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

Fitted drift distance for straw 17, for all tracks, and tracks through all 3 straws in the same vertical column, hit threshold 5sigma (left) and 10sigma (right)

fitted drift distance for straw 17 (straw 17 is 20th in the root tree) for all tracks and same-column tracks, threshold 5sigma

fitted drift distance for straw 17 for all tracks and same-column tracks, threshold 10sigma

Same again with more bins

fitted drift distance for straw 17 (straw 17 is 20th in the root tree) for all tracks and same-column tracks, threshold 5sigma

fitted drift distance for straw 17 for all tracks and same-column tracks, threshold 10sigma