Radi-N2 Neutron Field Study (Radi-N2) - 12.23.14

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Radi-N2 Neutron Field Study (Radi-N2) is a follow on investigation designed to characterize the neutron radiation environment aboard the International Space Station (ISS). Eight neutron “bubble detectors” produced by the Canadian company Bubble Technology Industries are attached to fixed locations inside the ISS, including one carried by a crewmember. The objective of this investigation is to better characterize the ISS neutron environment and define the risk posed to the crewmembers’ health and provide the data necessary to develop advanced protective measures for future space flight.

Science Results for Everyone
Information Pending

The following content was provided by Martin B. Smith, Leena Tomi, and is maintained in a database by the ISS Program Science Office.

Experiment Details


Principal Investigator(s)

  • Martin B. Smith, Bubble Technology Industries Inc, Chalk River, Ontario, Canada
  • Leena Tomi, Canadian Space Agency, Saint Hubert, Quebec, Canada

  • Co-Investigator(s)/Collaborator(s)
  • Vyacheslav A. Shurshakov, Institute of Biomedical Problems, Moscow, Russia

  • Developer(s)
    Bubble Technology Industries, Incorporated, Chalk River, Ontario, Canada

    Sponsoring Space Agency
    Canadian Space Agency (CSA)

    Sponsoring Organization
    Information Pending

    Research Benefits
    Information Pending

    ISS Expedition Duration
    September 2012 - Ongoing

    Expeditions Assigned

    Previous ISS Missions
    Radi-N1 Increment 20/21

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    Experiment Description

    Research Overview

    Study is supported by the ISS Radiation Health Working Group in its aim to better characterize the neutron environment aboard the ISS. Better understanding of the neutron contribution will assist in the development of more effective countermeasures. Neutrons are of particular interest to radiation health and protection as neutrons have higher radiation Quality Factor (QF) and since they have not been well characterized by operational monitoring. It has been recognized that neutrons make up a significant fraction (10-30%) of the biologically effective radiation exposure in low-Earth orbit (i.e. International Space Station).

    • Study is a continuation of Radi-N1 done in Increment 20/21, and will repeat the measurements in the same/equivalent locations aboard the ISS: USLab, JEM (Nominal), COLUMBUS, Node2 (Reserve) The additional data will increase the statistical accuracy of the neutron measurements and also allow comparison of neutron fields at different periods of the solar cycle.

    • Results of Radi-N 1 & 2 study will allow better understanding of radiation environment aboard the International Space Station. The utilization of newly developed Bubble Detector Spectrometer will help characterize the neutron spectrum on board, and measurements in different ISS locations will provide a means of assessing the neutron field symmetry in different modules of the Station. Measuring the average dose within different segments of ISS will help with development of radiation protection plan for future missions.

    Information Pending

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    Space Applications

    Neutrons are nuclear "splinters" produced when cosmic rays strike the atoms of a spacecraft or even the human body. Earlier experiments with Matroshka-R, a "phantom" body, revealed that astronauts absorb larger doses of neutron radiation than expected, possibly from cosmic rays striking atoms in their bodies. Mapping across the ISS will help reveal neutron sources and exposure dangers.

    Earth Applications

    Because they carry no electrical charge, neutrons have greater potential to penetrate the body and damage tissue. Radi-N2 will help doctors understand better the connections between neutron radiation and DNA damage and mutation rates, cataracts that affect some astronauts, and other radiation health issues.

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    Operational Requirements
    Information Pending

    Operational Protocols
    Information Pending

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    Results/More Information
    Information Pending

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    Results Publications

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    Ground Based Results Publications

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    ISS Patents

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    Related Publications

      El-Jaby S, Tomi L, Sihver L, Sato T, Richardson RB, Lewis BJ.  Method for the prediction of the effective dose equivalent to the crew of the International Space Station. Advances in Space Research. 2014 March; 53(5): 810-817. DOI: 10.1016/j.asr.2013.12.022.

      El-Jaby S, Lewis BJ, Tomi L.  A model for predicting the radiation exposure for mission planning aboard the international space station. Advances in Space Research. 2014 April; 53(7): 1125-1134. DOI: 10.1016/j.asr.2013.10.006.

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    Related Websites

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