For many reasons perhaps not worth getting into, I’m interested in generating two identical phase spaces in both the…

For many reasons perhaps not worth getting into, I’m interested in generating two identical phase spaces in both the standard BEAMnrc and IAEA format. Seemed like something straightforward enough to do until I realized that multiple crossers are treated differently between the two formats.

So no big deal I generated a BEAMnrc phase space as I usually would based on an IMRT beam and then ran it through a 1 nm vacuum (with 5 cm air on the back end so BEAMnrc would be happy) and tallied the phase space again after the 1 nm vacuum region.

The resulting phase spaces are definitely similar but certainly not identical. Something worth noting is that the original BEAMnrc simulation scored a phase space using a 20 cm annulus (ostensibly at the level of my linac’s mylar window).

When I dug into the phase spaces, I noticed that many of the particles appeared to be identical but that several extra particles existed in the BEAMnrc phase space that weren’t in the subsequent IAEA phase space that I was generating using the thin vacuum.

Looking at the X and Y positions of the particles, I see the following (see attached graphs).

Basically, there seem to be particles with positions in the original BEAMnrc phase space that I don’t think should be there since my annulus was set to 20 cm. The resulting IAEA phase space seemed to ignore these “spikes” but as a result the two phase spaces were no longer identical and therefore can’t be compared fairly.

So my initial impression was that the IAEA phase space could be more trustworthy but I can’t fully explain why. I’m going to try to reproduce these spikes by by reversing the process.

I generated these results by doing the following:

Full BEAMnrc simulation creates BEAMnrc PhaseSpace ->

“Fake” BEAMnrc vacuum simulation converts BEAMnrc PhaseSpace to IAEA format

with weird spikes in the original BEAMnrc PhaseSpace

Now I’m currently working on doing the following:

Full BEAMnrc simulation creates IAEA PhaseSpace (same hardware and RNG seeds) ->

“Fake” BEAMnrc vacuum simulation converts IAEA PhaseSpace to BEAMnrc format.

I’ll see if the spikes persist at any point in this simulation too. Has anyone noticed any weird behavior of particles existing in phase spaces outside the specified scoring zone? I guess I can always shrink my annulus too to see if it helps but I wonder why this behavior could happen. Thanks!

Hi there!

Hi there!

I got a fresh *.3ddose file after running a dosxyznrc simulation with a phantom file and phase space file inside.

I was told I need to perform an absolute normalization to read this file (with matlab I guess or something else).

Does anyone have already do this?

Do I need a particular code or a special software to achieve this?

Thank you for your help.

Hi all

Hi all,

When I run the dosxyznrc program, I get the following error message : ” Program received signal SIGSEGV : Segmentatiob fault – invalid memory reference”

Do you know why ? How can I fix it ?

Regards,

Emeric

GNU Fortran (GCC for Simply Fortran) 6.3.0

GNU Fortran (GCC for Simply Fortran) 6.3.0

Using xml test file D:EGSnrc-masterHEN_HOUSEpiecestests_win.xml

===> Checking for availability of system dependent functions

Can the compiler produce object files? ……………….. yes

Can the compiler produce executables? ………………… yes

Does “exit” or “exit_” work properly? ………………… yes [exit]

Compiling “egs_exit.c” since “exit” and “stop” failed ?… yes

Does the “system” function return an exit status ? …….. no

Does the “system” subroutine return an exit status ? …… no

Is “flush” or “flush_” available? ……………………. yes [flush]

Is the “date_and_time” subroutine available ? …………. yes

Is “fdate” or “fdate_” subroutine available? ………….. yes [fdate]

Is “secnds” or “secnds_” function available? ………….. yes [secnds]

Is “date” or “date_” subroutine available? ……………. no

Is “time” or “time_” subroutine available? ……………. no

Is “etime” or “etime_” function available? ……………. yes [etime]

Is function “lnblnk” available? ……………………… yes

Does “hostnm” or “hostnm_” work properly? …………….. yes [hostnm]

Is “lstat” available and does it work properly? ……….. no

Does “inquire” work properly? ……………………….. yes

Compiling a C program to find out the file size ?……… yes

Is record length known? …………………………….. yes [4]

Is “integer*8” available? …………………………… yes [integer*8]

Is “integer*2” available? …………………………… yes [integer*2]

Can endianess of machine be determined?……………….. yes [little endian]

Compiling a C program to find out the name mangling scheme ? yes

Is the name mangling scheme known ?…………………… yes [lower case, _ and _]

********** Tests concluded ! *****

===> Creating C Utilities for EGSnrc…

Building the utilities object file …

Could egs_c_utils.c be compiled? …………………….. yes

Could load_beamlib.c be compiled? ……………………. yes

Could load_vculib.c be compiled? …………………….. yes

Could read_write_pardose.c be compiled? ………………. yes

Testing the C utilities object file …

Could egs_c_utils be linked to a Fortran file ? ……….. yes

Yes, egs_c_utils can be successfully linked to a Fortran file.

Assuming there is no need to pass a flag

to the compiler for opening a DSO on Windows

using Win API function LoadLibrary().

===> Creating configuration file …

===> Creating machine.macros …

* System file D:EGSnrc-masterHEN_HOUSElibwin6432machine.macros successfully created *

===> Creating machine.f …

===> Creating machine.mortran …

* System file D:EGSnrc-masterHEN_HOUSElibwin6432machine.mortran successfully created *

===> Creating dosxyznrc_win6432.spec …

done

===> Appending VCU library to dosxyznrc_win6432.spec …

done

===> Compiling Mortran3 …

Error executing makeEGS_CONFIG=D:EGSnrc-masterHEN_HOUSEspecswin6432.conf

Please tell me how i can complete installation of program

Hi Everyone:

Hi Everyone:

I used Beamnrc to simulate a Varian LINAC, with a score plane after the mirror to generate a phase space file. the fluence VS position figure by Beamdp was shown in the figure. the question is, why are there no result in the red circular part.

Hi Colleagues

Hi Colleagues,

We are planning some IT upgrades – can I please verify whether or not there is any upper limit to the number of processor cores that can be used for batch simulation in the new EGS release (running on the latest Ubuntu, if relevant)?

Many thanks,

Mark

Hi Everyone

Hi Everyone,

Quick question regarding the the beam simulation.

I get a “egsdat” file with both very high and low values and also lots of 0 (mixed)

Moreover, the data switch between lines full of numbers and lines full of zero.

Do you think it is normal ?

Hello everyone!

Hello everyone! There is a discrepancy on SYNCHDMLC and I need some help. On “Define leaf cross-sections” tab, I have a warning that: “Width of bottom support rail must be >= groove+tip width”. However, according to the Varian Monte Carlo data, that is not possible for Quarter Target and Half Target leaves. It is okay for Quarter Isocenter and Target Isocenter leaves. What do you think about that?

Should I just ignore it or is there any solution?

Thanks in advance.

Hello everyone

Hello everyone

I simulated an X-ray beam of 6 MV in BEAMnrc, now I want to calculate the fluence of particles in a water dummy using the phase space in FLURZnrc , what source number should I use to perform the calculation, 21, 22 or 23 and why?

thanks for your help