Geometry used in simulation/embedding for hits projection

For embedding with SSD, we project GEANT hits on real geometry.

But for plain simulation, the projection is done too but on the ideal geometry ; so that we don't expect any hits removal.

First step : check plain simulation.

A few hits cannot be a part of active wafer area ; this is the equivalent of the dead hits list from previous St_sls_Maker (prior embedding updates) .

The requirement is :

• |xL| < waferHalfActiveLength 
• |yL| < waferHalfActveWidth

where :

+--------------------+-------------------+

| waferHalfActLength       | waferHalfActWidth |

+--------------------+-------------------+

|       3.6500000000        |      2.0000000000 |

+--------------------+-------------------+

I ran over 1 event :

chain: 

trs,srs,fss,ssd,y2007,Idst,IAna,l0,tpcI,fcf,ftpc,Tree,SvtCL,svtDb,logger,ITTF,Sti,SsdIt,SvtIt,geant,evout,tags,bbcsim,tofsim,emcY2,EEfs,-GeantOut,big,-dstout,fzin,MiniMcMk,clearmem,VFMinuit,McAss,McAna,MiniMcMk

file : /star/rcf/simu/rcf1296_02_100evts.fzd

and get :

St_sls_Maker:DEBUG - Size of collection =1854

St_sls_Maker:INFO  - Num of SSD geant hits =1854####    ->  1845 HITS READ FROM TABLE        ####

St_sls_Maker:INFO  - ####    ->   2 DEAD ZONE HITS REMOVED      ####

results : 11 hits are removed.

Looking in details gives :

St_sls_Maker:DEBUG - Track projection on Global x =3.80523 y =22.3781 z =0.174416

St_sls_Maker:DEBUG - xg[0] = 3.80523--> to local --> xl[0] = -3.43259

St_sls_Maker:DEBUG - xg[1] = 22.3781--> to local --> xl[1] = -2.00058

St_sls_Maker:DEBUG - xg[2] = 0.174416--> to local --> xl[2] = 4.20291e-16

--> So this hit has a local Y position xL = -2.00058 and is removed because -2.00058 < -2.000

It just fall into the dead area

 

Geometry taken in :

1. plain simulation : here
2. real data : here (to run the real data, I took the chain and the file from $STAR/StRoot/macros/embedding/bfcMixer_TpcSsdSvt.C)
3. embedding : here

For example , i printed below the ssdWafersPositions (for some wafers) used in these 3 chains 

Plain Simulation :

 StSvtDbMaker:INFO  - *** StSvtDbMaker::Make() == StOK(0) ***

 i = 0 IdWafer = 7101

ii=0 drift=1 transverse=0 direction=-0 center=0

ii=1 drift=0 transverse=0 direction=1 center=23.177

ii=2 drift=0 transverse=1 direction=-0 center=-32.625

 i = 1 IdWafer = 7102

ii=0 drift=0.97705 transverse=0 direction=0.21303 center=7.159

ii=1 drift=-0.21303 transverse=0 direction=0.97705 center=21.647

ii=2 drift=0 transverse=1 direction=-0 center=-32.625

 i = 2 IdWafer = 7103

ii=0 drift=0.86949 transverse=0 direction=0.49394 center=13.475

ii=1 drift=-0.49394 transverse=0 direction=0.86949 center=18.144

ii=2 drift=0 transverse=1 direction=-0 center=-32.625

 i = 3 IdWafer = 7104

ii=0 drift=0.67688 transverse=0 direction=0.7361 center=18.376

ii=1 drift=-0.7361 transverse=0 direction=0.67688 center=13.156

ii=2 drift=0 transverse=1 direction=-0 center=-32.625

 i = 4 IdWafer = 7105

ii=0 drift=0.41945 transverse=0 direction=0.90778 center=21.518

ii=1 drift=-0.90778 transverse=0 direction=0.41945 center=6.9087

ii=2 drift=0 transverse=1 direction=-0 center=-32.625

 

Real Data :

i = 0 IdWafer = 7101

ii=0 drift=0.9999 transverse=0.001987 direction=0.014052 center=-0.056608

ii=1 drift=-0.014051 transverse=-0.00064504 direction=0.9999 center=23.288

ii=2 drift=-0.0019957 transverse=1 direction=0.00061706 center=-32.743

 i = 1 IdWafer = 7201

ii=0 drift=0.9999 transverse=0.0022319 direction=0.014052 center=-0.047591

ii=1 drift=-0.014051 transverse=-0.00064848 direction=0.9999 center=23.285

ii=2 drift=-0.0022407 transverse=1 direction=0.00061706 center=-28.392

 i = 2 IdWafer = 7301

ii=0 drift=0.9999 transverse=0.0022139 direction=0.014052 center=-0.039074

ii=1 drift=-0.014051 transverse=-0.00064823 direction=0.9999 center=23.282

ii=2 drift=-0.0022227 transverse=1 direction=0.00061706 center=-24.042

 i = 3 IdWafer = 7401

ii=0 drift=0.9999 transverse=0.002005 direction=0.014052 center=-0.030658

ii=1 drift=-0.014051 transverse=-0.00064529 direction=0.9999 center=23.28

ii=2 drift=-0.0020137 transverse=1 direction=0.00061706 center=-19.693

 i = 4 IdWafer = 7501

ii=0 drift=0.9999 transverse=0.0021269 direction=0.014052 center=-0.023141

ii=1 drift=-0.014051 transverse=-0.00064701 direction=0.9999 center=23.277

ii=2 drift=-0.0021357 transverse=1 direction=0.00061706 center=-15.343

Embedding :

StSvtDbMaker:INFO  - *** StSvtDbMaker::Make() == StOK(0) ***

 i = 0 IdWafer = 7101

ii=0 drift=0.999899 transverse=0.00198696 direction=0.014052 center=-0.0566085

ii=1 drift=-0.0140508 transverse=-0.00064504 direction=0.999901 center=23.288

ii=2 drift=-0.00199572 transverse=0.999998 direction=0.000617057 center=-32.7428

 i = 1 IdWafer = 7201

ii=0 drift=0.999899 transverse=0.00223193 direction=0.014052 center=-0.0475909

ii=1 drift=-0.0140506 transverse=-0.000648483 direction=0.999901 center=23.2852

ii=2 drift=-0.00224071 transverse=0.999997 direction=0.000617057 center=-28.3925

 i = 2 IdWafer = 7301

ii=0 drift=0.999899 transverse=0.00221394 direction=0.014052 center=-0.0390738

ii=1 drift=-0.0140506 transverse=-0.00064823 direction=0.999901 center=23.2824

ii=2 drift=-0.00222271 transverse=0.999997 direction=0.000617057 center=-24.0425

 i = 3 IdWafer = 7401

ii=0 drift=0.999899 transverse=0.00200495 direction=0.014052 center=-0.030658

ii=1 drift=-0.0140508 transverse=-0.000645293 direction=0.999901 center=23.2796

ii=2 drift=-0.00201372 transverse=0.999998 direction=0.000617057 center=-19.6932

 i = 4 IdWafer = 7501

ii=0 drift=0.999899 transverse=0.00212694 direction=0.014052 center=-0.0231409

ii=1 drift=-0.0140507 transverse=-0.000647008 direction=0.999901 center=23.2768

ii=2 drift=-0.00213571 transverse=0.999998 direction=0.000617057 center=-15.3432

 

Results :

• in simulation, we can see that ideal geometry is taken 
• in real data and embedding, real geomtry is taken.

the only difference is in the digits number : for example wafer 7101 center[2] =-0.056608 for real and center[2] = -0.0566085 for embedding.

The last digit is approximated to the previous