Tracker Status Outline Problem with tying tracker tracks

Tracker Status: Outline Problem with tying tracker tracks into global co-ordinates. Solved Part of the solution lead to a validation of the tracker software Digits Clusters Spacepoints Straight tracks Need to be Ready for February/March run Helical tracks Exposed a problem with the Simulation and Reconstruction Geometry Plots are for 7417 (except for helical tracks 7469) MICE VC 4 February 2016 Tracker Report Paul Kyberd

Digits i Upstream MICE VC 4 February 2016 Tracker Report Paul Kyberd

Digits ii Downstream – not set up properly. However even here if we cut on the number of hits in the plane – we get good results. One and only one hits on each plane Station distribution looks good MICE VC 4 February 2016 Tracker Report Paul Kyberd

Clusters i MICE VC 4 February 2016 Tracker Report Paul Kyberd

Clusters ii ✔ Ratio of 1 digit to 2 digit clusters exactly as expected from geometry MICE VC 4 February 2016 Tracker Report Paul Kyberd

Space-points Mean around 13 pe per cluster 2 pe cut can be raised to clean up Spacepoints used in tracks. Noise has gone. Peak the same Most upstream station MICE VC 4 February 2016 Tracker Report Paul Kyberd

Kuno plot Looks good Required peaks (dead/noisy channels which are not handled cause secondary peaks) MICE VC 4 February 2016 Tracker Report Paul Kyberd

Space point triplets and doublets US Good distribution and bad channels not hurting overall pattern MICE VC 4 February 2016 Tracker Report Paul Kyberd

Space point triplets and doublets DS Good distribution and bad channels not hurting overall pattern – even with poorly set up tracker MICE VC 4 February 2016 Tracker Report Paul Kyberd

Space point triplets and doublets DS beam profile looks good. MICE VC 4 February 2016 Tracker Report Paul Kyberd

Straight tracks Upstream x residuals Comparison with projected hit position from joining a hit in TOF 1 and TOF 2 Downstream y residuals Track finding efficiency US 99% DS … lower but H/W not S/W MICE VC 4 February 2016 Tracker Report Paul Kyberd

Straight tracks i Upstream x-y residuals Downstream x-y residuals Beam getting bigger as it moves along the channel. Good reconstruction of even in the presence of large amounts of noise. MICE VC 4 February 2016 Tracker Report Paul Kyberd

Helical tracks i Cuts: Hits in TOF 1 – one hit in every tracker plane Efficiency: Good efficiency to find tracks. Quality: Not possible to do as for the straight tracks – projected points Take found points and look in the x-y plane: trajectory a circle join points find perpendicular bisector of pairs. Gives independent estimate of centre MICE VC 4 February 2016 Tracker Report Paul Kyberd

Helical tracks ii Can be checked by hand looks reasonable and values good. For the full sample histogram sum of distances from the intersection points and the claimed centre – effective an un-normalised chi squared MICE VC 4 February 2016 Tracker Report Paul Kyberd

Helical tracks iii Looking in detail shows some tracks where one point is clearly wrong. Identify by looking for intersection points outside the rectangle formed by the points. Indicates something like 15% - (this cut will pick up some good tracks and miss some bad – not a precise estimate). MICE VC 4 February 2016 Tracker Report Paul Kyberd

Helical tracks iv The quality of the helices found are defined by a chi squared for the circle in the transverse plane and a line along the beam. Cut on the chi squared of the track to improve the sample Problem with the chi squared for the circle. Helical track fits works – but needs some more work MICE VC 4 February 2016 Tracker Report Paul Kyberd

Simulation and Reconstruction i Solving the problem of embedding the tracker local system into the global system revealed an inconsistency in the geometry description for simulation and reconstruction. Good news: the source data for both geometries is the same. Problem: the geometric description required for simulation is much more complex than that required for reconstruction. So the file is different Simulation requires the position “dead” material and a physical description of sensitive material … radiation length etc. Reconstruction only requires the position of the sensitive material. Switching to a uniform description is not practical GEANT expects a different description to MAUS

Simulation and Reconstruction ii Monte Carlo events reconstructed in the tracker Residual drifting MICE VC 4 February 2016 Tracker Report Paul Kyberd

Simulation and Reconstruction iii Source of errors: Differences in the way GEANT 4 handles information. Star: GEANT expects all dimensions as half lengths. Half lengths ended up in the reconstruction geometry Sliding: GEANT uses a left handed system Finally sorted at 3 am this morning Correct version will be in the next version of MAUS. Will look at way of automatically comparing the two files. MICE VC 4 February 2016 Tracker Report Paul Kyberd

Tracker Status: Conclusion Problem with tying tracker tracks into global co-ordinates. Solved Part of the solution lead to a validation of the tracker software Digits Clusters Spacepoints Straight tracks validated Ready for February/March run Helical tracks ✔� partial validation Tuning of cuts required Exposed a problem with the Simulation and Reconstruction Geometry Identified & corrected Available in MAUS 1. 5 MICE VC 4 February 2016 Tracker Report Paul Kyberd