Hi, everyone

Hi, everyone

I’m new to the system, please forgive if I’m asking dumb questions.

I tried excecute the tutor1 several times, but I got same result everytime, even using different computers.

There’s only 10 electrons passing though 1mm of Ta. Shouldn’t the results from each run be very different from each other? (Because of the random interactions)

Thanks.

Hi everyone

Hi everyone,

I dont know why am I getting this error message? As I was using it before and did not have any problem. Recently, I was using clusters for computing and I did not check it in my PC/Laptop. Now, I am getting this error message!! Please let me know how to fix it! Thank you in advance!!

Hi

Hi,

I want to define my own material (glass), is the density correction file necessary?

medium=SKLO16

rho=2.585

elements=SI,O,AL,B,NA,K,CA,BA,ZN

mass fractions=3.18615E-01,4.35832E-01,4.03554E-03,8.15248E-04,8.28098E-02,5.11579E-02,4.40428E-02,3.72816E-02,2.54097E-02

bremsstrahlung correction=NRC

I’m getting an error when I try to use phantoms greater than 256x256x256 in DOSXYZnrc.

I’m getting an error when I try to use phantoms greater than 256x256x256 in DOSXYZnrc. I have changed IMAX,JMAX,KMAX in dosxyznrc_user_macros.mortran (which I need to be root to do) but when I try to recompile I get the following error messages:

/tmp/ccqFUuLE.o: In function `brmsfz_’:

dosxyznrc_linux64.F:(.text+0xb): relocation truncated to fit: R_X86_64_PC32 against symbol `lbremz_’ defined in COMMON section in /tmp/ccqFUuLE.o

/tmp/ccqFUuLE.o: In function `init_ranmar_’:

dosxyznrc_linux64.F:(.text+0x214): relocation truncated to fit: R_X86_64_PC32 against symbol `randomm_’ defined in COMMON section in /tmp/ccqFUuLE.o

/tmp/ccqFUuLE.o: In function `ranmar_get_’:

dosxyznrc_linux64.F:(.text+0xb39): relocation truncated to fit: R_X86_64_PC32 against symbol `randomm_’ defined in COMMON section in /tmp/ccqFUuLE.o

/tmp/ccqFUuLE.o: In function `master.1.get_input_.part.0′:

dosxyznrc_linux64.F:(.text+0x1435): relocation truncated to fit: R_X86_64_PC32 against symbol `egs_io_’ defined in COMMON section in /tmp/ccqFUuLE.o

/tmp/ccqFUuLE.o: In function `anihtm_’:

dosxyznrc_linux64.F:(.text+0xa20c): relocation truncated to fit: R_X86_64_PC32 against symbol `molvar_’ defined in COMMON section in /tmp/ccqFUuLE.o

dosxyznrc_linux64.F:(.text+0xa257): relocation truncated to fit: R_X86_64_PC32 against symbol `pmcons_’ defined in COMMON section in /tmp/ccqFUuLE.o

/tmp/ccqFUuLE.o: In function `tmxb_’:

dosxyznrc_linux64.F:(.text+0xa2b3): relocation truncated to fit: R_X86_64_PC32 against symbol `molvar_’ defined in COMMON section in /tmp/ccqFUuLE.o

/tmp/ccqFUuLE.o: In function `bhabrm_’:

dosxyznrc_linux64.F:(.text+0xa8f8): relocation truncated to fit: R_X86_64_PC32 against symbol `molvar_’ defined in COMMON section in /tmp/ccqFUuLE.o

dosxyznrc_linux64.F:(.text+0xaa5e): relocation truncated to fit: R_X86_64_PC32 against symbol `pmcons_’ defined in COMMON section in /tmp/ccqFUuLE.o

/tmp/ccqFUuLE.o: In function `amolrm_’:

dosxyznrc_linux64.F:(.text+0xab7d): relocation truncated to fit: R_X86_64_PC32 against symbol `molvar_’ defined in COMMON section in /tmp/ccqFUuLE.o

dosxyznrc_linux64.F:(.text+0xac34): additional relocation overflows omitted from the output

collect2: error: ld returned 1 exit status

make: * [/home/rhochuli/Documents/EGSnrc/EGS_HOME/bin/linux64/dosxyznrc] Error 1

I have been able to change these values for ctcreate and run it without a problem.

Thanks in advance!

Hello everyone

Hello everyone,

I am running simulation in egs_brachy with a variety of media. I am slightly confused as to how the :start muen for medium: block works. For example, if I have a seed inside breast tissue and I want to calculate dose to a layer of skin on the surface of the phantom, would I need muen data for both the breast tissue and the skin for this to work properly? Also, if I define the tissue as breast tissue in my geometry definition but use the following input in the scoring options block:

:start muen for medium:

transport medium = WATER

scoring medium = SKIN

:stop muen for medium:

Does it assign each of the breast tissue voxels muen values for water but with breast tissue interaction cross sections in order to transport the photons through the breast tissue? I am just curious about how the code handles the above input and also if I have a large number of media in my phantom, do I need to import muen data for every medium for the simulation to run properly?

-Steven

I have a question regarding dose normalization using a source collection.

I have a question regarding dose normalization using a source collection. I have compared some simulations to measurements with step-and-shoot beams which have straightforward weighting schemes and found good agreement.

For VMAT, every control point is its own BEAM simulation and the numbers seem a little off. It could be a systematic error with how I’m trying to normalize dose/SP in my cavity so here’s my question:

Say I have two simulations that effectively achieve the same thing. Both contain identical simulation geometries, variance reduction, etc. but only differ in the source. In both cases, the source is a collection of 3 MLC-defined fields from a linac. Field 1 comes at gantry 0, Field 2 comes at gantry 270, and Field 3 comes at gantry 180.

Simulation A uses BEAMnrc input files as shared libraries and Simulation B uses phase spaces at the scoring plane created by running those exact same simulations. When I compare the results, they don’t seem to agree with each other. Is that because the normalization between the two scenarios is different or am I just messing something up? In my example, the tracks seem reasonable for both cases (I know phase spaces and BEAM sources come out in separate locations but I believe that’s accounted for looking at the tracks) but the numbers are off by roughly a factor of 3. See the included image (Simulation A on left, Simulation B on right). My first instinct was to just multiply the BEAM collection by the number of sources in the collection but that still doesn’t get me anywhere close to my measurements.

When using source collections of phase spaces for step-and-shoot beams, I never remember needing to normalize by anything other than the total number of monitor units delivered for that plan. Maybe more disturbingly, I’m seeing differences between calculated perturbation ratios in what should amount to identical situations between the source collection using BEAMnrc inputs and the source collection using phase spaces. This shouldn’t be the case if all doses just needed scaling by a single constant right?

Can anyone point me in the right direction of how to compare a measurement to a simulation comprised of a collection BEAMnrc sources in egs_chamber? Thanks!