Output¶

The output of FLUKA consists of:

a main (standard) output, written on logical output unit LUNOUT (pre-defined as 11 by default)
a scratch file, of little interest to the user, written on output unit LUNGEO (16 by default). However, if the rfluka script is used to run FLUKA, this file is automatically deleted by the script at the end of the run
a file with the last random number seeds, unit LUNRAN (2 by default)
a file of error messages (if any), unit LUNERR (15 by default)
any number (including zero) of estimator output files. Their corresponding logical unit number is defined by the user: in case the number chosen coincides with one of the above, in particular LUNOUT, estimator formatted output will appear as part of the corresponding output stream. However, this is not recommended, and it is not allowed anyway in the case of unformatted output. Generally, the user can choose between formatted and unformatted output. Only formatted output is presented here, while unformatted output is described at the end of each option description
possible additional output generated by the user in any user routine, in particular USROUT (see USROUT: USeR OUTput)

Main output¶

The standard, or main, output is made of several different parts:

A banner page
The FLUKA license
A header with the FLUKA version and the time when the output was printed
A straight echo of the input cards.

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 (!)
Geometry output (if not redirected to a separate file, see GEOBEGIN, Note 1). 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 lines, 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 (originally material and biasing assignment to regions, which in FLUKA however are not part of the geometry data). Other information concerns the memory allocation: FPD (Floating Point Data) , INTEGER ARRAY, zone locations (“zone” and “region” in FLUKA have a different meaning than in MORSE). “Code zones” indicates the subregions 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 normalise 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 number 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 Note 4 to option GLOBAL).
Basic nuclear data used in the program

The data reported are nuclear masses and model parameters used by the program. This part of the output is constant and does not depend on the problem input (it is printed even if the calculation is purely electromagnetic and does not depend on nuclear models).
Information on physical models used in the run

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 choses 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
Material quantities related to multiple scattering

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.
Memory allocation information

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.

Table of correspondence between materials used in the run and materials in the low-energy neutron cross section:index:` <single: low energy; neutron, cross section>` library

Example:

  *** Fluka to low en. xsec  material correspondence: printed atomic densities are
      meaningless when used in a compound ***

Fluka medium     Name     Xsec 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; “Xsec medium number” is the material index used internally by the FLUKA low-energy neutron package. Such index is assigned only to library materials actually used in the current problem, unlike “FLUKA media” which can be pre-defined or defined in input, without being actually assigned to any region.

Blackhole and vacuum are always assigned Xsec 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 The FLUKA neutron cross section library and option LOW–MAT).

Information on the low-energy neutron cross sections

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):

If WHAT(4) = 1.0:

For each neutron energy group:
- group energy limits
- average energies
- velocities and momenta corresponding to the group 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 equal to \({\mathrm \sigma(n,n) + 2 \sigma(n,2n) + 3 \sigma(n,3n)}\) etc.

PNUP = upscatter probability
(can be different from zero only if the number of thermal groups is more than one)

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 \(\nu\) (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.

If WHAT(4) = 2.0:

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:
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:
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
If WHAT(4) = 3.0:

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 = \(\cos 33^\circ\)); a probability \(0.8199 - 0.4105 = 0.4094\) to be at \(84^\circ = \arccos(0.1057)\); and a probability \(1.000 - 0.8199 = 0.1801\) to be at \(139^\circ = \arccos(-0.7588)\).

A -1.0000 probability indicates an isotropic distribution.
Table of available particle types

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-numbers are also listed.

An expanded summary of the input:

This part of output summarises the most important input data, decoded and presented in a more colloquial way.

