FLUKA: 9.1} Main output
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9.1} Main output
----------------
The standard, or main, output is made of several different parts:
Each input line is echoed in output, but not character by character.
The input WHATs and SDUMs are read, and then written with a different format.
Any alignment error shows up as a number or a character string different
from the one intended: therefore in case of problems checking this part
of the output is more effective than checking the input itself.
Comments are reproduced in output, with the exception of in-line
comments preceded by an exclamation mark (!)
The geometry output (which is part of the standard output by default,
but can be re-directed to a separate file) begins with an echo of
the geometry title and the value of the two input variables IVLFLG
(Input VoLume FLaG) and IDBG (in the original CG a debugging flag,
but now used to select various format lengths).
Then there in an echo of the body and region input, including comment
line, and some lines left over from the original MORSE CG, but which are
of little or no meaning in the context of FLUKA: for instance the arrays
IR1 and IR2 (material and biasing assignment to regions, which in FLUKA
are not part of the geometry data). Other information concerns the memory
allocation: FPD (Floating Point Data), INTEGER ARRAY, zone locations
("zone" and "region" have a different meaning in MORSE, but not in FLUKA).
"Code zones" indicates the sub-regions defined by the input OR operator.
The next sections, "Interpreted body echo" and "Interpreted region echo",
show the numbers assigned by the program to bodies and regions defined by
alphanumerical identifiers (if the traditional fixed format has been used,
these output sections are of little interest).
The interpreted echos are followed by the volumes used to normalize a
possible output from option SCORE. Then, for each region in whose
description the OR operator is used, one line similar to the following is
printed at the end of the geometry output:
*** Region # 2 Dnear according to no overlapping ORs ***
*** Region # 3 Dnear according to possible overlapping ORs ***
This information concerns the possibility that random seed sequences
might not be reproducible, a technical issue which does not affect
the quality of the results but can be important for debugging or other
purposes (see a more detailed explanation in a Note to option GLOBAL).
The data reported are nuclear masses and model parameters used by the
program. This output section is constant and does not depend on the
problem input (it is printed even if the calculation is purely
electromagnetical and does not depend on nuclear models).
The nuclear models used by FLUKA to describe intermediate nuclear
effects and interactions have been continuously improved since 1989.
They are automatically activated if the user chooses the appropriate
defaults. Depending on the latter and on the input options used, an
informative message is issued concerning the presence of the following:
Evaporation from residual nucleus
Production of deexcitation gammas
Transport of heavy evaporation products
High Energy fission
Fermi Break-Up
The values of various quantities used by the FLUKA multiple Coulomb
scattering algorithm are printed for each material and for each type of
charged particle.
Starting and ending location in memory of various arrays dynamically
allocated are printed at different points on main output, depending
on the order of input cards.
materials in the low-energy neutron cross section library.
Example:
*** Fluka to Morse material correspondence: printed atomic densities are
meaningless when used in a compound ***
Fluka medium Name Morse medium atomic density Id. 1 Id. 2 Id. 3
number number ( at/(cm barn) )
1 BLCKHOLE 0 0.0000E+00 0 0 0
2 VACUUM 1000 0.0000E+00 0 0 0
6 CARBON 1 0.0000E+00 6 -2 293
7 NITROGEN 2 0.0000E+00 7 -2 293
8 OXYGEN 3 5.3787E-05 8 16 293
17 LEAD 5 3.2988E-02 82 -2 293
21 ARGON 4 0.0000E+00 18 -2 293
Compounds are not listed in this table, since for the time being the FLUKA
neutron library contains only single elements or nuclides.
"Fluka medium number" refers to the material number given by the user via
WHAT(4)
in option MATERIAL; "Morse medium number" is the material index
used internally by the FLUKA low-energy neutron package (originally
derived from the MORSE code). Such index is assigned only to library
materials actually used in the current problem, unlike "FLUKA media" which
can be predefined or defined in input, without being actually assigned to
any region.
Blackhole and vacuum are always assigned Morse index 0 and 1000.
