Electromagnetic fields (EEMF_macros.mortran) in DOSRZnrc

[SimulatedWorld2]

I am trying to simulate PDDs with/without magnetic fields. I was thinking of using dosrznrc. Is it possible to use EEMF_macros.mortran with dosrznrc (similar to egs_chamber/cavity)? If so, how can I enable it? I tried to include it in dosrznrc.make and also in makefile, but it doesn't work. Thanks in advance!

Example dosrznrc.make

SOURCES = \
	$(EGS_SOURCEDIR)egsnrc.macros \
	$(EGS_UTILS)timing.macros\
	$(MACHINE_MACROS) \
	$(RANDOM).macros\
	$(EGS_SOURCEDIR)transportp.macros\
        $(EGS_SOURCEDIR)pegs4_macros.mortran\
	$(EGS_UTILS)phsp_macros.mortran $(IAEA_PHSP_MACROS)\
	$(EGS_UTILS)srcrz.macros\
	**$(EGS_SOURCEDIR)EEMF_macros.mortran**  \
	$(USER_CODE).mortran \
	$(RANDOM).mortran \
	$(EGS_UTILS)srcrz.mortran\
	$(EGS_UTILS)ensrc.mortran\
	$(EGS_UTILS)geomrz.mortran\
	$(EGS_SOURCEDIR)get_inputs.mortran\
        $(EGS_SOURCEDIR)get_media_inputs.mortran\
	$(EGS_UTILS)grids.mortran\
	$(EGS_UTILS)nrcaux.mortran \
	$(EGS_UTILS)xvgrplot.mortran \
	$(MACHINE_MORTRAN) \
	$(EGS_SOURCEDIR)egs_utilities.mortran \
	$(EGS_SOURCEDIR)egs_parallel.mortran \
        $(EGS_SOURCEDIR)pegs4_routines.mortran\
	$(EGS_SOURCEDIR)egsnrc.mortran	\

[ftessier]

Yes, it is possible to use EEMF in DOSRZnrc, since it is implemented in the mortran backend. You need to define the EMF parameters in your input file, as detailed in the instructions, section 4. If it does not work as expected, please share a small sample input file so that we can take a look at it.

[SimulatedWorld2]

Thanks for the quick reply! Do I understand it correctly that I don't need to change anything in the Makefile/DOSRZnrc.make-files? Anyway, without change the results are exactly the same with/without magnetic field, with the above change they are very similar. With a monoenergy of 4MeV and B=1.5T in the x-direction, I expect a 2%-ish shift of the PDD to the surface (z-direction), which is obviously not the case. Is there a better way to check if the magnetic field works?

I use the input syntax described in your attached document. I also use this input for egs_chamber/cavity, where it works. It looks like this:

:start MC transport parameter:
    magnetic field = 1.5 , 0, 0 # magnetic field in Tesla
    EM ESTEPE = 0.02
    [...]
:stop MC transport parameter:

The .egsinp file I used is attached. It is essentially the depth-dose example in the "example" folder.

depth_dose_example.txt

[ftessier]

You still need to add $(EGS_SOURCEDIR)EEMF_macros.mortran in dosrznrc.make. One way to check what is happening is to rebuild the geometry with egs++ and use, say, the egs_chamber application to generate particle tracks. Then it is possible to assess the curving of the tracks due to the magnetic field in the viewer!

[rtownson]

To use the enhanced magnetic fields, yes you have to add the EEMF line that you suggested in the Makefile, and recompile. Watch for the output from the compiler:

  -> appending /home/rwtownson/EGSnrc/HEN_HOUSE/src/EEMF_macros.mortran

When running the simulation, watch for the output:

 Magnetic Field [T]                                               1.50      0.00      0.00
 EM ESTEPE                                                        0.02

which I do see when running your input file. That means the magnetic field is being applied. I get different results:

With magnetic field
         0.0000              1000.0000
    0.0000-----------------------
          |IRL  2 IZ   1 IX   1 |
          |T  : 1.033E-11+- 4.4%|
          |T-S: 9.663E-12+- 4.4%|
    2.0000-----------------------
          |IRL  3 IZ   2 IX   1 |
          |T  : 1.370E-11+- 3.7%|
          |T-S: 1.281E-11+- 3.8%|
    4.0000-----------------------
          |IRL  4 IZ   3 IX   1 |
          |T  : 1.323E-11+- 3.8%|
          |T-S: 1.234E-11+- 3.8%|

Without magnetic field
         0.0000              1000.0000
    0.0000-----------------------
          |IRL  2 IZ   1 IX   1 |
          |T  : 1.010E-11+- 4.2%|
          |T-S: 9.463E-12+- 4.3%|
    2.0000-----------------------
          |IRL  3 IZ   2 IX   1 |
          |T  : 1.336E-11+- 3.6%|
          |T-S: 1.251E-11+- 3.6%|
    4.0000-----------------------
          |IRL  4 IZ   3 IX   1 |
          |T  : 1.270E-11+- 3.7%|
          |T-S: 1.188E-11+- 3.7%|
          

[SimulatedWorld2]

Thanks for the clarification, I was a little confused!
I used a higher energy (20MeV) and there I can see a clear shift, the magnetic field definitely works!

Thanks for the quick replies and help!

[rtownson]

Make sure that the magnetic field numbers are separated by commas, not just spaces! This is a requirement for the Mortran codes but not in egs++, so is a very easy mistake to make.