Beam properties

Information given by BEAM and BEAMPOS options, ): type of particle, energy/momentum, direction, etc. If a user SOURCE is used,), it is indicated here
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.
Termination conditions The maximum number of histories and other ending options set in card START are summarised here
Multiple scattering (hadrons and muons) The logical flags printed are related to option MULSOPT with SDUM = GLOBAL or GLOBHAD. The number of single scatterings to be performed at boundary crossing is also printed.
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 Showers”. 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.
Biasing parameters

This table reports several region-dependent biasing and cutoff parameters:
- Particle importances (set by WHAT(1) and WHAT(3) of option BIASING)
- Russian Roulette factor (multiplicity biasing set by 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)
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 binary 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 COMSCW: weighting deposited energy or stars, FLUSCW: weighting fluence, current and yield)
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 (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.
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)).
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 (set with IONFLUCT, WHAT(1) and WHAT(3) ), and threshold for pair production and bremsstrahlung by heavy particles (set with PAIRBREM. ), and threshold for pair ).
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.
Table of correspondence between materials and regions “Correspondence of regions and EMF-FLUKA material numbers and names”

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 the maximum step size for charged particles.
Rayleigh scattering requests

A line of information is printed for each material in which Rayleigh scattering has been activated (option EMFRAY).
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).

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`	\(\longrightarrow\)	Leading Particle Biasing (LPB) (set by `EMF–BIAS` or `EMFCUT` and )
`Ray.`	\(\longrightarrow\)	Rayleigh scattering (set by `EMFRAY` with `WHAT(1)≥ 1.0`, see)
`S(q,Z)`	\(\longrightarrow\)	Compton binding corrections (`EMFRAY` with `WHAT(1)= 1., 3., 4. or 6.`)
`Pz(q,Z)`	\(\longrightarrow\)	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)

Random number generator calls and CPU time for some histories 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) [1].

One of the two lines contains the number of random number generator calls, expressed in hexadecimal format.

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 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
Results of ``SCORE`` option for all regions

Up to 4 different quantities (energy or star density) are printed at one line per region (see SCORE). 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, see IVLFLG = 3 in Geometry Title line, ). Even if SCORE has not been requested a line of zeros is printed for each region.
Statistics of Coulomb scattering

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.

Russian Roulette/Splitting counters (if requested, see BIASING)

If the BIASING option has been used with SDUM = PRINT, the following statistics is printed for each region:

`N. of RR`	\(\Longrightarrow\)	Number of Russian Roulette (RR) operations made on particles entering that region
`<Wt> in`	\(\Longrightarrow\)	Average weight of particles submitted to RR when entering the region
`<Wt> kil`	\(\Longrightarrow\)	Average weight of particles killed by RR when entering the region
`N. of Sp`	\(\Longrightarrow\)	Number of splitting operations made on particles entering the region
`<wt> in`	\(\Longrightarrow\)	Average weight of particles splitted when entering the region
`<Wt> out`	\(\Longrightarrow\)	Average weight of particles after being splitted 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–PROFIle, p,,) or from multiplicity biasing (WHAT(2) in option BIASING) are not accounted for in the counters.

