I have below error in running a code using tutor7pp.
“Called exit— too many ustep errors”
I wanna to simulate a geometry with multiple radionuclide sources. The output of does scoring is 3ddose.
Any suggestion to solve this problem
I have below error in running a code using tutor7pp.
Published
EGSnrc Google+ Archive 
Excessive ustep errors indicate a problem with the geometry. For example, if you have two surfaces of independent geometries touching, floating point errors may occur. Using egs_view, watching for “fuzzy” or speckled surfaces for definite evidence of a problem.
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R Townson I have used egs_union library to source geometry be in touch with 3D voxlized phantom. The Z dimension of source start from -2 to 0, while 3D phantom start from 0. Is this possible to have overlap in these geometries using egs_union library !?
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Can you describe the geometry better? You only mentioned one geometry, a voxel phantom, so what is it unioned with? The source is not part of the geometry. Perhaps you should inscribe your voxelized phantom in a box of air that also encloses your source location, using egs_envelope.
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I have a voxlized geometry (grid shape) to define source geometry. Some holes in this geometry have radionuclide source. For dose scoring i have a 3D voxlized phantom that created by egs-xyzgeometry class.
You can see my geometry in below imagehttps://lh3.googleusercontent.com/nO5qqENaUEIgInUuBMYm3SWRdr39VLp1VZYSL0rNWoZIdYkongdaANJRo4kTgaeKcjHsN9Rb4AQHU1yr04OarqzqyVzHODo1wdA=s0
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Can you give some better views of the geometry? It looks like there might be a speckled surface in there. You can post your egsinp file if you like.
It sounds like you have two XYZ geometries, and you have combined them using a union. Instead you might want to envelope both XYZ geometries in an air box, and leave a small air gap between the two XYZ geometries so that their surfaces are not touching. Alternatively, you can do this with a CD geometry and 3 planes (similar to the example in the docs). In that case, both of the geometries should be set a bit large/overlapping so that they are “cut to fit” by the CD planes.
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R Townson exactly there are two geometry with xyz library.
Thanks for your valuable comments. I hope to do by your suggestions.
Best Regards
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