#define THICKNESS 10
TITLE
gamma attenuation
GLOBAL         1000.       0.0       0.0       0.0        1.       0.0
DEFAULTS                                                              PRECISIO
* ..+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
BEAM         -0.0001       0.0       0.0       0.2       0.2        1.PHOTON
BEAMPOS          0.0       0.0       -1.       0.0       0.0
GEOBEGIN                                                              COMBNAME
    0    0                   MC-CAD
* extvoid
SPH extvoid    0.0 0.0 0.0 10000.
* invoid
SPH invoid     0.0 0.0 0.0 1000.
RPP targ       -10. 10. -10. 10. 0.0 5.
XYP p1         0.0
XYP p2         5.
END
* Reg # 1
* bh; assigned material: Blackhole; mat # (1)
bh           5 +extvoid  -invoid
* Reg # 2
* va; assigned material: Vacuum; mat # (2)
valeft       5 +invoid  -targ+p1
* Reg # 2
* va; assigned material: Vacuum; mat # (2)
varigh       5 +invoid  -targ-p2
* Reg # 2
* va; assigned material: Vacuum; mat # (2)
va3          5 +invoid  -targ-p1 +p2
target       5 +targ
END
GEOEND
MATERIAL         13.              2.6989                              ALUMINUM
ASSIGNMA    BLCKHOLE        bh
ASSIGNMA      VACUUM    valeft       va3
ASSIGNMA    ALUMINUM    target
EMFCUT        -1E-05    1.0E-5       0.1  HYDROGEN  @LASTMAT          PROD-CUT
EMFCUT        -1E-05    1.0E-5              valeft  @LASTREG
USRBDX           -1.  BEAMPART      -21.    target    varigh      100.atten1
USRBDX         0.002    1.0E-5        1.                            1. &
* 1#
RANDOMIZ          1.    12234.
START        100000.
STOP