How to trigger to test MDT with cosmic rays?

1. How to trigger to test MDT with cosmic rays? authors

5. Trigger rate (f ) limited by the DAQ system to about 300 Hz • Time encoding programmable window (T ) varied between 2 s and 35 s • Cosmic rays rate (r ): • If rT <<1 and 700 ns << T << 1/f • Number of events in a time interval t with a two multilayer track: • N=rTf t =300 s-1 · T(s)·10-6 s · 300 s-1 · t(h) · 3600 h = 324 T(s) t(h) ev/h

6. Test in the lab. • Trigger: • Cosmic trigger. RPC hodoscope (t0’s and trigger time available) • Random (time unit pulser) • 2 BIL chambers (144+144 tubes) • Standard threshold. (Noise level? plot) • Data collection: cut on word count corresponding to 2 hits in the event. • Analysis: • Standard reconstruction for cosmics using all available information from the trigger • Track reconstruction for random trigger samples: event by event fit of t0 • Track reconstruction of cosmic samples with t0 fit (for comparison)

7. Hit multiplicity Recorded events (at least 2 hit in the event required) Number of hits in ML1 vs Number of hits in ML2 in one chamber Random trigger Encoding window = 2.2 s

8. Tracking Alghoritm Tube track (pattern recognition): find at least 6 tubes aligned on a possible straight track. • Track fit and t0 determination: • Correct all the drift times with respect to the smallest • tidrift= tidrift - tmindrift • 2) Iterative search of the best time to add to the measurements to minimize chi2 • Calibration of the rt relation required but... (forthcoming slides)

9. Spettro tdc standard su autotrigger Panettone standard su autotrigger

10. autotrig autocal

11. autotrig autocal

12. Comparison trigger- no trigger Check (cosmic trigger file) drift time diff theta diff

13. Plot chi2, pchi2

14. Random trigger Changing time encoding window

15. Panettone autotrigger (diverso da quello con trigger rpc?) Panettone con hit on pattern vs panettone con hit on track

17. rATLAS << r Rome Reduction factor 30 fATLAS >> f RomeRome daq rate 300 Hz