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The next step is to scan whether the line intersects or not with any rod. This scanning is done,
first, on the outermost radius of a rod. If judged to intersect, the information for the two crossing
points with the circle is inserted into the table by a routine ”INSERT” which finds the positions in the
table for the new two points rearranges the arrays T, IR and IL so that the elements may be in the
geometrical order.
After the insertion, then, the scanning on the inner radius of the same pin rod is continued until
the innermost radius if judged to intersect, otherwise the scanning is transferred to the next pin rod.
After scanning all pin rods, the preliminary trace table is organized for the neutron line illustrated in
Fig.8.1-6a as follows:
Table 7.1-2 Preliminary trace table after scanning all pin rods
k 1 2 3 4 5 6 7 8 9 10 11 12
T l AM lBM
l CM l DM lEM
lFM
lMG
lMH
lMI
l MJ l MK lML
IR 26 16 15 14 13 25 5 6 7 8 26 -
IL - 26 16 15 14 13 25 5 6 7 8 26
The final table is further rearranged as;
• Compose a new array II which keeps the T-Region numbers reduced from the array IR which
keeps S-Region numbers using the correspondence specified in the input. Because of the 60°
rotational symmetry, the common T-Region numbers are assigned to each pin rod region.
• Replace the element of T for the distance between the intersecting point and the point M by the
distance between the two adjacent intersecting points.
Table 7.1-3 Final trace table at return step of geometry routine
k 1 2 3 4 5 6 7 8 9 10 11
T l AB l BC l CD lDE
lEF
lFG
lGH
lHI
l IJ l JK l KL
II 6 4 3 2 1 5 1 2 3 4 6
The information obtained by the geometry routine is the common length of arrays, L0, the arrays T
and II and the modified ρ value; ρ’ measured from the center of the adjacent cell which will be traced
next if the perfect reflective boundary (mirror) condition is selected.
For the case of the mirror condition, the root routine calls repeatedly the same geometry routine
with the adjusted arguments (ρ and ϕ) until the specified number of cells are traced, and concatenates
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