A program is described for development of an automated supernova search based upon complete remote computer control of a telescope and vidicon digital imaging system. (GHT)

The results of fully dynamic computer simulations of collision cascades show an abrupt decrease in defect production efficiency beginning at energies about 10 times the minimum threshold energy in agreement with experimental results on resistivity damage rates at 4.2 K. A detailed analysis of the time development of a typical cascade reveals that this drop in efficiency is primarily due to recombination by defect transport during the cascade cooling phase. This transport is an order of magnitude larger than that predicted from equilibrium transport theory.

A computer model of a piezoresistive gauge subject to shock loading is developed. The time-dependent two-dimensional response of the gauge is calculated. The stress and strain components of the gauge are determined assuming elastic-plastic material properties. The model is compared with experiment for four cases. An ytterbium foil gauge in a PPMA medum subjected to a 0.5 Gp plane shock wave, where the gauge is presented to the shock with its flat surface both parallel and perpendicular to the front. A similar comparison is made for a manganin foil subjected to a 2.7 Gp shock. The signals are compared also with a calibration equation derived with the gauge and medium properties accounted for but with the assumption that the gauge is in stress equilibrium with the shocked medium.

Some data sets dealing with the hazards of low-level radiation are discussed. It is concluded that none of these reports, individually or collectively, changes appreciably or even significantly the evaluations of possible low-level radiation effects that have been made by several authoritative national and international groups. (ACR)

Two NbTi and two Cu wires were irradiated with 14.8 MeV neutrons at 4.2 K to fluences of 6 to 8 x 10/sup 20/ n/m/sup 2/, using RTNS-II. Electrical resistances of Cu were monitored during irradiation. Magnetoresistances were measured in fields up to 12.4 T before and after irradiation and after isochronal annealing up to 273 K. Critical currents of NbTi were measured after irradiation, in feilds up to 10 T. The initial rate of increase of resistivity of the Cu was found to be 2.23 x 10/sup -31/ (..cap omega..-m)/(n/m/sup 2/). This rate could be predicted from fission reactor irradiations using damage energy scaling. The maximum observed change in the NbTi critical was a decrease of 3% at 4 T. At 6, 8, and 10 T there were no significant changes.

Calculations suggest that experiments relating to beam deposition, focusing and transport can be performed within the context of current test-bed accelerator design proposals. Since the test beds have lower ion kinetic energy and beam pulse power as compared to reactor drivers, we achieve high-beam intensities at the focal spot by using short focal distance and properly designed beam optics. In this regard, the extremely low beam emittance of suggested multi-beam designs are very useful. Preliminary results suggest that intensities of greater than 100 TW/cm/sup 2/ are achievable. Given these intensities, deposition experiments with heating of disks to greater than 100 eV are expected. We could also expect as much as 1 to 3 kA of incident ion current on these disks with beam intensities almost comparable to that of reactor targets. Thus, if any anomalous plasma effects on deposition emerge, the conditions should be available for testing some of them. On the other hand, these deposition experiments have low ion kinetic energy per nucleon. About 4 to 5 MeV/nucleon is achievable if lighter ions such as sodium were used. But for lighter ions, plasma effects in deposition might be more severe because heavy-ion beams are more stiff.