2015-04-07 13:21:15.0 [mpmorahan] insert AltLabel (id: null text: Fast Plasma Instrument language code: en);
2015-04-07 13:19:24.0 [mpmorahan] insert Definition (id: null text: The Fast Plasma Investigation observes the fast-moving plasma. Incoming particles pass through a filter which cherry picks certain particle speeds and directions and allows them to pass through to a sensor plate. When an incoming particle hits the sensor plate, some million electrons come out the other side, so the instrument can detect the event. The whole process takes several nanoseconds. By separately measuring electrons and ions, and by filtering for specific energies, FPI can count the number of particles of each kind entering the instrument from a range of directions at different energies during any given time span. Past plasma detectors have relied on the spin of the spacecraft to gain a full view of its environment, but with only a journey of a fraction of a second through any given magnetic reconnection site, FPI must be much faster. Four sensors are used to detect the negatively charged electrons and another four for the positively charged ions. Each sensor is made of two spectrometers whose field of view is separated by 45 degrees, each of which can scan through a 45-degree arc for a larger panorama. All together the sensors can observe the entire sky. The box for each dual sensor and its components is as big as a small toaster oven, weighing in at about 15 pounds. In combination, FPI – consisting of the four dual electron spectrometers, the four dual ion spectrometers, and one data processing unit -- will produce a three-dimensional picture of the ion plasma every 150 milliseconds and of the electron plasma every 30 milliseconds. These frame rates are similar to those used in video and a factor of 100 times faster than what has been accomplished before for electrons. The dual electron spectrometers and the processing unit, or IDPU, were built at NASA Goddard. The dual ion spectrometers were built by Meisei Electric in Gunma, Japan, under the direction of the Institute of Space and Aeronautical Sciences, a part of the Japanese Aerospace Exploration Agency. language code: en);
Spectrometers
MMS FPI
The Fast Plasma Investigation observes the fast-moving plasma. Incoming particles pass through a filter which cherry picks certain particle speeds and directions and allows them to pass through to a sensor plate. When an incoming particle hits the sensor plate, some million electrons come out the other side, so the instrument can detect the event. The whole process takes several nanoseconds. By separately measuring electrons and ions, and by filtering for specific energies, FPI can count the number of particles of each kind entering the instrument from a range of directions at different energies during any given time span. Past plasma detectors have relied on the spin of the spacecraft to gain a full view of its environment, but with only a journey of a fraction of a second through any given magnetic reconnection site, FPI must be much faster. Four sensors are used to detect the negatively charged electrons and another four for the positively charged ions. Each sensor is made of two spectrometers whose field of view is separated by 45 degrees, each of which can scan through a 45-degree arc for a larger panorama. All together the sensors can observe the entire sky. The box for each dual sensor and its components is as big as a small toaster oven, weighing in at about 15 pounds. In combination, FPI – consisting of the four dual electron spectrometers, the four dual ion spectrometers, and one data processing unit -- will produce a three-dimensional picture of the ion plasma every 150 milliseconds and of the electron plasma every 30 milliseconds. These frame rates are similar to those used in video and a factor of 100 times faster than what has been accomplished before for electrons. The dual electron spectrometers and the processing unit, or IDPU, were built at NASA Goddard. The dual ion spectrometers were built by Meisei Electric in Gunma, Japan, under the direction of the Institute of Space and Aeronautical Sciences, a part of the Japanese Aerospace Exploration Agency.