Atomic densities refer to the material in its elemental form and are
printed as 0.0000E+00 if the corresponding element is used only as part of
a compound.
The last 3 columns in the table are the material identifiers unique to each
library material (see 10} and option LOW-MAT).
If low-energy neutrons are transported, some problem-specific information
may be printed, e.g. materials for which recoil or (n,p) protons are
produced explicitly and not accounted for by kerma factors (usually
hydrogen and nitrogen), or materials for which pointwise cross sections
are used (see LOW-NEUT: WHAT(6)
and Note 5).
This is followed by generic information on the neutron cross section
library used (number of energy groups and angles, number of materials, etc.).
If the user requests a more detailed printout (option LOW-NEUT) the
following information is printed, depending on the value of WHAT(4)
:
WHAT(4)
= 1.:
for each neutron energy group:
- group energy limits
- average energies
- velocities and momenta corresponding to the group energy limits
- energy limits of each gamma group
- thermal neutron velocities
for each material used: availability of residual nuclei information
and, for each neutron energy group:
SIGT = total cross section in barn
SIGST = "scattering" cross section in barn. Actually it is equal
to sigma(n,n) + 2*sigma(n,2n) + 3*sigma(n,3n) etc.
PNUP = upscatter probability (can be different from zero only if
there are several thermal groups)
PNABS = probability of Non-ABSorption (= scattering).
It is = SIGST/SIGT, and can sometimes be > 1 because of
(n,xn) reactions
GAMGEN = GAMma GENeration probability = gamma production cross
section divided by SIGT and multiplied by the average
number of gammas per (n,gamma) reaction
NU*FIS = fission neutron production = fission cross section divided
by SIGT and multiplied by nu, the average number of
neutrons per fission
EDEP = Kerma contribution in GeV per collision
PNEL, PXN, PFISS, PNGAM = partial cross sections, expressed as
probabilities (i.e. ratios to SIGT). In the order:
non-elastic, (n,xn), fission, (n,gamma)
The line: (RESIDUAL NUCLEI INFORMATIONS AVAILABLE), if present,
indicates the possibility to use option RESNUCLEi with
WHAT(1)
= 2.0.
WHAT(4)
= 2.: the same as above plus:
for each material used and for each neutron energy group:
- the downscattering matrix (group-to-group transfer probabilities),
as in the following example:
1 CROSS SECTIONS FOR MEDIA 4
.............................................................
(RESIDUAL NUCLEI INFORMATIONS AVAILABLE)
GROUP....DOWNSCATTER MATRIX
.............................................................
6....0.4927 0.0148 0.0006 0.0012 0.0017 0.0023 0.0028 0.0033
0.0038 0.0045 0.0056 0.0070 0.0087 0.0104 0.0120 0.0134
0.0149 0.0163 0.0175 0.0184 0.0190 0.0193 0.0193 0.0190
0.0185 0.0178 0.0164 0.0329 0.0311 0.0278 0.0247 0.0219
0.0198 0.0158 0.0126 0.0101 0.0112 0.0070 0.0026 0.0008
0.0004 0.0002 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
0.0000 0.0000 0.0000
.............................................................
The above table means: after scattering in material 4 of a neutron
in energy group 6, the probability of getting a neutron in the
same group is 49.27%; that to get a neutron in the following group
(group 7) is 1.48%, in group 8 is 0.06% etc. This matrix,
normalised to 1, gives the relative probability of each neutron
group: but the actual probability PER COLLISION must be obtained
by multiplying by PNABS, the scattering cross section divided by
the total cross section and multiplied by the average number of
neutrons per non absorption reaction.
- neutron-to-gamma group transfer probabilities, for instance:
1 NEUTRON TO GAMMA TRANSFERS FOR MEDIA 6
NEUT GROUP GAMGEN TRANSFER PROBABILITIES
1 1.7749E+00 0.0000 0.0000 0.0000 0.0003 0.0002 0.0004
0.0008 0.0015 0.0027 0.0048 0.0084 0.0144
0.0239 0.0378 0.0686 0.0942 0.0967 0.1125
0.2830 0.1249 0.0625 0.0625
..............................................................
