A Time-of-flight system for BNL-AGS Experiment 896

K. Kainz and W. J. Llope

This page was last updated on October 23, 1998.

• Graph 1 introduces the E896 detector geometry (incl. TOF), and summarizes the uses of the TOF detector in E896.
• Graph 2 shows a picture of the full TOF detector, describes the 3 component arrays, and denotes which daughters each wall is capable of accepting.
• Graph 3 discusses how TOF detector information will be used to identify particles in the DDC.
• Graph 4 summarizes TOF electronics, lists the AGS runs in which TOF participated, and demonstrates the liveness of the array throughout these runs.
• Graph 5 summarizes the three calibration-related analyses (pedestal correction, slew correction, ADC-to-charge scaling) which are complete at this time.
• Graph 6 briefly discusses the use of TOF as a neutral-vertex trigger during p98.
• Graph 7 is a quick summary of the present and future TOF analysis plans.

Tentative transparencies

Graph 8 shows the hole-hit distribution for extrapolated DDC tracks (left frame) and the momentum distribution of extrapolated tracks upon each slat. These are the plots discussed during the 10/23/1998 telephone conference.

From the left frame, it appears that extrapolatable DDC tracks account for roughly 10 percent of all TOF slat hits, largely independent of slat location.

The right frame shows that, in the area of TOF just to beam-left of the gap for Au beam, the average momentum is not too far away from the beam momentum of ~11.3 GeV/c.

Could the rather high momenta seen further to the left of the gap possibly be due to light fragments (alphas, etc.)?

We are currently trying to collect a greater number of hits for each slat, to see if a dependence of TDC upon track momentum is present. If this correlation does appear, we should like to incorporate that result into this transparency, and perhaps show it (in place of Graph 6) at the DNP Meeting.