Final global statistics

At the end of a successful run, after a title
```
Summary of FLUKA-xxxx 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 , independently 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 and separately for prompt and radioactive decay radiation. 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 hadron!and muon dE/dx (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 electro-magnetic showers” . 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 which is left after evaporation of nuclei 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 \(^{14}\)N(n,p)\(^{14}\)C reaction. These protons are transported explicitly and their energy losses are accounted for as ionisation losses
- Escaping the system 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 \(^{235}\)U, 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, in EVENTDAT output.

Scratch file¶

The scratch file used by FLUKA is of little importance for most users, and actually is deleted automatically by the rfluka script at the end of a successful run. It is mentioned here only for the sake of completeness.

The file, written on output unit LUNGEO (16 by default) is a simple echo of the Combinatorial Geometry input, in a different format. At input time, FLUKA stores temporarily the geometry data on this file and calculates the length of the various geometry arrays, which must include also additional information (e.g. the DNEAR value for each body, see Note 4 to option GLOBAL). Then the data are retrieved and the final memory allocation takes place.

Random number seeds¶

A file of 97 seeds for the random number generator is written on output unit LUNRAN (2 by default) at the end of each run. The file, which can be read in the next run on an input unit defined by the user with option RANDOMIZe, is written in hexadecimal format. The first line (which is also printed on standard output at the beginning of the calculation) contains the total number of generator calls corresponding to the present file, expressed as two integers I1, I2 in hexadecimal format (2Z8). The actual number of calls is equal to I2*1.E9 + I1. If the difference between the number of calls in two such files is sufficiently large, the two files can be reasonably expected to produce statistically independent runs.

Error messages¶

Most error messages are written on output unit LUNERR (15 by default), interspersed with lines giving the number of random number generator calls identical to those printed on standard output (see Main output above). This file has generally extension .err. Each error message begins with the name of the routine in which it is originated. Some messages, however (especially if fatal) are printed on standard output.

%    You''re unlucky indeed!!!
%    Pemf file is still locked!!!!!!
%

% *** Photon: have you got the right mat. data set?
%

Many error messages (often somewhat cryptic) are printed only for debugging or information purposes and should be of concern to the user unless there is a large number of them: for instance when one of the hadronic event generators fails to conserve some quantity within the strict limits imposed. Example:

%  Eventq: charge/baryon conservation failure with Nucrin 5 4 11 10
   Eventv: ekin+am < pla,ij,igreyt  4.93747684  4.94905223 14 1

The following type of message is also not important, and is especially frequent in runs with photonuclear reactions activated:

*** Umfnst: eexany,eexdel,eexmin,amepar,enenew,np,ikpmx,eexnew,eexmax  0.
    0.002  0.004319  1.11498839  1.09082268 2 0  0.  0.0171591096

Another type of informative message, indicating that a step counter has been reset because it was approaching the upper limit for an integer, is the following:

*** Emfgeo: Ncoun 2000000000

Generally, messages issued by the geometry routines are more important. However, fatal ones are written to standard output, for instance:

EXIT BEING CALLED FROM G1, NEXT REGION NOT FOUND

In such cases, it is recommended to run the geometry debugger (see command GEOEND on page ) to find and correct the error.

The following one indicates a real problem if repeated more than a few times:

 GEOFAR, TXYZ:  1. -0.0721463599 -0.409276348 -0.909553612
    Nfrom, Nreg, X, Y, Z 1001 3 -0.108787724 -1.26878781  8.78769155

Geofar: Particle in region   3 (cell #    0) in position  1.000000000E+00
