Project Title

Collaborative Research: The Simpson Neutron Monitor Network

Summary

Event Number:
A-118-S
NSF / OPP Award 2112437

Program Director:
Dr. Marion Dierickx

ASC POC/Implementer:
Marissa Goerke / Sheryl Seagraves

Principal Investigator(s)

Dr. Surujhdeo Seunarine
surujhdeo.seunarine@uwrf.edu
University of Wisconsin River Falls
Department of Physics
River Falls, Wisconsin

Project Web Site:
https://neutronm.bartol.udel.edu/realtime/southpole.html

Location

Supporting Stations: South Pole Station
Research Locations: South Pole Station, B2 Laboratory

Description

Neutron monitors have been operating at the South Pole with few interruptions since 1964. They indirectly detect galactic cosmic rays and solar energetic particles. The station’s high altitude and low-geomagnetic cutoff provide a unique, scientifically desirable location to observe moderate energy (1-10 gigaelectronvolts [GeV]) solar and galactic cosmic rays, as well as a key low-geomagnetic cutoff dataset for the worldwide network of neutron monitors. Operating a neutron-monitor suite at South Pole Station, this project aims to increase understanding of solar energetic particles using neutron monitor data, complemented by data from the nearby IceTop air shower detector. Another focus area is understanding the nature of multiple coincident particles observed in the neutron monitors, which extend the reach of the South Pole neutron monitor as a single station capable of doing cosmic ray spectral studies. Also central to the research is understanding the response of these detectors to the radiation environment of the South Pole, particularly in determining the cause of the decline in cosmic ray intensity at the South Pole over the last 50 years. Understanding this decline is important because cosmic rays produce radionuclides such as beryllium-10 that become trapped in the ice and are used to determine ice-core ages and precipitation levels over Earth's polar regions. An understanding of the production rate is vital to interpreting these data. The South Pole neutron monitor is a key instrument of the Simpson Neutron Monitor Network.

Field Season Overview

On-site fieldwork for the 2025-26 season includes raising the outdoor equipment platform above the surrounding snow level to mitigate current impacts to measurements. One person will deploy to coordinate and manage detectors during the platform raise, in addition to performing annual maintenance and calibration operations.

Maintenance work will include replacing heaters on the outdoor monitors and further reconfiguration of the bare neutron counters on the B2 Mezzanine, which are susceptible to microphonics and produce especially noisy data when activity on the Mezzanine increases during the field season.

In addition, research associate support will be provided throughout the year for routine monitoring and maintenance of equipment, including observation of the equipment on the outdoor platform and in the B2 Lab to ensure it is in normal operating mode; shutdown and restart of software and hardware as needed; and communication with the project's principal investigator and other personnel. Research associates will also support any required upgrades to electronics boards, mechanical stabilization of the bare neutron monitor on the Mezzanine level of the B2 Lab, and heater and other checks on the outdoor equipment.

Deploying Team Members