# Normalization in two step simulation

Dear expert,

Continuing the discussion from Normalization in two steps simulations:

If,
in STEP 1, total no of primary = 5E+9, total primary weight = 1.75E+9, sum of weights in all collision file obtained after STEP1 = 2.03E+3 (this summed collision file has been used as source in STEP 2),

in STEP 2, total no of primary = 2.5 E+9, total primary weight = 2.9E+7.

What will be the multiplication factor that we have to incorporate with the results of STEP 2 ??

Since total histories are different in step 1 and step 2, will they have any effect on this multiplication factor ??

Regards,
Riya

Hello Riya,

As detailed by David in the thread you mentioned above, the multiplication factor to get the correct normalization will simply be the ratio of the recorded primary weight with respect to the total primary weight simulated in step 1. So the most important is to get the correct total primary weight recorded in step 1 that is loaded into step 2. Does the source routine you use write in the .out file of step 2 the weight loaded into step 2?

Cheers,

Andreas

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