materialScan is not adapted for USE_GEANT4_UNITS

[atolosadelgado]

• OS version: Alma9
• Compiler version: gcc 11.3
• Package version: 1.26
• Goal: distance in proper units

To reproduce the issue, you can load any detector and check distances. This should create a box of 19x19x19 cm3, in a world 30cm x 30cm x 30cm.

git clone https://github.com/atolosadelgado/dd4hep_cube.git
cd dd4hep_cube/
cmake -B build -S . -D CMAKE_INSTALL_PREFIX=install
cmake --build build -- install
export LD_LIBRARY_PATH=$PWD/install/lib:$LD_LIBRARY_PATH
geoDisplay compact/simple_detector.xml 
materialScan ./compact/simple_detector.xml 0 0 300 0 0 -300

I think the units are in mm, but it is written cm. Also, if I remember correctly, the expected output with older versions of DD4hep would be Air-Material-Air when doing this, not Air-Material.

Thank you for your time :)
Alvaro

[andresailer]

• How do you build Dd4hep?
• Why do you think distances are in mm?
• What output do you get?

Edit: more questions

[atolosadelgado]

Hi,

I have attached the cmake cache file of my local DD4hep
CMakeCache.txt

I enabled the build option USE GEANT4 UNITS, maybe it is the problem?

I know that the units are shown in mm and not in cm (as it is said in the output of materialScan) because I build the geometry.

This is the output of materialScan:

$ materialScan ./compact/simple_detector.xml 0 0 300 0 0 -300
DD4hep           WARN  ++ STD conditions NOT defined by client. NTP defaults taken.
 +--------------------------------------------------------------------------------------------------------------------------------------------------
 + Material scan between: x_0 = (   0.00,   0.00, 300.00) [cm] and x_1 = (   0.00,   0.00,-300.00) [cm] : 
 +--------------------------------------------------------------------------------------------------------------------------------------------------
 |     \   Material           Atomic                 Radiation   Interaction               Path   Integrated  Integrated    Material
 | Num. \  Name          Number/Z   Mass/A  Density    Length       Length    Thickness   Length      X0        Lambda      Endpoint  
 | Layer \                        [g/mole]  [g/cm3]     [cm]        [cm]          [cm]      [cm]     [cm]        [cm]     (     cm,     cm,     cm)
 +--------------------------------------------------------------------------------------------------------------------------------------------------
 |     1 Air                    7   14.784   0.0012      305288       719982    205.000   205.00    0.000671    0.000285  (   0.00,   0.00,  95.00)
 |     2 Silicon               14   28.085   2.3300     93.6608     457.5312    190.000   395.00    2.029268    0.415557  (   0.00,   0.00, -95.00)
 +--------------------------------------------------------------------------------------------------------------------------------------------------
 |     0 Average Material      14   28.071   1.1214    194.6515     950.5316    395.000   395.00    2.029268    0.415557  (   0.00,   0.00, -95.00)
 +--------------------------------------------------------------------------------------------------------------------------------------------------

This is the line which defines the box of silicon (it is the only volume),

  Box siSolid(19 * cm / 2.,
              19 * cm / 2.,
              19 * cm / 2.);

Thank you for your time
Alvaro

[andresailer]

USE_GEANT4_UNITS

Yes, that turns the units from cm to mm, but the output of the materialScan command has not been changed to switch when this GEANT4_UNITS flag is turned on.

[atolosadelgado]

I have recompiled without that flag and it is back to normal. Shall we close the issue?

Thank you for your time!!

[andresailer]

we should fix the printouts of the materialScan command when GEANT4_UNITS is on

[MarkusFrankATcernch]

@atolosadelgado Hi Alvaro,
I updated the materialscan. Could you please verify if this is correct ?
I also added the changes of materials to the output (G4 units):

$ materialScan checkout/examples/ClientTests/compact/SiliconBlock.xml -30 0 0 30 0 0
DD4hep           WARN  ++ STD conditions NOT defined by client. NTP defaults taken.
 +--------------------------------------------------------------------------------------------------------------------------------------------------
 + Material scan between: x_0 = (-300.00,   0.00,   0.00) [cm] and x_1 = ( 300.00,   0.00,   0.00) [cm] : 
 +--------------------------------------------------------------------------------------------------------------------------------------------------
 |       \   Material                  Atomic               Radiation   Interaction               Path   Integrated  Integrated    Material
 | Num.   \  Name               Number/Z   Mass/A  Density    Length       Length    Thickness   Length      X0        Lambda      Endpoint/Startpoint
 | Layer   \                             [g/mole]  [g/cm3]     [cm]        [cm]          [cm]      [cm]     [cm]        [cm]     (     cm,     cm,     cm)
 +--------------------------------------------------------------------------------------------------------------------------------------------------
 | (start) Air                         7   14.784   0.0012     30528.8      71998.2      0.000     0.00    0.000000    0.000000  ( -30.00,   0.00,   0.00)
 |       1 Air -> Silicon             14   28.085   2.3300     9.36608      45.7531     23.000    23.00    0.000753    0.000319  (  -7.00,   0.00,   0.00)
 |       2 Silicon -> Air              7   14.784   0.0012  30528.8407   71998.1725      6.000    29.00    0.641363    0.131458  (  -1.00,   0.00,   0.00)
 |       3 Air -> Silicon             14   28.085   2.3300     9.36608      45.7531      2.000    31.00    0.641428    0.131486  (   1.00,   0.00,   0.00)
 |       4 Silicon -> Air              7   14.784   0.0012  30528.8407   71998.1725      6.000    37.00    1.282037    0.262624  (   7.00,   0.00,   0.00)
 |   (end) Air                         7   14.784   0.0012     30528.8      71998.2      0.000     0.00    0.000000    0.000000  ( -30.00,   0.00,   0.00)
 +--------------------------------------------------------------------------------------------------------------------------------------------------
 |         Average Material           14   28.034   0.4670     46.7730     228.1856     60.000    60.00    1.282791    0.262944  (  30.00,   0.00,   0.00)
 +--------------------------------------------------------------------------------------------------------------------------------------------------

for TGeo units I get the same output. All input lengths are in [cm] regardless of the compilation mode:

$ materialScan 
 usage: materialScan compact.xml x0 y0 z0 x1 y1 z1 [-interactive]
 or:    materialScan compact.xml -interactive
        -> prints the materials on a straight line between the two given points (unit is cm) 
        -interactive   Load geometry once, then allow for shots from the ROOT prompt
 NOTE:  ALL lengths in units of [cm]