The evolution of magnetized neutron stars with field strengths of approx. 10/sup 12/ gauss that are accreting mass onto kilometer-sized polar regions at a rate of approx. /sup 13/ M/sub 0/yr/sup -1/ is examined. Based on the results of one-dimensional calculations, one finds that stable hydrogen burning, mediated by the hot CNO-cycle, will lead to a critical helium mass in the range 10/sup 20/ to 10/sup 22/ g km/sup -2/. Owing to the extreme degeneracy of the electron gas providing pressure support, helium burning occurs as a violent thermonuclear runaway which may propagate either as a convective deflagration (Type I burst) or as a detonation wave (Type II burst). Complete combustion of helium into /sup 56/Ni releases from 10/sup 38/ to 10/sup 40/ erg km/sup -2/ and pushes hot plasma with ..beta.. > 1 above the surface of the neutron star. Rapid expansion of the plasma channels a substantial fraction of the explosion energy into magnetic field stress. Spectral properties are expected to be complex with emission from both thermal and non-thermal processes. The hard ..gamma..-outburst of several seconds softens as the event proceeds and is followed by a period, typically of several minutes duration, of softer x-ray emission as …

During this period new modules and devices will be built to be used in Experiment 749 at the A.G.S. Included will be approx. 200 channels of A-D converters for Pb-Glass Cerenkov counters, 2000 channels of proportional wire chamber readout, cable segments, segment interconnects, a new unibus interface, and a new on-segment processor. These items and perhaps others will be ready by the end of 1981.