The CCRI News resource

Section III (neutron metrology) of the CCRI held its 27th meeting from 9th to 12th May 2023 at the BIPM in Sevres. 33 participants, 14 of them online, discussed during 3 full days the ongoing activities and future needs of neutron metrology.

One focus of the meeting was the discussion about ongoing and planned comparisons and the related long-term strategy within the CCRI(III). One conclusion of the discussions was that it is necessary to find and implement ways to limit the duration of key and supplementary comparisons organised within the CCRI(III). It was noted that the long delays, sometimes several years, in the completion of comparisons are mostly due to the increased logistical problems associated with sending around radioactive sources and transfer devices and it was decided for the upcoming CCRI(III).K8 comparison to run two transfer instruments in parallel in two separate groups.

Another issue raised during the meeting was the need to establish traceable metrology for neutron energies above 20 MeV, the upper limit of the well-established range. This is motivated by the need for dosimetry in mixed high energy radiation fields which is relevant for aircrew dosimetry, for space missions and for dosimetry of patients treated with modern forms of radiotherapy using protons and heavy ions. Therefore, it was decided to create a CCRI(III) task group “metrology for high energy neutrons” with the aim of increasing communication and interaction between metrology institutes, institutes with suitable facilities and stakeholders interested in this field through a potential workshop to be organised in 2024 or early 2025.