A SEARCH FOR SMALL-SCALE ANISOTROPY IN THE COSMIC MICROWAVE BACKGROUND

We report the preliminary result of a search for cosmic microwave back ground (CMB) anisotropy. We made observations using a specially design ed radiometer and on-axis Cassegrain telescope. The beam size was 12' at a frequency of 90 GHz. Observations were made during 1993 January f rom the South Pole. We observed five regions of sky rear declination - 75-degrees, and set a 95% confidence level upper limit of DELTAT < 2.3 x 10(-5)T(CMB) on Gaussian-correlated CMB anisotropy at an angular sc ale of 0.15-degrees. This is the lowest upper limit to date on CMB ani sotropy at this angular scale.