0.000000000E+00  1.000000000E+00
 is now causing trouble, requesting a step of  6.258867675E-07 cm
 to direction -2.285059979E-01 -9.412338141E-01  2.487245789E-01, error count: 0

[…skipped …]

 Particle index    3 total energy   5.189748600E-04 GeV  Nsurf    0
We succeeded in saving the particle:  current region is n.     2 (cell #    0)

As it can be seen, the program has some difficulty to track a particle in a certain direction, and it tries to fix the problem by “nudging” the particle by a small amount, in case the problem is due to a rounding error near a boundary. If the message appears often, it is recommended to run the geometry debugger centring around the position reported in order to find if there is an error in the geometry description.

Other geometry errors concern particles with direction cosines not properly normalised. This happens often with user routines where the user has forgotten to check that the sum of the squares be = 1.0D0 in double precision. For instance, the following message is generally caused by an inaccurate MAGFLD user routine:

MAGNEW, TXYZ: ...[sum of the squares]... U,V,V: ...[3 cosines]...

A similar message may be issued by the tracking routine GEOFAR:

GEOFAR, TXYZ: ...[sum of the squares]... U,V,V: ...[3 cosines]...
Nfrom, Nreg, X, Y, Z' ...[calling code, region number, particle position]...

Another geometry error message is the following:

****************************************
       GEOMETRY SEARCH ARRAY FULL
****************************************

This message indicates that insufficient memory has been allocated for the “contiguity list” (list of zones contiguous to each zone, see Fixed format region input, Free format region input). This is not an actual error, but it is suggested that the user could optimise computer time by increasing the values of the NAZ variable in the geometry region specifications.

Estimator output¶

Most estimator results can be printed either as unformatted files or as formatted (ASCII) text, on logical output units chosen by the user. The only exception is DETECT, for which only the unformatted option is available, and for which the output unit number cannot be chosen (it is always 17).

If the formatted option is chosen, it is possible to write the estimator output as part of the main output (logical output unit 11). It is also possible to write the results of more than one detector on the same file. However, the task of post-processing analysis programs is easier if estimators of a different kind (e.g. USRBIN and USRBDX), or even detectors with a different structure (e.g. two USRBINs wit a different number of bins), have their outputs directed to separate files.

All the formatted estimator outputs follow the same pattern:

The title of the run (as given in input with option TITLE).
Date and time
Total number of particles followed, and their total weight. (Note that the number of particles is written in format I7, that may be insufficient for very large runs. In this case the value will be replaced by a line of asterisks)

`DETECT` output¶

Option DETECT produces only unformatted output (see DETECT description on for instructions on how to read it). As for all other estimators, a complete description in clear of the requested scoring is printed on the standard output. For instance:

Detector n.   1  "COINC     " , Ecutoff = 3.142E-07 GeV
 1024 energy bins 2.717E-03 GeV wide, from 3.700E-03 to 2.786E+00 GeV
   energy deposition in   1 regions, (n.:   3)
       in coincidence with
   energy deposition in   1 regions, (n.:   4)

Detector n.   2  "ANTICOINC " , Ecutoff = 6.614E-06 GeV
 1024 energy bins 6.704E-03 GeV wide, from 7.300E-03 to 6.872E+00 GeV
   energy deposition in   1 regions, (n.:   4)
       in anti-coincidence with
   energy deposition in   1 regions, (n.:   3)

`EVENTBIN` output¶

Option EVENTBIN produces either unformatted or formatted output. The formatted output is seldom used because of its size (the binning results, similar to those produced by option USRBIN (see USRBIN output below), are printed after each primary event). As for most other estimators, a complete description in clear of the requested scoring is printed also on the standard output. For instance:

Cartesian binning n.   1  "Eventscore" , generalised particle n.  208
   X coordinate: from -1.5000E+02 to  1.5000E+02 cm,    75 bins ( 4.0000E+00 cm wide)
