CONESTAK

CONESTAK consists of a stack of coaxial truncated cones surrounded by a cylindrical wall. The vertices of the cones in each layer do not have to meet but the radii must not decrease as the depth increases. This CM can model scattering foils, primary collimators and many other components. CONESTAK has cylindrical symmetry.

**Figure 22:** CONESTAK with 5 layers (`ISCM_MAX`=5). The outer wall has an inner radius defined by `RBN` and an outer radius equal to the outer boundary of the CM (`RMAX_CM`). Within each layer i, there is a cone with top and bottom radii defined by `RMIN(i)` and `RMAX(i)` respectively. Within each layer, there are three regions: the inner cone, the region between the cone and the outer wall (called the ``outer cone''), and the outer wall. Regions 1,4,7,10,etc specify inner cones; regions 2,5,8,11,etc specify outer cones; and regions 3,6,9,etc specify the outer wall. If the user chooses to have an outer wall (by setting `RBN` 0) then the medium of region 3 , `MED3`, is input first, even before `MED1` and `MED2`, and `MED3` is automatically applied to regions 6,9,etc, so that the outer wall has the same composition in every layer. If the user chooses not to have an outer wall (by setting `RBN` = 0), regions 3,6,9,etc shrink to zero. In specifying radii of cones, the following restrictions apply: `RMAX(i)` $\geq$ `RMIN(i)`, and `RMIN(i+1)` `RMAX(i)`.
$\begin{figure}\begin{center} \leavevmode \mbox{}\hspace{0cm}\epsfysize =11cm \epsffile{conestakd.eps}\end{center}\end{figure}$

The input format for CONESTAK, and an example of input file are given as follows.

CARDS CM_$CONESTAK (CONESTAK Rev 1.8) ******************************** -1 dummy line to indicate start of CM 0 RMAX_CM(ICM_$CONESTAK) (F10.0): Outer radial boundary (cm). 1 TITLE_$CONESTAK (60A1): Title of CM. 2 ZMIN_$CONESTAK, RBN_$CONESTAK (2F15.0): ZMIN_$CONESTAK: Distance from front of first cone to reference plane (Z=0), RBN_$CONESTAK: Inner radius of outer wall (Set to 0 if you do not want an outer wall) 3 ISCM_MAX_$CONESTAK (I5): Number of conical layers Repeat 4 once for I=1,ISCM_MAX_$CONESTAK 4 ZTHICK_$CONESTAK(I), RMIN_$CONESTAK(I), RMAX_$CONESTAK(I) (3F15.0): ZTHICK_$CONESTAK(I): Thickness of conical layer. RMIN_$CONESTAK(I): Front radius of conical layer. RMAX_$CONESTAK(I): Back radius of conical layer. Note restrictions: RMAX_$CONESTAK(I)>=RMIN_$CONESTAK(I) RMIN_$CONESTAK(I+1)>=RMAX_$CONESTAK(I) 5 and 6 are only required if there is an outer wall (ie RBN_$CONESTAK~=0) 5 ECUT, PCUT, DOSE_ZONE, IREGION_TO_BIT in local region 3 (outer wall): (2F15.0,2I5) ECUT, PCUT: Cutoff energies for electrons and photons. DOSE_ZONE: Dose scoring flag, non-zero to score dose deposited in it IREGION_TO_BIT: Bit setting number for the region 6 MED_IN (24A1): Medium of local region 3 used to set MED_INDEX. Repeat 7-10 for each conical layer 7 ECUT, PCUT, DOSE_ZONE, IREGION_TO_BIT in local region 1 (inside cone): (2F15.0,2I5) ECUT, PCUT: Cutoff energies for electrons and photons. DOSE_ZONE: Dose scoring flag, 0 to score dose deposited in it IREGION_TO_BIT: Bit setting number for the region 8 MED_IN (24A1): Medium of local region 1 (inside cone), used to set MED_INDEX 9 ECUT, PCUT, DOSE_ZONE, IREGION_TO_BIT in local region 2 (outside cone): (2F15.0,2I5) ECUT, PCUT: Cutoff energies for electrons and photons. DOSE_ZONE: Dose scoring flag, 0 to score dose deposited in it IREGION_TO_BIT: Bit setting number for the region 10 MED_IN (24A1): Medium of local region 2 (outside of cone), used to set MED_INDEX Example ******* The following input example describes two conical layers. The first layer is a flat-top cone 1.0cm thick, with a radius at the top of 0.8cm and a radius at the base of 1.2cm. The second layer is a cylinder, also 1.0cm thick, of radius 1.2cm. The top cone is made of Cu and the bottom cylinder is made of Pb. The entire structure is encircled by a Pb wall with inner radius 4cm and outer radius 5cm. In both layers, the medium between the cone and the outer wall is H2O. Dose in the Cu cone will be scored in dose zone 1. Dose in the PB cylinder will appear in dose zone 2. The dose to the encircling PB wall will be in zone 3. And the dose to the water in both layers will be scored in zone 4. ECUT and PCUT in all cases is 0.521MeV and 0.01MeV respectively. 5.0 RMAX_CM cone and cylinder surrounded by PB wall 0.0, 4.0 2 1.0, 0.8, 1.2 1.0, 1.2, 1.2 0.521, 0.01, 3, 0 PB 0.521, 0.01, 1, 0 CU 0.521, 0.01, 4, 0 H2O 0.521, 0.01, 2, 0 PB 0.521, 0.01, 4, 0 H2O