Visual check of CMS tracker geometry
This is a visual check of CMS tracker geometry description in Orca.
This is done with maps like the one in the figure above.This is a 2D map
with each one of the around 17000 modules drawn in a position similar
to what you would get by laying them on the floor in places similar to their
The real position in space of the modules in the 41 layers that form the tracker is shown in this
This was done in April 2002 and is used as a reference to show what changes
we had since this date.
DetUnitId for each module. Update of the previous image. The image must be looked from firefox with svg enabled. The Strip Detector has a new numbering scheme completely different from previous version.
The first fed trackermap for
a TIF tracker layout. In the layer position the fed assembly that feeds the
layer modules is drawn. When you pass the mouse on a fed you get the fed code
and the module id.
DetUnitId for each module. Update of the previous image. The image must be looked from firefox with svg enabled. Some changes in TEC
petal 1 backward produce "strange" module numbering in the ring.
DetUnitId for each module(embedded,batik). Update of the previous image. Bug concerning the stereo pairs corrected (the stereo module was called non stereo and viceversa) .
DetUnitId for each module(embedded,batik). Update of the previous image. Bug in TEC 7 and 8 corrected. The third piexel endcap layer has disappeared.Problems with endcap pixel numbering?
DetUnitId for each module(embedded,batik). Update of the previous image. TEC 7 and 8 show still some problems in petal numbering. Problems with endcap pixel numbering?
New Tracker Geometry implemented in the new Framework(last update CMSSW_0_4_0)
DetUnitId for each module(batik). SVG image:requires the Adobe plugin or the batik browser(png version here). TEC petals, PIXB ladders, TIB strings and TOB rods are represented with different colors. The color gradient changes from light to dark with
increasing item number. Since this number is given starting from phi=0
up to phi=360, it is possible to control that DetUnitId are correct.
The packed DetUnitId is written on the first line below. The second line
gives the same information unpacked. For example if you move the mouse on the
first module of the first petal backward for TEC 1 +z you get:
Module key 907004 DetUnitId 1C8181F4
TEC -z layer1 ring 7 petal 1 backward module 1 backward
The module key is instead used in the trackermap software to identify a
module with a unique number giving its position (ring,module) in one of
the 43 layers. It contains these informations packed in the following way module+ring*1000+layer*100000 : in this case module 7 of ring 7 of layer 9.
These instead are the first separated and overlayed trackermaps
obtained with IGUANACMSSW (CMSSW_0_2_0).
This version of Orca uses cmsim 133.
Total number of modules:16540 .
The main difference with April 2002
is that the 4 Tib layers are no more symmetrical.Also , the "holes" in Tib1-4
in the "separated" modules map are due to the fact that Tib rings have different
radii thus requiring different numbers of modules to cover the 360 degrees.
These two images of the Tib1 layer taken from the ps files containing the maps, shows
the difference between the representation with overlayed modules and separated modules.
In the overlayed representation the modules keep their relative position: so you can see clearly how rings overlap in space.But there is no way to see stereo modules and
it is difficult to count them. In the "separated modules" representation, each module
is a different polygon and you can see clearly that the whole layer has double modules (the blue triangles represent stereo modules).
Also, adjacent rings have different number of modules.
The following pictures show instead a single event(with a single track)
first in 3D window then in 2D map with overlayed and separated modules.
These images of TEC6 cut from the 2D map in the ps file show the different method of representation of simhits in this map: In the first picture you see the position of the hit
in the disc plane; instead the second picture shows which modules have been hit(in this case 3 modules: a double and a single one).
Now a single event with pileup represented
as a 2D map with overlayed and separated modules. Another event(without pileup) but representing only simhits in the TEC : in this case the 18 layers are
represented one on top of the other.
If we sum the signal coming from around 100 events with no pileup , we get
the following map.
The rechits in a single event are represented in green. Here you can see the rechits in TIB 1.They are represented as a point indicating the centre of the strip for the strip detector. By representing together simhits and rechits , it is possible to check for possible inconsistencies.This is done here in the representation of both simhits and rechits in the same event. and the same in a single layer(TIB1 again)..
By plotting in 3D reconstructed tracks and modules hit by simulated tracks
with associated simhits , it is possible to check why some of the tracks were
ORCA_7_4_0 , ORCA_7_5_0 , ORCA_7_6_0 , ORCA_8_1_1
These versions of Orca use cmsim 133.
No changes from 7_3_0
This version of Orca use cmsim 133.
No changes for the geometry but we have the first tests with simulated data
done using SVG images (to see these you must download th Adobe plugin).
number of simhits for each module for 100,000 random
numbero of rechits for each module for
50 events with pileup( jpeg version also available).
average adc value for each module 4000 random