   Y coordinate: from  1.0000E+02 to  2.0000E+02 cm,    50 bins ( 2.0000E+00 cm wide)
   Z coordinate: from -2.0000E+01 to  1.8000E+02 cm,    20 bins ( 1.0000E+01 cm wide)
   data will be printed on unit   21 (unformatted if < 0)
   accurate deposition along the tracks requested
   unnormalised data will be printed event by event

The header of the formatted output is practically identical to that of USRBIN, except for the words “event by event” printed after the total number of particles:

 *****  Title (as provided by input command TITLE)                                        *****

           DATE:  1/ 5/ 5,  TIME:  8:39:44

          Total number of particles to be followed    8000, event by event

1
   Cartesian binning n.   1  "Eventscore" , generalised particle n.  208
      X coordinate: from -1.5000E+02 to  1.5000E+02 cm,    75 bins ( 4.0000E+00 cm wide)
      Y coordinate: from  1.0000E+02 to  2.0000E+02 cm,    50 bins ( 2.0000E+00 cm wide)
      Z coordinate: from -2.0000E+01 to  1.8000E+02 cm,    20 bins ( 1.0000E+01 cm wide)
      Data follow in a matrix A(ix,iy,iz), format (1(5x,1p,10(1x,e11.4)))

      accurate deposition along the tracks requested

The binning matrix is then printed once for each event (8000 times in the above example), every time preceded by a line:

  Binning n:    1, "Eventscore",  Event #:     1, Primary(s) weight  1.0000E+00
................................................................................
  Binning n:    1, "Eventscore",  Event #:  8000, Primary(s) weight  1.0000E+00

As for most other estimators, the matrix is easily read and manipulated by a simple program, using the format reported in the header.

`EVENTDAT` output¶

Option EVENTDAT produces either unformatted or formatted output (see EVENTDAT description for instructions on how to read an unformatted output). Unlike other estimators, no information is printed on standard output.

The formatted output begins with run title and run time, followed by a short information about:

Number of regions
Number of generalised particle distributions requested

Then, for each primary history:

History number
Primary weight
Primary energy

Total energy balance for the current history, made of 12 contributions. Some of them correspond to those found in the final balance printed at the end of the standard output, but in this case no normalisation to the primary weight is made. Note that some of the contributions are meaningful only in specific contexts (e.g. if low-energy neutron transport has been requested). No explanation is given about the meaning of each contribution, which must be found here below in the order they are printed:

1	=	energy deposited by ionisation
2	=	energy deposited by \(\pi^0\), electrons, positrons and photons
3	=	energy deposited by nuclear recoils and heavy fragments
4	=	energy deposited by particles below threshold
5	=	energy leaving the system
6	=	energy carried by discarded particles
7	=	residual excitation energy after evaporation
8	=	energy deposited locally by low-energy neutrons (kerma)
9	=	energy of particles outside the time limit
10	=	energy lost in endothermic nuclear reactions above 50 MeV
11	=	energy lost in endothermic low-energy neutron reactions
12	=	missing energy

Energy or stars (depending on the generalised particle scoring distribution) deposited or produced in each region during the current history
Random number generator information to be read in order to reproduce the current sequence (skipping calls)

Example:

  **** Event-Data ****
 Energy deposition by protons in PbWO4
 DATE:  1/ 5/ 5,  TIME: 17:42:33
  No. of regions. 3  No. of distr. scored 1

  Event # 1
  Primary Weight  1.  Primary Energy  2. GeV
      Contributions to the energy deposition
     (GeV not normalised to the weight):
 0.519268453  0.963951886  0.183623865  0.  0.  0.0999941751  0.  0.0797502846
 0.  0.  0.  0.153411314
     Generalised scoring distribution # 208
     from first to last region:
 0.  0.109102778  1.6374917
  Seeds after event # 1
***  FADB81       0       0       0       0       0 33B49B1       0       0       0***

  Event # 2
  Primary Weight  1.  Primary Energy  2. GeV
      Contributions to the energy deposition
     (GeV not normalised to the weight):
 1.04533529  0.827161014  0.00902671926  0.  0.  0.  0.  0.0179061908  0.  0.
