, simultaneous C+ and D 2 + implantation was performed on tungsten. Deuterium desorption behavior for simultaneously implanted tungsten was compared with that the sequentially implanted tungsten. It was found that deuterium retention for the simultaneous case was lower than that for the sequential one, indicating that the sputtering of carbon and deuterium trapped by carbon would prevent the deuterium trapping. In addition, deuterium retention decreased with increasing C+/D+ ratio and deuterium trapping by carbon was not observed for high C+/D+ ratio. These facts indicate that the number of available traps in tungsten produced by simultaneous ion implantation would mainly control the deuterium retention in tungsten. However, for low C+/D+ ratios, deuterium trapping by carbon would be one of major trapping states.