The meaning is similar to that explained above, except that each
number refers to the probability of getting a gamma in the
corresponding gamma group. Again, this matrix, normalised to 1,
gives the relative probability of each gamma group: but the actual
probability PER COLLISION must be obtained by multiplying by
GAMGEN, the gamma production cross section divided by the total
cross section and multiplied by the average number of gammas per
(n,gamma) reaction
WHAT(4)
= 3.: the same as above plus:
for each material used and for each neutron energy group:
Cumulative scattering probabilities and scattering polar angle
cosines as in the following example:
1 SCATTERING PROBABILITIES AND ANGLES FOR MEDIA NUMBER 4
GP TO GP PROB ANGLE PROB ANGLE PROB ANGLE
.............................................................
6 6 0.8736 0.9557 0.9823 0.3741 1.0000 -0.6421
6 7 0.4105 0.8383 0.8199 0.1057 1.0000 -0.7588
6 8 0.4444 0.0001 0.7223 0.7747 1.0000 -0.7746
6 9 0.4444 -0.0001 0.7223 -0.7746 1.0000 0.7746
6 10 0.4444 0.0000 0.7223 -0.7746 1.0000 0.7746
6 11 -1.0000 0.0000 0.0000 0.0000 0.0000 0.0000
6 12 -1.0000 0.0000 0.0000 0.0000 0.0000 0.0000
6 13 -1.0000 0.0000 0.0000 0.0000 0.0000 0.0000
.............................................................
The above table reports 3 discrete angle cosines (corresponding to
a Legendre P5 expansion) for each group-to-group scattering
combination, with the respective cumulative probabilities. For
instance, the line:
6 7 0.4105 0.8383 0.8199 0.1057 1.0000 -0.7588
means that neutron scattering from energy group 6 to group 7
has a 0.4105 probability to be at a polar angle of 33 degrees
(0.8383 = cos(33deg)); a probability (0.8199 - 0.4105) = 0.4094 to
be at 84 degrees = acos(0.1057); and a probability
(1.000 - 0.8199) = 0.1801 to be at 139 degrees = acos(-0.7588).
A -1.0000 probability indicates an isotropic distribution.
This table presents constant properties of all particles transported by
FLUKA (name, id number, rest mass and charge), plus two columns indicating:
- the particles which are discarded, by default (neutrinos) or on user's
request (option DISCARD)
- the particle decay flag (see option PHYSICS, with SDUM
= DECAYS)
The available generalised particles and their id are also listed.
This part of output summarises the most important input data, decoded and
presented in a more colloquial way.
a. Beam properties:
Information given by BEAM and BEAMPOS option: type of particle,
energy/momentum, direction, etc. If a user SOURCE is used, it is
indicated here
b. Energy thresholds:
Particle cutoff energies of hadrons and muons as set by default or by
option PART-THR. Neutron cutoff means the threshold between high
and low-energy (multi-group) neutron treatment. Low-energy neutron
group cutoffs are reported by region in a separate table
(see f. below). Electron and photon cutoffs are also reported in a
separate table (see p. below).
c. Ending conditions
The maximum number of histories and stars and other ending options
set in card START are summarised here
d. Multiple scattering (hadrons and muons):
There is a statement about a Coulomb scattering approximation level,
but only for historical reasons. Presently only level 1 is available.
The logical flags which follow are related to option MULSOPT with
SDUM
= GLOBAL or GLOBHAD. The number of single scatterings to be
performed at boundary crossing is also printed.
e. Treatment of electrons and photons, including multiple scattering
For historical reasons dating from the time when FLUKA was handling
only high-energy particles, this title of this part is
"Electromagnetic Cascades".