 0.  0.100570783
     Generalised scoring distribution # 208
     from first to last region:
 0.  0.00186400011  1.89756525
  Seeds after event # 2
*** 1034722       0       0       0       0       0 33B49B1       0       0       0***
......................................................................................

`RESNUCLEi` output¶

Option RESNUCLEi produces either formatted or unformatted output. For the latter, see RESNUCLEi description for instructions on how to read it.

The formatted output begins with the same heading as the standard output (run title and run time), followed by a short information about:

Total number of primary particles followed
Total weight of the primaries
Number and name of the residual nuclei detector, type of reactions considered (high energy or low energy only, or all), region number
Detector volume in cm\(^3\)
Range of Z and N-Z printed
Tabulation format

The information reported in 3, 4 and 5 is printed also in the expanded input summary on main output (see (g)). For instance:

Res. nuclei n.   1  "Al-Region " , "high" energy products, region n.     3
   detector volume:  1.0000E+00 cm**3
   Max. Z:  86, Max. N-Z:  49 Min. N-Z: -4
   data will be printed on unit   21 (unformatted if < 0)

Res. nuclei n.   2  "Cu-Region " ,  all         products, region n.     4
   detector volume:  1.0000E+00 cm**3
   Max. Z:  33, Max. N-Z:  12 Min. N-Z: -4
   data will be printed on unit  -22 (unformatted if < 0)

On the formatted RESNUCLEi output, the above text is followed by one additional line explaining how to read the result matrix which follows:

Data follow in a matrix A(z,n-z-k), k: -5 format (1(5x,1p,10(1x,e11.4)))

Here is an example of a simple program which can be used to display the same results in a more plain way:

     PROGRAM READRN
     CHARACTER*125 LINE, FILINP, FILOUT
     PARAMETER (MAXZ = 86, MINNMZ = -4, MAXNMZ = 49, K = -5)
     DIMENSION RESULT(MAXZ, MINNMZ-K:MAXNMZ-K)

     WRITE(*,*) "Filename?"
     READ(*,'(A)') FILINP
     OPEN(UNIT=1, FILE=FILINP, STATUS='OLD')
     LQ = INDEX(FILINP,' ') - 1
     FILOUT = FILINP(1:LQ)//'.rn'
     OPEN(UNIT=2, FILE=FILOUT, STATUS='UNKNOWN')

     DO 1 I = 1, 14
        READ(1,'(A)') LINE    !  skip header lines
 1   CONTINUE

     READ(1,100,END=4) RESULT
 4   CONTINUE
     WRITE(2,'(A)')   '   Z   A    Residual nuclei'
     WRITE(2,'(A,/)') '         per cm**3 per primary'
     DO 2 I = 1, MAXZ
        DO 3 J = MINNMZ-K, MAXNMZ-K
           IF(RESULT(I,J) .GT. 0.D0)
    &       WRITE(2,'(2I4,1P, G15.6)') I, J+K+2*I, RESULT(I,J)
 3      CONTINUE
 2   CONTINUE
100  FORMAT(1(5X,1P,10(1X,E11.4)))
     END

`USRBDX` output¶

Option USRBDX produces either formatted or unformatted output (for the latter, see USRBDX description for instructions on how to read it). As for most other estimators, a complete description in clear of the requested scoring is printed also on the standard output. For instance:

Bdrx n.   1  "bxlogchb  " , generalised particle n.  202, from region n.     5 to region n.     6
   detector area:  6.3664E+01 cm**2
   this is a two ways estimator
   this is a fluence like estimator
   logar. energy binning from  1.0000E-11 to  3.0000E+00 GeV,   200 bins (ratio : 1.1413E+00)
   linear angular binning from  0.0000E+00 to  1.2566E+01 sr ,     1 bins ( 1.2566E+01 sr wide )
   data will be printed on unit  -25 (unformatted if < 0)

After the title and date, and one line reporting the total number of particles and their weight, the header of the formatted output is very similar to the above text:

 *****  Test boundary crossing estimator                                                  *****

           DATE: 10/25/ 4,  TIME: 10:32:59

          Total number of particles followed   10000, for a total weight of  1.0000E+04

1

   Bdrx n.   5  "bxlogchf  " , generalised particle n.  202, from region n.     5 to region n.     6
      detector area:  6.3664E+01 cm**2
      this is a two ways estimator
      this is a fluence like estimator
      logar. energy binning from  1.0000E-11 to  3.0000E+00 GeV,   200 bins (ratio : 1.1413E+00)
      linear angular binning from  0.0000E+00 to  1.2566E+01 sr ,     1 bins ( 1.2566E+01 sr wide )
      Data follow in a matrix A(ie,ia), format (1(5x,1p,10(1x,e11.4)))

