[Gate-users] gate-voxel_dose_output

[AliAsghar Parach]

Dear gate users,
I have questions about GATE voxel phantom dosimetry:
1-In GATE out put file for absorbed Dose, is it really in terms of cGy?

2-I defined a Vacuum in phantom but it has dose in output file, what is it's
reason?

3-I used a simple spherical voxel phantom  with r=24.6 cm filled with water
and simulate it in GATE4.0.0 in 1 Second.
Then I defined a 50 MBq of 140 keV point source in it's center. The sum of
all voxel doses calculated in this sphere was 2.5718 cGy (according to
gate4.0.0 user's manual).

my calculation for emitted energy was:  (50e6)*(140e3*1.6e-19) Joule
and for absorbed energy: as D=E/m and water density is 1000 kg/m^3 then
E=m*D.
so, E(absorbed energy)=(2.5718e-2)*(4/3*3.14*[r^3]*1000)
Therefor absorbed Energy in voxel phantom is so larger than emitted energy
from the point source in 1 second,whereas, absorbed energy is the part of
emitted energy, is it true?
Help me to find out it's problem,please.

would any one send me a complete reliable macro for dosimetry with/without
camera description?
-- 
Ali Asghar Parach,Ph.D. student in Medical Physics,Tarbiat Modares
University,Tehran,Iran
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