Hall A

Hall A currently houses two high resolution spectrometers. One is used as an electon arm, the other a proton arm. A majority of the experiments run in Hall A are (e,e'p) coincidence. Three FASTBUS crates and 1 VME crate interface the spectrometer detectors and beam line. Typical running conditions do not exceed 2 $\,$kHz with 20% deadtimes. Readout latency for the complete system is about 300 $\mu$s, but front-end module conversion times are only on the order of 50 $\mu$s or less. However, because the front-end hardware in the VME crate is not buffered, its event by event readout drives the deadtime (which otherwise could a factor of two lower).

Proposals for the energy upgrade in Hall A include a possible third arm spectrometer with associated front-end crates. DAQ throughput and deadtime could be improved with the introduction of a pipelined ADC and high-resolution TDC.