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Standard Radiation Environment Monitor

NSSDCA ID: 2004-006A-18

Mission Name: Rosetta
Principal Investigators:Dr. Peterri Nieminen
Principal Investigators:Mr. Hugh David Rees Evans


The Standard Radiation Environment Monitor (SREM) aboard the Rosetta spacecraft was designed to measure the energy and direction of high energy electrons and protons to study the radiation environment around the spacecraft. SREM comprises a 96 x 122 x 217 mm box that holds three solid state particle detectors, an internal dose monitor, and an internal temperature sensor. It has a mass of 2.5 kg and uses 2.5 W power.

The three detectors are silicon single-diode sensors designated D1, D2, and D3. Each detector has a opening angle of 20 degrees. Detectors D1 and D2 are combined in a telescopic configuration and can be used separately or in coincidence mode. They are separated by 1.7 mm of aluminum and o.7 mm of tantalum. The openings are covered with 2 mm of aluminum giving a cut-off energy of approximately 20 MeV for protons. The cut-off energy for coincident proton detections is about 43 MeV. D3 is a single diode for detection of protons and electrons. The entrance is covered with 0.7 mm of aluminum, which gives no cut-off for protons. The combination of inputs from the three detectors are fed into fifteen channels that measure electron energy from 0.5 MeV up, and proton energy from 10 MeV up.

Alternate Names

  • Rosetta/StandardRadiationEnvironmentMonitor
  • SREM

Facts in Brief

Mass: 2.5 kg
Power (avg): 2.5 W


  • Planetary Science: Small Bodies
  • Planetary Science: Fields and Particles

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Mr. Hugh David Rees EvansPrincipal InvestigatorESA-European Space Research and Technology
Dr. Peterri NieminenPrincipal InvestigatorESA-European Space Research and Technology

Selected References

  • Evans, H. D. R., et al., Results from the ESA SREM monitors and comparison with existing radiation belt models, Adv. Space Res., 42, No. 9, 1527-1537, doi:10.1016/j.asr.2008.03.022, Nov. 2008.
  • Mohammadzadeh, A., et al., The ESA Standard Radiation Environment Monitor program first results from PROBA-I and INTEGRAL, IEEE Trans. Nuclear Sci., 50, No. 6, 2272-2277, doi:10.1109/TNS.2003.821796, Dec. 2003.
  • McKenna-Lawlor, S., et al., Space Weather at Comet 67P/Churyumov–Gerasimenko Before its Perihelion, Earth, Moon and Planets, 117, No. 1, 1-22, doi:10.1007/s11038-015-9479-5, Mar. 2016.
  • Georgoulis, M. K., et al., Analysis and interpretation of inner-heliospheric SEP events with the ESA Standard Radiation Environment Monitor (SREM) onboard the INTEGRAL and Rosetta Missions, J. Space Weather Space Clim., 8, A40, 32 pp., doi:10.1051/swsc/2018027, Sept. 2018.
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