Proton-proton elastic scattering using 201-and 400-GeV/c extracted beams at Fermilab has been measured in the region 4.9

Proton-proton elastic scattering has been measured in the region 4.9< \t I < 12.1 GeV 2 at a beam momentum of 201 GeV/c. If the form exp(A£) is fitted to the data, the exponent A gradually changes from 1.5 to 0.9 GeV" 2 over our t range. The data are consistent with the form exp(-6.6^±). A comparison with intersecting storage ring results shows that in this kinematical region the slopes are about the same, but dcr/dt at fixed t is still dropping with energy.

Proton-proton elastic scattering at 400 GeV/c has been measured in the region 5.4 < -t < 14,4 QeV 2 with no sign of a second dip or "break." If the data are fitted by exp(At), the slope A decreases from 1.5± 0.1 to 0.7± 0.2 GeV" 2 over the range. At fixed t the 400-GeV/c cross sections are about 0.6 times those at 200 GeV/c in this t range. At fixed 0_ m =15°, da/dt^s""where n= 9.7±0.3.

An inexpensive microcomputer-based system has been developed for fast digital synthesis of complex sound stimuli, recording of neural activity, and interactive on-line histogramming and plotting of response properties. The hardware requirements for stand-alone synthesis and spike recording capability are an Apple Macintosh II, a GW Instruments data acquisition card, and a modest amount of interfacing and signal conditioning electronics. Off-line analysis of acquired data files can be performed on any current Macintosh. Stimuli can be computed synthetic sounds or digitized natural sounds; both types are presented at sampling rates of up to 100k samples/s with concurrent timing of spikes at 10-μs resolution. The system is especially suited for experiments in which sounds must be rapidly resynthesized as a stimulus parameter is changed under manual or automatic control. A modular software design allows installation of new synthesis and analysis routines, or new drivers for alternate hardware interfaces. Synthesis parameters and raw spiketime data are saved to disk files in a format that allows exact recreation of stimuli and precise correlation of spikes with temporal features in those stimuli. [Work supported by NINCDS.]