The use of Cerenkov detectors for particle identification is a well established technique in nuclear and particle physics. They are nearly ubiquitous as part of detector packages in magnetic spectrometers and together with shower counters, Cerenkov detectors serve to identify the charged particles passing through the momentum acceptance of the spectrometer. As part of the 12 GeV upgrade at Jefferson a new spectrometer, the Super High Momentum Spectrometer (SHMS) will be built in Hall C.
Analyzing momenta up to 11 GeV/c at scattering angles from 5.5 to 40.0 degrees, the SHMS will reach kinematic regions in which the pion background rate dominates the scattered electron rate by more than 1000:1. The suppression of these anticipated pion backgrounds while maintaining efficient identification of electrons is therefore one of the main duties of the SHMS detector elements and the SHMS Noble Gas Cerenkov Detector shoulders a large portion of this particle identification burden. Here I report the preliminary design choices for a noble gas threshold Cerenkov detector that will meet these twin goals of suppression and identification.