As for most other estimators, the matrix is easily read and manipulated by a simple program, using the format reported in the header. It can also be cut and pasted into a spreadsheet.

`USRBIN` output¶

Option USRBIN produces either formatted or unformatted output (for the latter, see USRBIN description for instructions on how to read it). As for most other estimators, a complete description in clear of the requested scoring is printed also on the standard output. For instance:

Cartesian binning n.   1  "Cufront   " , generalised particle n.  208
   X coordinate: from -2.1100E-01 to  5.5910E+00 cm,    58 bins ( 1.0003E-01 cm wide)
   Y coordinate: from  0.0000E+00 to  5.4010E+00 cm,    53 bins ( 1.0191E-01 cm wide)
   Z coordinate: from  0.0000E+00 to -1.0000E-03 cm,     1 bins (-1.0000E-03 cm wide)
   data will be printed on unit   21 (unformatted if < 0)
   +/- Y symmetry requested and implemented
   accurate deposition along the tracks requested
   normalised (per unit volume) data will be printed at the end of the run

After the title and date, and one line reporting the total number of particles and their weight, the header of the formatted output is very similar to the above text:

 *****  Roman Pot: box with windows                                                       *****

           DATE: 12/ 8/ 3,  TIME: 15:57:27

          Total number of particles followed   30000, for a total weight of  3.0000E+04

1
   Cartesian binning n.   1  "Cufront   " , generalised particle n.  208
      X coordinate: from -2.1100E-01 to  5.5910E+00 cm,    58 bins ( 1.0003E-01 cm wide)
      Y coordinate: from  0.0000E+00 to  5.4010E+00 cm,    53 bins ( 1.0191E-01 cm wide)
      Z coordinate: from  0.0000E+00 to -1.0000E-03 cm,     1 bins (-1.0000E-03 cm wide)
      Data follow in a matrix A(ix,iy,iz), format (1(5x,1p,10(1x,e11.4)))

      +/- Y symmetry requested and implemented
      accurate deposition along the tracks requested

As for most other estimators, the matrix is easily read and manipulated by a simple program, using the format reported in the header. It can also be cut and pasted into a spreadsheet.

`USRCOLL` output¶

Option USRCOLL produces either formatted or unformatted output (for the latter, see USRTRACK description for instructions on how to read it - the two options produce output with identical format).

As for most other estimators, a complete description in clear of the requested scoring is printed also on the standard output. For instance:

Coll  n.   1  "collogchf " , generalised particle n.  202, region n.     6
   detector volume:  4.0000E+01 cm**3
   Warning! Collision estimators not implemented for electrons/positrons and photons
   logar. energy binning from  1.0000E-11 to  1.0000E+00 GeV,  1000 bins (ratio : 1.0257E+00)
   data will be printed on unit   24 (unformatted if < 0)

After the title and date, and one line reporting the total number of particles and their weight, the header of the formatted output is very similar to the above text:

 *****  Test collision estimator                                                          *****

           DATE:  1/ 5/ 5,  TIME: 18:32:28

          Total number of particles followed  100000, for a total weight of  1.0000E+05

1

   Coll  n.   1  "collogchf  " , generalised particle n.  202, region n.     6
      detector volume:  4.0000E+01 cm**3
      logar. energy binning from  1.0000E-11 to  1.0000E+00 GeV,  1000 bins (ratio : 1.0257E+00)
      Data follow in a vector A(ie), format (1(5x,1p,10(1x,e11.4)))

As for most other estimators, the matrix is easily read and manipulated by a simple program, using the format reported in the header. It can also be cut and pasted into a spreadsheet.

`USRTRACK` output¶

Option USRTRACK produces either formatted or unformatted output (for the latter, see USRTRACK description for instructions on how to read it).

As for most other estimators, a complete description in clear of the requested scoring is printed also on the standard output. For instance:

Track n.   1  "tklogchb  " , generalised particle n.  202, region n.     6
   detector volume:  4.0000E+01 cm**3
   logar. energy binning from  1.0000E-11 to  1.0000E+00 GeV,  1000 bins (ratio : 1.0257E+00)
   data will be printed on unit  -23 (unformatted if < 0)

After the title and date, and one line reporting the total number of particles and their weight, the header of the formatted output is very similar to the above text:

