Scanning Tips and Tricks
Jump to navigation
Jump to search
Scanforth
- follow the tracks from the primary vertex
- at all stopping points, open a volume
- volume: 3 up, 5 down, 7x7 mm2 (max 7x7 mm2 at the 5th plate down)
About Brick Number
Example you have to scan brick 36423
in the scanning scripts put 36423 but in Sysal (ChangerStatus.txt file) the brick number MUST be ONLY the 4 last number : 6423
Create Prediction (for the ScanForth for ex)
manually create prediction for the scan forth: Create Scanforth Prediction
or here:
{ #include "scan.C" EdbScanProc sproc; sproc.eProcDirClient="/terabig/scan/MICROSCOPE3/ONLINE"; // work directory EdbPattern pred; // track stopped at pl24 pred->AddSegment(1,44480.9,16508.4,-0.123,0.04,32); // last BT from the track in linked_tracks.root (-> affine transformation applied!) EdbAffine2D *aff = new EdbAffine2D(0.998787,-0.003071,0.000637,0.995767,326.291107,-348.701843); // AFF from Pl24 int id[4]={36423,24,1,300}; aff->Invert(); // to "unapply" AFF transformation pred.Transform(aff); // to "unapply" AFF transformation pred.Print(); OverwriteErrors(pred,50.,50.,0.,0.6,0.6); sproc.WritePred(pred,id); }
Screen Function
All the scanning processes should be started in a screen function in order to be able to access from everywhere. In addition, it's very easy to kill an process when it hangs (just kill the screen).
- screen -S myscreen : create a new screen - screen -r : reattach to the screen - screen -x : additionally attach to the screen - inside the screen in order to deattach: Ctrl A D - inside the screen to close: exit
Avoid Odyssey Crashes
Start process with a remote desktop and when it's running, close the remote desktop.
rdesktop -g 1272x930 -k de-ch -u scanner lheppc9
Scanning efficiency issues
Dear Francesco, this happens when you hit the tracking timeout. In this case, ZERO tracks are generated. Try increasing the timeout in SmartTracker8.xxx Cheers Cristiano ----- Original Message ----- From: "Francesco Di Capua" <fdicapua@mail.cern.ch> To: <opera-scanonline@cern.ch> Sent: Friday, July 18, 2008 10:38 AM Subject: sysal with high fog > > Dear All, > we received a brick (n.117472) related to the CC event 22877818 with very > high level of fog, > we located and reconstructed vertex in intercalibration areas (see > picture), > in order to have a reasonable scanning speed the intercalibration areas > was done with high treshold (900,840) and slope tolerance to 0.4 rad. > Quality of data is not very good, low efficiency and a lot of views with > few tracks found (see surface plot). > Trying to do a better quality volume for vertex analysis, we tried to > decrease tresholds and increase slope tolerance to 0.6, but we found a > strange behaviour of Sysal, the scanning seem to start but not microtracks > at all are found during data taking. > Do you have any suggestion for parameters to be used in this difficult > conditions? > > Thanks > Francesco > >
Track momentum calculation
Letter from Frederic: Dear all, I add a new function in check_vertex_totalscan.C which allows to estiomate the momentum of a track (using MCS from Magali study). You just have to call the function PMCS with the trackID as argument. Exemple below: void PMCS(int IDTR) { //EdbTrackFitter tf; // create track fitter object EdbMomentumEstimator tf; tf.SetParPMS_Mag(); //set parameters for detheta=f(theta) (angular dependance of BT resolution) tf.eDT0=0.002; //Change a parameter for(int i=0; i<gAli->Ntracks(); i++ ){ EdbTrackP *t = gAli->GetTrack(i); float p = tf.PMS_Mag(*t); float pmin=tf.ePmin; // 90% CL minimum momentum float pmax=tf.ePmax; // 90% CL maximum momentum if (IDTR == t->ID())cout << p << " - " << fabs(p-pmin) << " + " << fabs(p-pmax) <<endl; } }
Track momentum calculation for scanback or scanforth track
A new script /terabig/scan/macros/testP.C do the momentum calculation of a track using data from scanback or scanforth. It works in the same way as explain above. (see comments inside the scripts for details).
Vertex between 2 BT (or tracks)
A new script /terabig/scan/macros/vertex_BT.C allows to calculate the vertex position between 2 BT. It returns the vertex position and the IP (the closest distance between the 2 BT). In the same script you have another possibilty to estimate the vertex position between a known BT ( that you have to specify) and all the BT from a cp file (that you have to specify).
IP between a vertex and a BT (or track)
The script /terabig/scan/macros/vertex.C allows to check if a BT from a cp file can be attached to a known vertex that you have to specify. The output is the IP of the BT w.r.t to the vertex.
Change placement of emulsion on stage
to do this, you have to change two settings in the opposit way
- in PlateChanger, change in Stage Homing the Stage limiter offset on X and Y
- in Machine default of the Stage, change the XYreference (in opposit way)