First results of the SA Agulhas II mobile mini-neutron monitor: Instrumental characterization and environmental sensitivity

R.D. Strauss, F.J. Effenberger, S. Lotz, K. Herbst, H. Kruger, C. Diedericks, C. van der Merwe
Center for Space Research
North-West University (Potchefstroom Campus)
11 Hoffman Street, Potchefstroom, 2531
South Africa

A newly redesigned version of a mini-neutron monitor (NM), with updated and more sensitive electronics, was installed on the South African Antarctic research vessel, the SA Agulhas II, at the end of 2019. The 2019/2020 relief voyage to the SANAE (South African Antarctic base) research station was used to test the performance of the instrument. Results indicate that the new design, featuring a specially designed cradle with movement dampeners, worked well. However, due to the placement of the instrument, two unanticipated effects were observed: (i) A very strong temperature dependence at low temperatures and (ii) occasional high-frequency interference, possibly due to an ice radar antenna. Both of these effects are studied in detail, with preliminary findings presented here. Because of these effects, the mini-NM will be moved to a more suitable location onboard the ship soon and will, hopefully, provide long-term cosmic ray measurements in the southern oceans.