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TRD straws status report from 14/03/2012 + AMS-02 acceptance for lepton flux. N. Nikonov. TRD occupancy monitoring for last week. Straw inefficiency example for aligned TRD (pass4 stream). TRD straws inefficiency vs. time. TRD gas refill 21-22 Dec 2011.
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TRD straws status reportfrom 14/03/2012+AMS-02 acceptance for lepton flux N. Nikonov
TRD straws inefficiency vs. time TRD gas refill 21-22 Dec 2011
Conclusions and “To do” list for TRD occupancy monitor • General work is already finished • Automatic every week processing requires machine which can submit jobs use crontab. • Evaluation can be done on daily basis, however, for statistical reason it’s better to have not less than 4 days. • The method works now on 1 week basis, which supposed to be enough. • Time – dependence of straw inefficiency was done for first half year of data taking use B620 pass4 stream. • To be continued till March 2013. • 2013 studies can be done on std stream as well as weekly reports since method is robust and can find bad straws even if TRD is not aligned.
AMS-02 acceptance check and studies for lepton analysis • From MC we measure: • GF of sensitive trigger volumes X Trigger efficiency X TrTrack efficiency. • From ISS data we can estimate: • Trigger efficiency for selected particle sample use Tof ¾ unbiased trigger • TrTrack efficiency use other detectors: ECAL for energy measurement, ToF, TRD to check if particle passed trough the tracker. • A question: How we can rely on MC? • The answer is: Let’s factorize problem • We can define “acceptance planes”: TrTrack – 9 planes, Tof – 4(2) planes, TRD – 2 planes, Ecal – 2 planes and store in preselection (x,y) of MaxSpan Track. • Make simple ToyMC, where only magnetic field involved and evaluate pure GF of this set of planes. • Since G4 doesn’t change particle ID due to Bremsstrahlung, ionization etc. , one can calculate: • GF pure on toymc X Trigg efficiency (ISS) X Trk efficiency (ISS) • This value should be the same what we have from MC. • The difference will give us understanding of systematic
Towards acceptance definition: TRK(source: TkDBc) Z=158.92 Z=53.06 Z=29.228 Z=-2.318 Z=25.212 Z=1.698 Z=-25.212 Z=-29.228 Z=-135.882
Towards acceptance definition: TOF(source: TofDBc) Z1=64.425 Z2=65.975 Z1=61.325 Z2=62.875 Z1=-64.425 Z2=-65.975 Z1=-62.875 Z2=-61.325
Towards acceptance definition: TRD(source: AC::AMSGeometry) Layer 0 Layer 20 Z= 86.1 Z=141.2
Towards acceptance definition: ECAL(source: group A preselection) Z1= -142.792 Z2 =-158.457 (Exit_in_32_4 && Entry_in_32_4) && ( Exit_in_31_5 || Entry_in_31_5 )
Acceptance planes summary: • Here is a full list of Z which we have to store in particle and efficiency sample selection: • We have to agree to use max span tracks to check acceptance criteria: • trk_track->iTrTrackPar(1,3,3); 21 pair of (x,y) at given Z has to be stored
How detector’s dimensions matches preselected data? Gaps here are due to ECAL geometry cuts in preselection • Inefficiency due to dead ladders. Should we cut these events? • Probably not because: • Flux isotropy, we calculate average efficiency • We enlarge border length, possible border issues • We wish to keep more statistics • Probably yes: • Quality of the fit will be better if we have more points
ToyMC for GF evaluation. Generation surface Generation surface: cylinder, R=110 cm, z[53.06, 170], GF = 37.3 m2 sr
ToyMC for GF evaluation. Simple tests • Measurement of GF for plane with known area • Measurement of GF for telescope with 2 circular and rectangular shapes: b2 a2
ToyMC for GF evaluation. AMS-02 acceptance planes Geometric factors for various detector sets and acceptance planes combinations (in cm2 sr)
ToyMC checks: TOF 4/4 * TRD * ECAL * Trk Inner (all) • This picture should corresponds to our preselection, • some differences due to: • finite rigidity of ISS particles (smoother edges) • not isotropic yet (no cutoff requirement) • toy mc has no “dead” TRK ladders