@prefix skos: . skos:definition """The second instrument of PVSO is the Magneto Optical Filter. This instrument is still under construction but its first phase is currently completed and operational. In this phase the MOF is able to record intensitygrams of the sun in the potassium 769.9nm line. With the completion of the second phase the MOF will be able to acquire simultaneous dopplergrams and magnetograms of the surface of the Sun. In the curent configuration, a telescope is used to form an image of a solar region of interest on a CCD camera. The MOF is placed between the telescope and the camera and filters the light by isolating the potassium line. The hearth of the MOF is a glass cell that contains potassium vapor, which is placed in a longitudinal magnetic field. The light which enters the cell passes first trough a linear polarizer which transform the randomly polarized light into linear polarized light. In the presence of the magnetic field, the vapor will alter the polarization state of the potassium line. A second polarizer with the transmission axis perpendicular to the first is placed at the exit, blocking all the light but that modified by the vapor. The output consists of an image of the sun in the two wings of the potassium line. A second vapor cell, called the wing selector, will be added to the filter in the near future and will provide images of the Sun's velocity and magnetic fields. Additional information available at "http://www.pvamu.edu/cps/info/bottom" [Summary provided by Prairie View A&M University]"""@en ; skos:prefLabel "MAGNETO OPTICAL FILTER"@en ; skos:inScheme ; skos:broader ; a skos:Concept . skos:prefLabel "Spectrometers"@en ; a skos:Concept ; skos:narrower .