The logical flags which follow are related to option MULSOPT with
SDUM
= GLOBAL or GLOBEMF. The number of single scatterings to be
performed at boundary crossing is also printed.
f. Biasing parameters
This table reports several region-dependent biasing and cutoff
parameters:
- Particle importances (set with WHAT(1)
and WHAT(3)
of option
BIASING)
- Russian Roulette factor (multiplicity biasing set with WHAT(2)
of
option BIASING)
- Cutoff group (WHAT(1)
of option LOW-BIAS)
- Group limit for non-analogue absorption (WHAT(1)
of option LOW-BIAS)
- Non-analogue survival probability (WHAT(3)
of option LOW-BIAS)
- Group limit for biased downscattering (WHAT(1)
of option LOW-DOWN)
- Biasing downscattering factor (WHAT(2)
of option LOW-DOWN)
g. Estimators requested
For each requested estimator (USRBIN, USRBDX, USRCOLL, USRTRACK,
USRYIELD, RESNUCLEi, DETECT), a complete description is printed
(detector number, particle type, defining region(s) or binning
limits, number of intervals/bins, area/volume, linear/logarithmic,
type of quantity etc.). If the estimator output file is formatted, the
same information is printed also there in an identical format,
otherwise it is available on the corresponding unformatted file.
Note that the estimator detectors are numbered separately according to
their estimator type (Bdrx n. 1, Bdrx n. 2 etc.; Binning n. 1,
Binning n. 2 etc. - independent from the type of binning - Track n. 1,
Track n. 2 etc.), in the order they appear in input. The estimator type
and the detector number can be passed (as variables ISCRNG and JSCRNG
in COMMON SCOHLP) to the user routines COMSCW and FLUSCW, to allow
different kinds of weighting on the scored quantities, depending on the
detector number (see 13})
h. Materials defined and pre-defined
This table includes all materials pre-defined and not overridden
by the user, plus those defined in the user input via options
MATERIAL and COMPOUND, independent from the fact that they have been
assigned or not to any region.
The different columns report the material number, name, atomic number Z
and atomic weight A (effective Z, A for compounds), density, inelastic
and elastic scattering lengths for the primary particles at the
energy defined by option BEAM (meaningful only for primary hadrons),
radiation length (value not used by the program) and inelastic
scattering length for neutrons at the threshold momentum for
transition to the group treatment (by default 20 MeV unless
overridden by PART-THR).
For compounds, an insert is printed with the element composition, plus
the atom fraction and partial density of each component.
i. dE/dx tabulations (if requested, see DELTARAY)
For each assigned material and for each charged heavy particle
(hadrons, muons, recoil ions) a table is printed with the following
data:
energy, unrestricted stopping power, eta (= beta * gamma), shell
correction, restricted stopping power (according to the threshold
specified by the user with DELTARAY, WHAT(1)
).
j. Other stopping power information
The following is printed for each material used:
gas pressure (if applicable), average excitation energy, effective
Z/A, Sternheimer density effect parameters, delta ray production,
threshold, description level for stopping power fluctuations
description level (set with IONFLUCT, WHAT(1)
and WHAT(3)
),and
threshold for pair production and bremsstrahlung by heavy particles
(set with PAIRBREM).
k. Photonuclear reaction requests
A line of information is printed for each material in which muon
photonuclear interactions have been activated (see MUPHOTON). A
similar information is printed for gamma photonuclear interactions,
with the PHOTONUC flag for the relevant energy ranges.
l. Table of correspondence between materials and regions
This table corresponds to the ASSIGNMAt command and may be useful to
check the material assignment to the various regions, as well as
the regions where a magnetic field is present. The minimum step size
set with option STEPSIZE is also reported. The last column refers to
a maximum step size which has not yet been implemented.
m. Rayleigh scattering requests
A line of information is printed for each material in which Rayleigh
scattering has been activated (option EMFRAY).
n. Fluorescence requests
For each material for which fluorescence X-ray production has been
requested, information about the relevant photoelectric cross
section edges is reported (option EMFFLUO).
o. Table of correspondence between regions and EMF materials/biasing
For each assigned material, this table reports the name, number
(the internal numbering sequence is different in the EMF part of
FLUKA), electron and photon energy cutoffs (set with EMFCUT), and
four logical flags indicating whether some options have ben activated
for the material concerned (T means on, F off). The meaning of the
flags is:
BIAS --> Leading Particle Biasing (LPB) (set by EMF-BIAS or EMFCUT)
Ray. --> Rayleigh scattering (set by EMFRAY with WHAT(1)
= 1., 2.,
4. or 5.)
