Liquid crystal polarimeter for solid-state imaging of solar vector magnetic fields. Final report, 1 October 1988-30 September 1992

Technical Report · Mon Sep 28 00:00:00 EDT 1992

OSTI ID:6625728

November, L J; Wilkins, L M

The Liquid Crystal Polarimeter (LCP) is a low-voltage complete Stokes polarimeter and spectral analyzer designed for measuring solar vector magnetic fields. The polarimeter consists of polarization and spectral analyzer sections each containing multiple commercially available nematic and ferro-electric liquid crystals that are modulated in phase at up to 31.5 kHz frequency. Used in conjunction with a Lyot birefringent filter and 2 CCDs, the system provides a complete polarization/spectral measurement for solid-state direct imaging of the vector magnetic flux, Doppler velocity, intensity, and line width in a spectral line. Simultaneous 2 CCD imaging gives reduced atmospheric seeing systematics, and automatic CCD gain and dark-current correction. The liquid-crystal design provides a considerable simplification to previous designs with greatly improved speed, sensitivity, reliability, and accuracy. The system is used with a universally tunable Lyot filter (of conventional rotating-element design) to provide sequential observations in a number of solar lines to permit calibration of field strength and measurements as a function of height in the solar atmosphere. An example vector magnetogram is shown as a proof of concept.

• Research Organization: Sacramento Peak Observatory, Sunspot, NM (United States)
• OSTI ID: 6625728
• Report Number(s): AD-A-260029/4/XAB
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
MAGNETIC FIELDS
IMAGES
POLARIMETERS
DESIGN
SOLAR ATMOSPHERE
SPECTRA
BIREFRINGENCE
CHARGE-COUPLED DEVICES
LINE WIDTHS
LIQUID CRYSTALS
POLARIZATION
SOLAR ACTIVITY
SOLID STATE PHYSICS
ATMOSPHERES
CRYSTALS
FLUIDS
LIQUIDS
PHYSICS
REFRACTION
SEMICONDUCTOR DEVICES
440800* - Miscellaneous Instrumentation- (1990-)
661320 - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)