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The Galileo Energetic Particles Detector


Galileo EPD Handbook


Chapter 1. Instrument Summary


Galileo T.A.C. Board


Source: Critical Design Review, Dec., 1987.


Design requirements:


  • Process start/stop pulses corresponding to flight times between 5 nS and 50 nS and output a voltage waveform representing time of flight
  • Reject all start pulse only (singles)events
  • Output:
    1. An AC coupled pulse with its positive lobe peak voltage representing time of flight
    2. A digital start pulse for all start input pulses
    3. A digital T.A.C. pulse for all valid T.A.C. events (start and stop)


Design Guidelines:


  • Adapt successful GIOTTO T.A.C. design concept for the Galileo EPD Time of Flight
  • Interface directly with existing Galileo EPD hardware
  • Use GIOTTO input hybrids to detect start/stop pulses down to a few mv
  • Reset/enable quickly following start only (singles) events
  • Expected total dose: 2.5 x 105 Rad Si

Figure 1-18. EPD TAC Electronics. Source: Critical Design Review, December 1987.
Figure 1-19. Schematic of EPD TAC board.  Source: Critical Design Review, December 1987.


Figure 1-20. Output Waveforms.



Figure 1-21 TAC output vs. TOF (22°C)
Figure 1-22  TAC output vs. TOF (-25°C, +50° C)



Next: CMS Analog Electronics (Pre-Challenger Information) 


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Updated 8/23/19, Cameron Crane


Manufacturer: The Galileo Spacecraft was manufactured by the Jet Propulsion Laboratory, Messerschmitt-Bölkow-Blohm, General Electric, and the Hughes Aircraft Company.

Mission Duration: Galileo was planned to have a mission duration of around 8 years, but was kept in operation for 13 years, 11 months, and 3 days, until it was destroyed in a controlled impact with Jupiter on September 21, 2003.

Destination: Galileo's destination was Jupiter and its moons, which it orbitted for 7 years, 9 months, and 13 days.