TRD straws status report from 14/03/ 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 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 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= Z=53.06Z= Z=25.212Z=1.698 Z= Z= Z= Z=

Z1= Z2= Z1= Z2= Z1= Z2= Z1= Z2= Towards acceptance definition: TOF (source: TofDBc)

Towards acceptance definition: TRD (source: AC::AMSGeometry) Z= 86.1Z=141.2 Layer 0Layer 20

Towards acceptance definition: ECAL (source: group A preselection) Z1= Z2 = (Exit_in_32_4 && Entry_in_32_4) && ( Exit_in_31_5 || Entry_in_31_5 )

Acceptance planes summary: We have to agree to use max span tracks to check acceptance criteria: – trk_track->iTrTrackPar(1,3,3); Here is a full list of Z which we have to store in particle and efficiency sample selection: Z [cm] detector TRK plane TRK plane TRD plane TRK plane TRD plane TRK plane UTOF layer TRK plane UTOF layer LTOF layer UTOF layer LTOF layer UTOF layer LTOF layer TRK plane LTOF layer TRK plane TRK plane TRK plane ECAL top face ECAL bottom face 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 m 2 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: 22 22

ToyMC for GF evaluation. AMS-02 acceptance planes Trk span Det. cross Inner (all inc.) Inner *L9 * !L1 Inner *L1 * !L9 Inner *L1 * L9 Inner *!L1 * !L9 Tof 4/4 * Trk Inner (all inc.) ± ± ± ± ± 1.0 TRD * !ECAL ± ± ± ± ± 0.8 ECAL * !TRD ± ± <0.001 TRD * ECAL ± ± ± ± ± 0.03 !TRD * !ECAL ± ± 0.04 < ± 0.4 Geometric factors for various detector sets and acceptance planes combinations (in cm 2 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

ToyMC checks: TOF 4/4 * TRD * ECAL * Trk Inner * !L9 * L1

ToyMC checks: TOF 4/4 * TRD * ECAL * Trk Inner * !L9 * !L1

ToyMC checks: TOF 4/4 * TRD * ECAL * Trk Inner * L9 * L1

ToyMC next step. Adding magnetic field