Impact of helium implantation and ion-induced damage on reflectivity of molybdenum mirrors

• Molybdenum mirrors were irradiated with Mo and He ions to simulate the effect of neutron irradiation on diagnostic first mirrors in next-generation fusion devices. Up to 30 dpa were produced under molybdenum irradiation leading to a slight decrease of reflectivity in the near infrared range. After 3×1017 cm-2 of helium irradiation, reflectivity decreased by up to 20%. Combined irradiation by helium and molybdenum led to similar effects on reflectivity as irradiation with helium alone. Ion beam analysis showed that only 7% of the implanted helium was retained in the first 40nm layer of the mirror. The structure of the near-surface layer after irradiation was studied with scanning transmission electron microscopy and the extent and size distribution of helium bubbles was documented. The consequences of ion-induced damage on the performance of diagnostic components are discussed.

Ämnesord

NATURVETENSKAP  -- Fysik -- Acceleratorfysik och instrumentering (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Accelerator Physics and Instrumentation (hsv//eng)

NATURVETENSKAP  -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Nyckelord

Diagnostic mirrors

Fusion

Helium

Ion-induced damage

Molybdenum

Fusion reactions

High resolution transmission electron microscopy

Infrared devices

Ion beams

Ions

Irradiation

Mirrors

Radiation

Reflection

Scanning electron microscopy

Transmission electron microscopy

Helium implantation

Helium irradiation

Implanted helium

Ion beam analysis

Near-infrared range

Near-surface layers

Scanning transmission electron microscopy

Neutron irradiation

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)