The
second phase of the Medium-Scale Anisotropy Measurement
(MSAM2) uses an adiabatic demagnetization refrigerator
to cool a new radiometer to 0.1 K. This new instrument,
equipped with 5 spectral bands between 2.3 and 5.67 icm
(70 and 170 GHz, 1.76 and 4.3 mm), will provide a powerful
observational check for foreground sources as well as
provide at least a factor of 3 improvement over MSAM1
sensitivity to CMBR anisotropy. The increased sensitivity
and smaller beam size (20' FWHM) will allow us to constrain
cosmological models and parameters by measuring the CMBR
correlation function out to the 2nd acoustic (Doppler)
peak - the predicted characteristics of this peak are
highly model dependent.