Real-time measurement of low-energy-range neutron spectra on board the space shuttle STS-89 (S/MM-8)

• Published in: Radiation measurements Vol. 33; no. 3; pp. 321 - 333
• Main Authors: Matsumoto, H., Goka, T., Koga, K., Iwai, S., Uehara, T., Sato, O., Takagi, S.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-06-2001; Elsevier
• Subjects: Aluminum; Atlantic Ocean; Earth sciences; Earth, ocean, space; Elementary Particle Interactions; Elementary Particles; Evaluation Studies as Topic; Exact sciences and technology; Fast Neutrons; Gadolinium; Geochronology; Isotope geochemistry. Geochronology; Monte Carlo Method; Neutrons; Polyethylene; Protons; Radiation Dosage; Radiation Monitoring - instrumentation; Solar Activity; South America; Space Flight - instrumentation; Spacecraft - instrumentation; South America; Atlantic Ocean; detection; instruments; cosmic rays; space programs; particles; neutrons; energy
• ISSN: 1350-4487; 1879-0925
• DOI: 10.1016/S1350-4487(00)00157-8

We have developed a real-time, Bonner Ball-type (neutron energy range is from thermal to 15 MeV) neutron spectral measurement system (Bonner Ball Neutron Detector (BBND)) for use on board the International Space Station (ISS). From measurements taken inside STS-89 (S/MM-8), we successfully distinguished neutrons from protons and other particles in a mixed radiation field; a task hitherto considered difficult. Although the experimental period was short, only 3.5 days (January 24–27, 1998), we were able to obtain energy spectral data and the Earth's neutron dose-equivalent map for the ISS orbital conditions (altitude 400 km, orbit inclination angle 51.6°). A method for calculating the neutron energy spectrum and compensating for the particle interaction with the sensors is also described in detail.