Voyager In Space


Galaxy Banner Image

Voyager LECP Data Analysis Handbook


Calibrations and Channel Definitions


The Voyager (MJS) LECP Pulse Height Analyzer (PHA)


(Document Source: A. F. Hogrefe, 28 July, 1977, EME-77-159)




The Applied Physics Laboratory S1P Group has an experiment to monitor Low Energy Charged Particles during the Voyager '77 (originally Mariner-Jupiter-Saturn) mission. The two spacecraft probes in this series provide a unique opportunity for measurement of both the interplanetary solar winds and the local radiation fields of the two planets. The LECP is the latest in a series designed by S1P and includes an elementary Pulse Height Analyzer for improved particle identification and energy resolution. EME was responsible for the design and qualification of this Pulse Height Analyzer. Concepts, specifications and test results are detailed herein.


The LECP was conceived and designed by several individuals. The Pulse Height Analyzer portion uses some designs and concepts developed elsewhere in the experiment. The successful interface with the analog and digital portions of the experiment was due to the patience and perseverance of all concerned. Supporting help at the board and test level was provided by S1P and EEF fabrication personnel. Mechanical design and drafting was accomplished by S1P while the hybrid designs were developed within EME. JPL provided assistance in radiation hardening the design and maintaining highly reliable components for production. The attached references detail some of the contributions and the efforts of all concerned have been much appreciated.




  1. The Basic Pulse Height Analyzer
  2. LEPT Mode
  3. LEMPA Mode
  4. Circuit Detail
  5. Tailoring the Pulse Height Analyzer
  6. Specifications for the LECP Pulse Height Analyzer
  7. Calibration Table for Pulse Height Analyzers
  8. References
  9. Appendix A - PHA Test Set
  10. Appendix B - Discrete Parts List



Return to Calibrations main page.

Return to Voyager LECP Data Analysis Handbook Table of Contents.
Return to Fundamental Technologies Home Page.

Updated 8/9/19, Cameron Crane


Days: Hours: Minutes: Seconds

*Since official launch
September 5, 1977, 12:56:00:00 UTC


Days: Hours: Minutes: Seconds

*Since official launch
August 20, 1977, 14:29:00:00 UTC


Manufacturer: Voyagers 1 and 2 were built in the Jet Propulsion Laboratory in Southern California.

Mission Duration: 40+ years have elapsed for both Voyager 1 and Voyager 2 (both are ongoing).

Destination: Their original destinations were Saturn and Jupiter. Their current destination is interstellar space.