Active detector length is compared with a coverage floor. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

One active cell is below the coverage floor

Active cells 1 with pitch 2 meters give active length 2 meters.

m=LactiveLmin=24=2,failm=L_{\text{active}}\mathbin{-}L_{\min}=2\mathbin{-}4=-2,\quad\text{fail}
Cell latticeFinite cells set the detector length.c0c1c2c3total=8 mactive=2 mcellCount=4 countpitch=2 mtotalLength=8 mactiveCells=1 countactiveLength=2 mactiveFraction=1/4 ratiolayerCount=2 countchannelCount=8 count

Two active cells exactly meet the floor

Active cells 2 with pitch 2 meters give active length 4 meters.

m=LactiveLmin=44=0,passm=L_{\text{active}}\mathbin{-}L_{\min}=4\mathbin{-}4=0,\quad\text{pass}
Cell latticeFinite cells set the detector length.c0c1c2c3total=8 mactive=4 mcellCount=4 countpitch=2 mtotalLength=8 mactiveCells=2 countactiveLength=4 mactiveFraction=1/2 ratiolayerCount=2 countchannelCount=8 count

Three active cells clear the floor

Active cells 3 with pitch 2 meters give active length 6 meters.

m=LactiveLmin=64=2,passm=L_{\text{active}}\mathbin{-}L_{\min}=6\mathbin{-}4=2,\quad\text{pass}
Cell latticeFinite cells set the detector length.c0c1c2c3total=8 mactive=6 mcellCount=4 countpitch=2 mtotalLength=8 mactiveCells=3 countactiveLength=6 mactiveFraction=3/4 ratiolayerCount=2 countchannelCount=8 count