High luminosity will be necessary for the study of many of the new phenomena expected in the SSC energy region. Particle detectors, however, are limited in the number of simultaneous interactions which they can handle, and thus need a good duty cycle with collisions spread out in time to the greatest extent possible. To avoid the larger number of stored protons required for continuous beams, we have considered bunched beams of protons crossing at a small angle. Plots are given of the dependence on bunch separation of the emittance, number of protons, etc., needed for 10/sup 33/ cm/sup -2/ sec/sup -1/. In order to minimize the number of stored protons (approx. 10/sup 14//ring), an emittance roughly ten times smaller than that presently achieved at high energies is required for a bunch separation of 6 meters (20 nsec).

Hugoniot data for water ice are available for pressures ranging from about 150 MPa to about 50 GPa from initial states near 260 K. Limited data on porous ice (snow) at the same initial temperatures are available from 3.5 to 38 GPa and initial densities of 600 and 350 Mg/m/sup 3/. Above about 5 GPa, the data are fairly well-fit by a linear relation between shock and particle velocity: D(km/s) = 1.79 + 1.42u. However, a quadratic form fits the data better: D(km/s) = 1.32 + 1.68u - 0.035u/sup 2/. At lower stresses the velocity is a very complicated function of particle velocity due to elastic propagation, yielding and several possible phase changes. The Hugoniot elastic limit (HEL) of ice at these temperatures is about 180 +- 20 MPa with the elastic waves travelling at about 3900 m/s. The mean stress at the HEL is 115 +- 14 MPa. Comparison with strength measurements at lower strain rate indicates that failure at the HEL probably involves fracture and is almost independent of both temperature and strain rate. Ice V has been reported at about 600 MPa, and ice VI at 1.9 GPa and possibly at 3.7 GPa. Transition to ice III …