Dear all:
I’m doing a simluation about photon incident in a water-lung-water phantom, the schematic diagram is shown below（first row, left):
The expect central axis dose deposited (in literature, second row, left) is shown below while the simluation I did(second row, right) cannot fit it, especially the in the lungs.
Simulation details: Construction(first row, middle) , Spectrum(first, right)
GPS:
/gps/particle gamma
/gps/pos/type Plane
/gps/pos/shape Square
/gps/pos/centre 0. 0. -142.5 cm
/gps/direction 0 0 1
/gps/pos/halfx 1. cm
/gps/pos/halfy 1. cm
/gps/ene/type Arb
/gps/hist/type arb
/gps/hist/point 0.01 0.001485332
/gps/hist/point 0.1 0.014853323
/gps/hist/point 0.4 0.176383216
/gps/hist/point 0.43 0.187523208
/gps/hist/point 0.5 0.19494987
/gps/hist/point 1.22 0.155959896
/gps/hist/point 2.45 0.09023394
/gps/hist/point 3 0.076123283
/gps/hist/point 4 0.051986632
/gps/hist/point 5 0.030820646
/gps/hist/point 6 0.018566654
/gps/hist/point 7 0.001113999
/gps/hist/inter Exp
Score and run:
/score/create/boxMesh wlw_f2_bx000_7arb_test
/score/mesh/boxSize 8 8 10 cm
/score/mesh/nBin 160 160 200
/score/mesh/translate/xyz 0 0 10 cm
/score/quantity/doseDeposit doseDeposit Gy
/score/close
/run/printProgress 10000
/run/beamOn 10000000
I would be very grateful if experts would take a look and give me some advice.