Pixel Offline Status Jianchun Wang Syracuse University 09/17/04, Pixel testbeam meeting.
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Pixel Offline Status Jianchun Wang Syracuse University 09/17/04, Pixel testbeam meeting
2 Detector Configuration YXX 1 Beam 2345678910111213 XXYXX Plane Orientation 12346758iz X reference planes Y reference planes
3 X Reference Issue We use planes 4 and 10 (both at ~10°) as X reference planes. The tilted angles are not precisely known. The effect of unknown angle: Perpendicular X reference planes would be better. We could however use precisely measured X information at planes 3 and 11 (Y planes) to determine the angles of planes 4 and 10. We need events with 2-column hits on both planes 3 and 11. Statistic error is a big issue. About 180 runs are added together. In total we have about 200 tracks with plane 3, 11 + 4/10. It is very marginal and it is the best we can have for now. The tilted angles are determined to be 164 and 172 mrad instead of previously assigned 175 mrad, not as bad as I was initially afraid. The effect is about 10 m.
4 Alignment Status We have 5 sets of runs, each divided into several groups. Within a group we believe that the geometry configuration is the same. I had finished alignment on the first two sets and in the middle of the 3 rd one. The ntuples of the first two are generated except for two. The aligned angle for DUT (plane 7). Nominal AngleAlignment mrad (run) degreemradSet 1Set 2 0079.6 (1732)0.5 (1928) 587.3112.2 (1757)91.7 (1932) 10174.5168.4 (1763)179.1 (1914) 15261.8260.5 (1769)258.8 (1946) 20349.1349.1 (1834)345.4 (1951) 25436.3432.8 (1839)433.5 (1906)
5 Couple of New Features There is a user_trigger in the offline just after read in and decode the event. Currently the trigger requires that at least 5 out of 6 non-DUT planes have hits. I added an option “filter” in the tb_control. It starts writing out the events that passes the trigger or more sophisticated selection. This could significantly reduce the size of data while keep all interesting events. The program now can have multiple input files (Caution: the input file name is a variable array instead of just a variable). This is true for both normal analysis and alignment.
6 The Issue of 2 Charles reported seeing abnormal 2 values, more than a factor of 2 larger than anticipated. I checked through the whole chain of code till deep into Kalman filter and found nothing extraordinary. The 2 value can be affected by both the resolution assigned to the measurement and the alignment. I think it is the second in his case. I run 20K events in run 1977 to verify the 2 is OK. 22 Prob( 2, ndof) Due to under- estimated error
7 Variables in CWN Track Block ievt, ntrks, n_klm_ok, itrk, klm_ok, x_int, x_slp, y_int, y_slp, chisq, cl, ndof, fixyslp, yclass, nplanes Plane Block (ngeom elements except for ngeom) ngeom, itype, iort_row, nclus, iclus, npix, nrow, ncol, rowb, colb, rowq, colq, eta, sumq, xg, yg, xl, yl, xsig, ysig, xw, yw, zw, rxi, srxi, spxi, ryi, sryi, spyi, rxo, srxo, spxo, ryo, sryo, spyo, xf, yf, rhof, xslp, yslp, infitx, infity Hit Block (nhit elements except for nhit) nhit, ipln, icol, irow, iadc, icls, qval I will update instruction to include explanations. Currently please see file /prj/btev/pixel_tb04/testbeam/monitor/src/fill_ntuple.F or see Charles web page. From an old talk
8 Histogram ID 11100 Geometry parameters 11200 Geometry parameters after alignment 11300 Global parameters and detector parameters 11400 Simulation parameter maps 11500 Charge simulation parameters 21000 Simulated tracks 22000 Simulated hits 31000 Track summary 32000 MINUIT fit 41000 Hit information 42000 Cluster information 43000 Difference of reconstructed hit position and generated position 51000 Form track 61000 Kalman filter The easiest way to check the histogram is to use manip.kumac macro file in PAW
9 To Do List 1)Finish alignment and ntuple generating. 2)Skim all data files with hit trigger. 3)Include real ADC-charge conversion once Lorenzo finishes the calibration. Currently the conversion uses a set of value I chose long time ago. And we have only charge weight, no eta correction. 4)Put more realistic expected resolution. Currently we use our knowledge from last test beam. 5)We need chi2 value without DUT hits for track selection. If you choose very loose chi2 for now it is not a big issue. 6)Update offline instruction.