S(q,Z) --> Compton binding corrections (EMFRAY with WHAT(1)
= 1., 3.,
4. or 6.)
Pz(q,Z) --> Compton Doppler broadening (EMFRAY with WHAT(1)
= 4.
or 6.)
The energy thresholds below which LPB is played for electrons and
photons (WHAT(2)
and WHAT(3)
of EMF-BIAS) are also reported, and so
is the LPB bit-code for selected effects (WHAT(1)
of EMF-BIAS)
During the calculation, a couple of lines is printed time and again
after a certain number of histories (or after each history, depending
on WHAT(5)
of option START). [Occasional warning messages printed
during particle transport are found between the lines, especially
if photonuclear reactions have been activated: they have mainly a
temporary debugging purpose and should be ignored].
One of the two lines contains the number of random number generator
calls, expressed as two integers I1, I2 in hexadecimal format (2Z8).
The actual number of calls is equal to I2*1.E9 + I1.
The second line reports, in the following order: the number of
primary particles handled, the number of particles still to be
handled (with respect to the maximum requested by WHAT(1)
of START),
the number of particles which can still be handled judging from the
average time spent so far, the average time per primary based on the
histories already completed, and the estimated time still available
with respect to WHAT(3)
of START.
The sequence of random number call lines is terminated by a message
(FEEDER is the FLUKA routine which starts every history):
"All cases handled by feeder" if the whole number of particles
requested in START has been completed
"Run termination forced from outside" if the run has been
shortened by the FLUKA "stop file"
"Feeder ended due to timeout" if the time limit has been reached
- see WHAT(6)
of START or system-imposed time limit
Up to 4 different quantities (energy or star density) are printed at one
line per region. The volume used for normalisation is also printed
(equal to 1.0 unless a different value has been input by the user at the
end of the geometry description). Even if SCORE has not been requested
a line of zeros is printed for each region.
The number of scatterings which were not performed or were performed
without LDA (Lateral Displacement Algorithm) because they failed to
satisfy Molière's conditions is reported here. This number is usually
very small compared to the total number of scatterings, also reported.
If single scatterings have been activated, their number is also printed.
If the BIASING option has been used with SDUM
= PRINT, the following
statistics is printed for each region:
"N. of RR" --> Number of Russian Roulette operations made on particles
ENTERING that region
"<Wt> in" --> Average weight of particles submitted to Russian Roulette
when entering the region
"<Wt> kil" --> Average weight of particles killed after being submitted
to Russian Roulette when entering the region
"N. of Sp" --> Number of splitting operations made on particles ENTERING
the region
"<Wt> in" --> Average weight of particles submitted to splitting when
entering the region
"<Wt> out" --> Average weight of particles after being submitted to
splitting when entering the region
Separate counters are printed for hadrons/muons, electrons/photons and
low-energy neutrons (referring to importance biasing requested by BIASING
respectively with WHAT(1)
= 1.0, 2.0 and 3.0, or = 0.0 for all).
The number of RR actually refers to "all particles which have not been
splitted" (a particle crossing a boundary between two regions of equal
importance is submitted neither to RR nor to splitting, but is counted as
if it was a RR).
Therefore, the counters can be used to calculate the following quantities,
useful as a guide to set importances and weight windows:
A = "N. of RR" + "N. of Sp" = total number of particles entering the region
B = ("<Wt> in"_RR * "N. of RR") + ("<Wt> in"_Sp * "N. of Sp") = total
weight of the particles entering the region
B/A = average weight of the particles entering the region
Note that RR and splitting arising from Weight-Window biasing (options
WW-FACTOR, WW-THRESh, WW-PROFI) or from multiplicity biasing (WHAT(2)
in
option BIASING) are not accounted for in the counters.
