Particle and material codes¶
Particles transported by FLUKA¶
Each particle which can be transported by FLUKA is identified by an alphanumeric name and by an integer number. Negative values of such numerical identifiers are reserved to light and heavy ions, and to optical photons. The value 0 indicates a pseudo-particle RAY, which can be used to scan the geometry. Numbers \(>~200\) designate “families” of particles, grouped according to some common characteristics (all hadrons, or all charged particles, etc.). In FLUKA, they are called Generalised Particles and can be used only for scoring. Various forms of scored energy, transferred momentum, induced activity etc. are also treated as Generalised Particles.
The identifier values are reported in Table 5.1 together with the corresponding particle numbering scheme of the Particle Data Group [PDG].
FLUKA name |
FLUKA number |
Symbol |
Common name |
Standard PDG number |
|---|---|---|---|---|
|
|
\(\alpha\) |
Alpha |
— |
|
|
\(^3\)He |
Helium 3 |
— |
|
|
\(^3\)H |
Triton |
— |
|
|
\(^2\)H |
Deuteron |
— |
|
|
— |
Generic Heavy Ion with Z > 2 (see command |
— |
|
|
— |
Optical Photon |
— |
|
|
— |
Pseudoparticle |
— |
|
|
p |
Proton |
|
|
|
p̄ |
Antiproton |
|
|
|
e\(^-\) |
Electron |
|
|
|
e\(^+\) |
Positron |
|
|
|
\(\nu_e\) |
Electron Neutrino |
|
|
|
\(\bar\nu_e\) |
Electron Antineutrino |
|
|
|
\(\gamma\) |
Photon |
|
|
|
n |
Neutron |
|
|
|
n̄ |
Antineutron |
|
|
|
\(\mu^+\) |
Positive Muon |
|
|
|
\(\mu^-\) |
Negative Muon |
|
|
|
K\(^0_L\) |
Kaon-zero long |
|
|
|
\(\pi^+\) |
Positive Pion |
|
|
|
\(\pi^-\) |
Negative Pion |
|
|
|
K\(^+\) |
Positive Kaon |
|
|
|
K\(^-\) |
Negative Kaon |
|
|
|
\(\Lambda\) |
Lambda |
|
|
|
\(\bar\Lambda\) |
Antilambda |
|
|
|
K\(^0_S\) |
Kaon-zero short |
|
|
|
\(\Sigma^-\) |
Negative Sigma |
|
|
|
\(\Sigma^+\) |
Positive Sigma |
|
|
|
\(\Sigma^0\) |
Sigma-zero |
|
|
|
\(\pi^0\) |
Pion-zero |
|
|
|
K\(^0\) |
Kaon-zero |
|
|
|
K̄\(^0\) |
Antikaon-zero |
|
Reserved |
|
— |
— |
— |
|
|
\(\nu_\mu\) |
Muon Neutrino |
|
|
|
\(\bar\nu_\mu\) |
Muon Antineutrino |
|
Blank |
|
— |
— |
— |
Reserved |
|
— |
— |
— |
|
|
\(\bar\Sigma^-\) |
Antisigma-minus |
|
|
|
\(\bar\Sigma^0\) |
Antisigma-zero |
|
|
|
\(\bar\Sigma^+\) |
Antisigma-plus |
|
|
|
\(\Xi^0\) |
Xi-zero |
|
|
|
\(\bar\Xi^0\) |
Antixi-zero |
|
|
|
\(\bar\Xi^-\) |
Negative Xi |
|
|
|
\(\bar\Xi^{+}\) |
Positive Xi |
|
|
|
\(\Omega^-\) |
Omega-minus |
|
|
|
\(\bar\Omega^+\) |
Antiomega |
|
Reserved |
|
— |
— |
— |
|
|
\(\tau^+\) |
Positive Tau |
|
|
|
\(\tau^-\) |
Negative Tau |
|
|
|
\(\nu_\tau\) |
Tau Neutrino |
|
|
|
\(\bar\nu_\tau\) |
Tau Antineutrino |
|
|
|
D\(^+\) |
D-plus |
|
|
|
D\(^-\) |
D-minus |
|
|
|
D\(^0\) |
D-zero |
|
|
|
D̄\(^0\) |
AntiD-zero |
|
|
|
D\(^{+}_{s}\) |
D\(_s\)-plus |
|
|
|
D\(^{-}_{s}\) |
D\(_s\)-minus |
|
|
|
\(\Lambda^{+}_{c}\) |
Lambda\(_c\)-plus |
|
|
|
\(\Xi^{+}_{c}\) |
Xi\(_c\)-plus |
|
|
|
\(\Xi^{0}_{c}\) |
Xi\(_c\)-zero |
