‘Radiation to Materials’ at CERN

Irradiation tests are continuously needed at the
European Organization for Nuclear Research (CERN), to experimentally
assess the radiation tolerance of commercial nonmetallic
materials for use in high-radiation areas. The ’Radiation
to Materials’ R2M activity organizes such tests and provides
expertise in the interpretation of results, for the design and
upgrade of devices absorbing critical doses during their lifetime.
The various activities covered by the R2M are presented. Up
to ten irradiation tests per year are organized in external 60Co
facilities, in which samples absorb up to several MGy of gamma
dose at dose rates in the kGy/h range. Cables, O-rings, lubricants,
glues, optical materials, and insulators are examples of possible
tested materials. In parallel, selected samples are irradiated in
a mixed neutron and gamma irradiation station built close to
the Neutron Time-Of-Flight facility. Dedicated research studies,
mainly focused on oil, greases and elastomeric O-rings, are
being performed to deepen the understanding of radiation effects
in these critical materials. As an example, the mechanical
and structural characterization of two elastomeric EPDM-based
commercial materials irradiated in gamma radiation up to 3 MGy
of dose is presented.