Previous abstract Next abstract

Session 67 - New Solar Instrumentation.
Oral session, Wednesday, June 12
Wisconsin Center,

[67.06] NIM-2 -- A Near Infrared Imaging Vector Magnetograph

D. Rabin, C. Keller, D. Jaksha (NSO/NOAO)

NIM-1 is a spectrograph-based Stokes polarimeter for measuring the strength and orientation of magnetic fields in the solar photosphere using two Zeeman-sensitive Fe I lines (g = 3 and g_geff = 1.53) near 1565 nm. NIM-2, now under construction, also uses these spectral lines but is based on a high-resolution Fabry-Perot etalon. NIM-2 will eliminate the image scanning and consequent spatial distortions of NIM-1 and will be compact and light enough to serve as a prototype for balloon or space instruments. The Queensgate etalon will provide a spectral resolving power of 10^5 over a 1-nm free spectral range. The initial detector will be the 256^2 InSb array shared with NIM-1, but NIM-2 is designed to accommodate a 512^2 or 1024^2 ``Aladdin'' InSb array. The data system, also shared with \mboxNIM-1, is being upgraded to handle the faster switching speed (\sim 8 ms) of improved liquid-crystal variable retarders.

NOAO is operated for the NSF by the Association of Universities for Research in Astronomy. Near-infrared magnetometry at NSO is supported by the the NASA Space Physics Division through the SRamp;T program in solar physics.

Program listing for Wednesday