CDS and SUMER

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CDS and SUMER Companions on SOHO

• Dave Pike and Richard Harrison

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Shared ancestry

• SOHO study team (inc. PL) - strong spectroscopic
  requirement
• GIS - Spectral/temperature coverage
• NIS Good spectral/spatial resolution
• Feb '85. NIS could have 7Å bands 500-1300 A. GIS
  descope or CDS
• Oct '85. It is generally agreed that lower
  spatial resolution would be acceptable for the
  shorter wavelengths.
• ? CDS VSP
• ? CDS (NIS/GIS) SUMER

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Early planning
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Performance

• CDS
• Large (100Å), fixed wavelength bands
• 150 Å ? 800 Å
• T 104 ? 106 K
• Spectral res. 500
• Spatial res. few arcsec
• Time res. lt1 sec
• Rigid planning

• SUMER
• Smaller (40Å), variable wavelength bands
• 500 Å ? 1600 Å
• T 104 ? 106 K
• Spectral res. 3 x 105
• High spatial res. 1.5"
• Typically 3 10 sec.
• SCL

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Solar-B EIS

• Smaller (40 Å), fixed wavelength bands
• 170 Å 290 Å
• T 105 ? 107 K
• Spectral resolution up to 1.5 x 104
• Spatial resolution lt 2"
• Time resolution lt 1 sec
• (Launch Aug 2006)

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CDS/SUMER "best practice"

• Speak same (spectroscopic) language, if at times
  with slightly different scientific accents
• Design driven by science requirements
• Blue and red books
• Early joint meetings for collaborative science
  and including calibration issues, ops modes, slit
  alignment etc.
• Creation and formalisation of JOPs
• Not only an example within SOHO, but carried
  forward to future projects

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Calibration

• Cleanliness ? calibration ? long-term and
  inter-comparison science studies
• Joint work with PTB, rocket under-flights,
  intercalibration JOPs
• Generous out-gassing period.

Nov 1983 - Philippe talks of cleanliness LiF
and MgF2 have known problems of deterioration
under 1 solar flux due to ionised
contaminants?
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Scientific collaboration

• 1989-2004 ADS abstracts.

293 papers CDSSOHO 351 papers SUMERSOHO
114 papers CDSSUMER
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Solar-B

• Three instruments spectrometer EIS
• EIS calibration, cleanliness program strongly
  influenced by CDS/SUMER SOHO experience
• Planning will be a CDS clone
• Solar-B operations based upon SOHO model
• Joint team discussions/plans taking place.

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Solar-B EIS calibration spectrum
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And finally, a message from The CDS and SUMER
teams have worked closely together since the
earliest stages of the SOHO proposal writing.
Indeed, Philippe worked alongside Bruce Patchett
in the definition of the mission. At one point,
we even discussed the possibility of providing a
single instrument. However, we decided on two
spectrometers, designed to work closely together,
to complement each other, and, as far as
scientific output is concerned, the CDS and SUMER
efforts have been a spectacular success for SOHO.
The success comes down to the foresight and skill
of a few individuals, such as Philippe. It has
been a pleasure to work with Philippe throughout
the whole SOHO era. He is a scientist who has
never lost sight of the true scientific drivers
behind the spectrometers and has inspired many to
exploit the mission as fully as possible.
Although most of the CDS team at RAL are not able
to enjoy the events of 18 November at IAS, we
send Philippe our best wishes, our thanks for
everything, and hope that he has a long and
enjoyable retirement.  
All the best,   Richard Harrison Jim Lang Andrzej
Fludra Dave Pike Peter Young Jeff Payne and all
the rest of the CDS/Solar Group at RAL