[neutron-mc] detector output files

Timur Elzhov Timur.Elzhov at jinr.ru
Fri Aug 1 12:03:26 CEST 2003

On Thu, Jul 31, 2003 at 12:26:47PM +0200, Emmanuel Farhi wrote:

> The 'N' data has no physical sense. It is a number of simulation events
> for a given data bin. You basically should not use that data, except if
> you wish to study the simulation statistics and efficiency (see Manual, p
> 41).
> In McStas, a simulation event may be regarded as a pack of neutrons,
> containing 'p' particules. When this event propagates, its 'filling'
> decreases, and the total weight of the pack is the intensity 'I' when
> stored in monitor bins, even if the event is still there (and counts for
> '1' in 'N').
OK! Bu, let's have a look at the exec string of my program:

    ./dn2-guide.out --ncount=1e+06   S=3.0  R0=1.00 ...

and at the output:

    Detector: detect_inc_I=6.77255e+09 detect_inc_ERR=1.1166e+07 detect_inc_N=999931 "inc0003.0.dat"
    Detector: detect_out_I=1.98277e+08 detect_out_ERR=856286 detect_out_N=446104 "out0003.0.dat"

"detect_inc" is detector at the guide entrance, and all the incoming neutrons
are directed to them. But, "detect_inc_N" is likely to correspond to the total
counts of neutrons, not "detect_inc_I". "detect_inc_I" expressed in the
strange units and have values of order of 7-8, while I've simulated 1e+6
neutrons... I obviosly misunderstand something, excuse me please :-)


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