CDC prototype drift times

CDC prototype cosmics data

• 50/50 mixed Ar, CO₂
• Recalibrated MFCs
• Outer plenum added to CDC prototype to prevent leaks
• New pre-production HVB
• 2100V
• Modified preamp4 (terminating resistors removed)
• Prototype tilted at 30^o to enclosing scintillators (scints trigger the daq)
• New timing setup (recording coinc logic signal)

Purple histogram is drift time in tracks through each straw; gray selects tracks through all 3 straws in same column, hit threshold is 5sigma over pedestal

drift times for all tracks and tracks in single column of straws, threshold 5 sigma

hit threshold is 10sigma over pedestal

drift times for all tracks and tracks in single column of straws, threshold 10 sigma

Below: Purple:all tracks through straw, grey: track angle 5° or more to vertical, light blue: track angle less than 5° to vertical. Hit threshold 5 sigma over pedestal

drift times for all tracks, tracks angled at 5° or more to vertical and at less than 5° to vertical, threshold 5 sigma

Same again just for straw 17

single column of straws, threshold 5 sigma

single column of straws, threshold 10 sigma

track angles, threshold 5 sigma