The measurements made here confirm those made by the manufacturer of the QMC100 (ALMA band 3) and QMC230 (ALMA band 6) windows, and show that the in-band loss (absorption and reflection) of the windows is of order of 2-5% over the whole band. Thus, at least one commercial source has been found for vacuum windows for ALMA receivers. The manufacturer believes that they can supply similar windows for all ALMA bands.
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Last modified: December 12, 2000
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