Particle Detectors
type: Concept

SEM-2
type: Concept
in scheme: instruments
definition: [Image and Text Source: NASA POES Project home page, http://goespoes.gsfc.nasa.gov/poes/instruments/sem.html ] The SEM/2 provides measurements to determine the intensity of the Earth’s radiation belts and the flux of charged particles at the satellite altitude. It provides knowledge of solar terrestrial phenomena and also provides warnings of solar wind occurrences that may impair long-range communications, high-altitude operations, damage to satellite circuits and solar panels, or cause changes in drag and magnetic torque on satellites. The SEM/2 consists of two separate sensor units and a common Data Processing Unit (DPU). The sensor units are the Total Energy Detector (TED) and the Medium Energy Proton and Electron Detector (MEPED). The DPU serves as the interface between the sensors and the spacecraft. The TED senses and quantifies the intensity in the sequentially selected energy bands. The particles of interest have energies ranging from 0.05 keV to 20 keV. The MEPED senses protons, electrons, and ions with energies from 30 keV to levels exceeding 6.9 MeV. Group: Instrument_Details Entry_ID: SEM-2 Group: Instrument_Identification Instrument_Category: Solar/Space Observing Instruments Instrument_Class: Particle Detectors Short_Name: SEM-2 Long_Name: Space Environment Monitor-2 End_Group Group: Instrument_Associated_Sensors Short_Name: TED Short_Name: MEPED End_Group Group: Associated_Platforms Short_Name: NOAA-19 Short_Name: NOAA-18 End_Group Online_Resource: http://goespoes.gsfc.nasa.gov/poes/instruments/sem.html Online_Resource: http://www.ncdc.noaa.gov/oa/pod-guide/ncdc/docs/klm/html/c3/sec3-5.htm Sample_Image: http://goespoes.gsfc.nasa.gov/poes/instruments/images/enlarged_sem.jpg Creation_Date: 2009-02-04 Group: Instrument_Logistics Instrument_Owner: USA/NASA Instrument_Owner: USA/NOAA End_Group End_Group