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Two Extreme Ultraviolet Detectors 30 to 150 A, 120 to 900 A

NSSDCA ID: 1969-046D-01

Mission Name: Vela 5A
Principal Investigator:Dr. W. H. Chambers


Two extreme ultraviolet (EUV) detectors were mounted in the apex positions of the spacecraft to measure solar EUV radiation. Both detectors used retarding potential analysis of photo electrons to obtain approximate spectral data of the solar flux. The XUO (X-ray Ultraviolet Open) detector was an open-window device designed to cover the wavelength range from 120 to 900 A using ten retarding potential steps from 7 to 250 V. The XUW (X-ray Ultraviolet Window) detector covered the range 30 to 150 A in ten analyzer steps from 75 to 1000 V. Both detectors were equipped with repeller grids for charged particle suppression. The acceptance aperture was 20 deg in one dimension, allowing approximately a 3-s scan of the sun, and +50 deg to -50 deg in the other dimension. The XUO detector was read out in real time only. The XUW was read out in real time, and it also stored data at about one fourth the rate of real-time data.

Alternate Names

  • Vela5A/TwoExtremeUltravioletDetectors30to150A,120to900A


  • Solar Physics: Ultraviolet

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Jack C. FullerOther InvestigatorLos Alamos National Laboratory
Dr. Walter E. KunzOther InvestigatorLos Alamos National Laboratory
Dr. W. H. ChambersPrincipal InvestigatorLos Alamos National Laboratory
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