 *****  Test track-length/coll. reading program for the manual                            *****

           DATE: 10/25/ 4,  TIME: 10:32:59

          Total number of particles followed   10000, for a total weight of  1.0000E+04

1

   Track n.   5  "tklogchf  " , generalised particle n.  202, region n.     6
      detector volume:  4.0000E+01 cm**3
      logar. energy binning from  1.0000E-11 to  1.0000E+00 GeV,  1000 bins (ratio : 1.0257E+00)
      Data follow in a vector A(ie), format (1(5x,1p,10(1x,e11.4)))

As for most other estimators, the matrix is easily read and manipulated by a simple program, using the format reported in the header. It can also be cut and pasted into a spreadsheet.

`USRYIELD` output¶

Option USRYIELD produces either formatted or unformatted output (for the latter, see USRYIELD description for instructions on how to read it).

As for most other estimators, a complete description in clear of the requested scoring is printed also on the standard output. For instance:

Yield n.   1  "TotPi+(E) " , generalised particle n.   13, from region n.     3 to region n.     2
   user normalisation:  1.0000E+00, adopted cross section (if any):  1.0000E+00 mb
   logar. 1st variable binning from  1.0000E-03 to  5.0000E+01   100 bins (ratio : 1.1143E+00)
   2nd variable ranges from   0.0000E+00 to  3.1416E+00
   1st variable is: Laboratory Kinetic Energy
   2nd variable is: Laboratory Angle (radians)
   data will be printed on unit   21 (unformatted if < 0)

After the title and date, and one line reporting the total number of particles and their weight, the header of the formatted output is very similar to the above text:

 *****  Yield calculation                                                                 *****

           DATE:  1/ 5/ 5,  TIME: 18:54:19

          Total number of particles followed      10, for a total weight of  1.0000E+01

1

   Yield n.   1  "TotPi+(E) " , generalised particle n.   13, from region n.     3 to region n.     2
      user normalisation:  1.0000E+00, adopted cross section (if any):  1.0000E+00 mb
      logar. 1st variable binning from  1.0000E-03 to  5.0000E+01   100 bins (ratio : 1.1143E+00)
      2nd variable ranges from   0.0000E+00 to  3.1416E+00
      1st variable is: Laboratory Kinetic Energy
      2nd variable is: Laboratory Angle (radians)
      Data follow in a vector A(ie), format (1(5x,1p,10(1x,e11.4)))

As for most other estimators, the matrix is easily read and manipulated by a simple program, using the format reported in the header. It can also be cut and pasted into a spreadsheet.

`USERDUMP` output¶

As a default, no formatted output is available for the USERDUMP option. A description of the unformatted collision file is given in Collision tape. However, the user can modify the MGDRAW user routine as described in MGDRAW: general event interface, to obtain any desired output of selected events in the preferred format.

`RAY` output¶

Tracking RAY pseudo-particles (Use of RAY pseudo-particles) produces only an unformatted file. No formatted output is available.

User-generated output¶

Users can generate their own output in any user routine. However, one special routine, USROUT, has been designed for this purpose. It is called on request by command USROCALL, usually at the end of the run, after command START. The desired output can be printed on the standard output file (logical unit LUNOUT), or on one or more separate files. These can be opened explicitly with a normal Fortran OPEN statement or with a FLUKA OPEN command. Otherwise, any WRITE(xx,...) statement will cause a file to be opened by default with a name fort.xx (ftn.xx on some systems), where xx is a logical unit number. In any case, it is important that the logical unit numbers be ≥ 21 (unit numbers up to 20 are internally reserved for FLUKA).

Output¶

Main output¶

Scratch file¶

Random number seeds¶

Error messages¶

Estimator output¶

DETECT output¶

EVENTBIN output¶

EVENTDAT output¶

RESNUCLEi output¶

USRBDX output¶

USRBIN output¶

USRCOLL output¶

USRTRACK output¶

USRYIELD output¶

USERDUMP output¶

RAY output¶

User-generated output¶

`DETECT` output¶

`EVENTBIN` output¶

`EVENTDAT` output¶

`RESNUCLEi` output¶

`USRBDX` output¶

`USRBIN` output¶

`USRCOLL` output¶

`USRTRACK` output¶

`USRYIELD` output¶

`USERDUMP` output¶

`RAY` output¶