Contamination control and material screening for the extreme ultraviolet coronal diagnostic spectrometer on SOHO

Physics – Optics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

3

Scientific paper

The Coronal Diagnostic Spectrometer (CDS) to be flown on the Solar Heliospheric Observatory (SOHO) satellite makes use of both grazing and normal incidence optics operating in the extreme ultraviolet wavelength range from 15 to 80 nm. Its optical components include a Wolter Schwartzschild type 2 telescope and grazing and normal incidence reflective diffraction gratings. The instrument is thus highly sensitive to contamination both from particulate debris of a kind readily controlled by use of clean rooms, but also from offgassed and outgassed molecular species arising from materials used in clean room construction and from components within the instrument itself. We describe the contamination control protocol used to constrain the contamination, both particulate and molecular, to levels that will maintain the instrument performance for the expected duration of the SOHO mission. We also describe and report some results from a parallel activity in which we have screened materials for inclusion in CDS construction, by making use of a purpose built ultra high vacuum system to provide a contamination source and surface science diagnostics. In this apparatus material samples are held at elevated temperature to expel, in a controlled manner, outgas products which are allowed to contaminate previously characterized gold coated witness mirrors. The outgas products being monitored by residual gas analysis and a quartz crystal microbalance. The contaminated witness mirror surfaces are chemically characterized without breaking vacuum using X-ray photoelectron spectroscopy (XPS), and the change in reflectivity at ultraviolet wavelengths is also measured in the same apparatus.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Contamination control and material screening for the extreme ultraviolet coronal diagnostic spectrometer on SOHO does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Contamination control and material screening for the extreme ultraviolet coronal diagnostic spectrometer on SOHO, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Contamination control and material screening for the extreme ultraviolet coronal diagnostic spectrometer on SOHO will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1712893

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.