True Beamsize - PRELIMINARY ASSESSMENT

The LWS beam has roughly the same FWHM (full width at half maximum) at every wavelength of 80". This is smaller than expected.

The figure below is almost hopelessly obscured but if you read along here it may come clear. The y-axis is labeled 0, 5, 10, 15, 20, 25%, while the x-axis is labeled 0", 50", 100", 150", 200". This is the lower wing of the LWS beam as mapped on Saturn at 25" spacings. The 10 detectors are shown here with the innermost detector being SW1 and the outermost detector being LW5. Note that the wings grow with wavelength to reach a radius at zero intensity of 100" or a diameter (FWZM: full width at zero maximum) of 200".

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Last update: August 1998

Steve Lord -- lord@heaven.ipac.caltech.edu