• From the point of view of continuum, the feeds should be native circular. With no special provisions other than that (for instance, there is no need for the receiver to be particularly stable since you get rid of the DC level), the existing GBT spectrometer will allow sensitive, broadband measurements of linear polarization. This would be a unique and outstanding capability to study the polarization of spinning dust -- BrianMason - 03 Oct 2007

• From the point of view of Zeeman studies, the feeds should be native linear. It has been suggested that CCS (2,1-1,0) at 22.344 GHz may be important for tracing the magnetic field in dense gas (especially in low mass star forming regions) since it has a relatively strong Zeeman coefficient (0.77 Hz/microG). In the past it has been difficult to achieve the requisite signal-to-noise to convincingly detect the Zeeman effect in this molecule. The new K-band array would be an important step. -- CrystalBrogan - 19 Nov 2007

The balance between the continuum and line polarization needs should be decided based on whether the instrument really will have decent continuum capabilities to start with. -- CrystalBrogan - 19 Nov 2007