At the end of a successful run, after a title:
"STATISTICS OF THE RUN"
the following are printed:
- Total number of primary particles
- Total weight of the primary particles (can be different from the
previous one, especially if a user source has been used)
- Total number of stars (hadron inelastic collisions) generated
- Total weight of the stars generated
Note:
this statistics includes ALL hadron inelastic collisions,
independent from any threshold set by option THRESHOLd.
Therefore, this number of stars can be different from that
obtained with SCORE or USRBIN.
- Total number of low energy neutron interactions
- Total weight of the low energy neutron interactions
- Total CPU time used to describe all the histories
- Average CPU time per history
- Maximum CPU time used by a history
- Time left before time limit (if applicable)
A more detailed statistics of different quantities follows, including all
regions. The contribution of each type of particle is given, normalised
per unit weight of beam/source particles and also in percent of the total.
- Stars (inelastic hadron interactions)
- Secondaries created in inelastic hadron interactions
- High-energy fissions
- Decay products
- Decayed particles
For each particle the decay length at the decay position is also
reported (decay length = c * tau, with tau = mean life)
- Particles reaching cutoff energy
- Secondaries created in low-energy neutron interactions
Energy balance.
Each main output ends with a global energy budget. The user should
always check it to make sure that the calculation is not affected by any
unphysical effect or mistake. The budget entries are:
- Total energy "deposited" per unit weight of beam/source particle
"Deposited" means actually "accounted for". This value should
normally be equal to the average energy of the primary particles,
except in the case of abnormal termination before the end of the
first history.
- Energy deposited by by ionisation
This is energy deposited by continuous losses of heavy charged
particles (hadron, muon and ion stopping power). Note that it
depends on several user choices:
=> the thresholds set for delta ray production (energy
transferred to electrons is accounted for in the next entry)
=> the transport thresholds (energy of stopping particles is
counted in a separate entry below)
=> transport of light ion recoils (if not transported, their
energy is deposited at the point of production and is
recorded under a separate entry)
- Energy deposited by electrons and positrons
For historical reasons this is labelled as "by em-cascade". It
may depend on delta ray thresholds (see above)
- Energy deposited by nuclear recoils and heavy fragments
This includes only ions which have not been transported
- Energy of particles below threshold
- Residual excitation energy
This is excitation energy of nucleus which is left after
evaporation and not emitted as prompt gamma de-excitation (e.g.
radioactive decay energy)
- Energy deposited by low energy neutrons
This energy is deposited as kerma at the point of collision. It
does not include the energy of hydrogen proton recoils and
that of protons from the 14N(n,p)14C reaction. These protons are
transported explicitly and their energy losses are accounted for
as ionisation losses.
- Escaping the system
More generally, energy entering the blackhole, whether in the
external region or in other blackhole regions defined by the user
- Energy of discarded particles
(Remember that neutrinos are always discarded by default)
- Energy of particles out of time limit
Can be different from zero only if the TIME-CUT option has been
chosen for at least one type of particles
- Missing energy
This entry is calculated as the difference between the total
energy and the sum of all the other entries. While it is usually
extremely small in pure electromagnetic problems, it can take
substantial values (positive or negative) in problems involving
nuclear reactions. It is usually positive, since most nuclear
reactions are endothermic (very roughly, about 8 MeV are spent to
produce each secondary nucleon). However, most low energy neutron
capture reactions are exothermic, and several MeV per capture are
emitted as gamma rays. In problems with fissile materials such as
235U, the "missing" energy can reach very large negative values.
Note that a similar, but more detailed energy balance can be obtained
event by event with option EVENTDAT. See description below.
The last line of information concerns the maximum number of particles that
have been loaded in stack at any time. It is of little interest to most
users.
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