|
|
|
\(\Xi^{\prime +}_{c}\) |
Xi\(^{\prime}_{c}\)-plus |
|
|
|
\(\Xi^{\prime 0}_{c}\) |
Xi\(^{\prime}_{c}\)-zero |
|
|
|
\(\Omega^{0}_{c}\) |
Omega\(_c\)-zero |
|
|
|
\(\bar\Lambda^{-}_{c}\) |
Antilambda\(_c\)-minus |
|
|
|
\(\bar\Xi^{-}_{c}\) |
AntiXi\(_c\)-minus |
|
|
|
\(\bar\Xi^{0}_{c}\) |
AntiXi\(_c\)-zero |
|
|
|
\(\bar\Xi^{\prime -}_{c}\) |
AntiXi\(^{\prime}_{c}\)-minus |
|
|
|
\(\bar\Xi^{\prime 0}_{c}\) |
AntiXi\(^{\prime}_{c}\)-zero |
|
|
|
\(\bar\Omega^{0}_{c}\) |
AntiOmega\(_c\)-zero |
|
Reserved |
|
— |
— |
— |
Reserved |
|
— |
— |
— |
Heavy fragments produced in evaporation are loaded in a special stack (
COMMON FHEAVY, contained in theINCLUDEfile with the same name). The internal code for heavy evaporation fragments is the following: 3 = deuteron, 4 = \(^3\)H, 5 = \(^3\)He, 6 = \(^4\)He, 7–12 = fission fragments. Transport capabilities (dE/dx, with account of effective charge and effective charge straggling, multiple Coulomb scattering, no interaction yet) are now available for d, t, \(^3\)He and \(^4\)He. Heavier ions can be transported on demand (see optionIONTRANS), with or without nuclear interactions. Fission fragments and fragments from Fermi break-up, when produced, are also put inCOMMON FHEAVYwith id’s ranging from 7 to 12 (usually 7 and 8 for two fragments).A
RAY is not a real particle, but a straight line trajectory through the FLUKA geometry. When a primary particle, defined by optionsBEAMandBEAMPOSand), or by aSOURCEsubroutine, is found to be aRAY, the program tracks through the geometry in the given direction calculating a number of quantities (distance traversed in each material, number of radiation lengths, number of interaction lengths etc.). See Use of RAY pseudo-particles for instructions about its use
Particle name |
Number |
Description |
|---|---|---|
— |
|
Low-energy neutrons (used only in some input options) |
|
|
All transportable particles |
|
|
All charged particles |
|
|
All neutral particles |
|
|
All negative particles |
|
|
All positive particles |
|
|
Protons and neutrons |
|
|
Protons, neutrons and charged pions |
|
|
For dose scoring: Deposited energy |
For energy fluence scoring: Kinetic energy |
||
|
|
Charged pions |
|
|
Primary (source or beam) particles |
|
|
Electromagnetic energy (of electrons, positrons or photons) |
|
|
Muons |
|
|
Electrons and positrons |
|
|
Antiprotons and antineutrons |
|
|
All kaons |
|
|
All kaons and all hyperons and anti-hyperons (i.e. all strange particles) |
|
|
Charged kaons |
|
|
Charged hadrons |
|
|
Fissions |
|
|
High energy fissions |
|
|
Low energy fissions |
|
|
Neutron balance (algebraic sum of outgoing neutrons minus incoming neutrons |
for all interactions) |
||
|
|
Neutral hadrons |
|
|
Neutral kaons |
|
|
Charmed mesons |
|
|
Charmed (anti)baryons |
|
|
Charmed hadrons |
|
|
Dose (energy deposited per unit mass, GeV/g) |
|
|
Unbiased deposited energy (GeV) \(^{(3)}\) |
|
|
Unbiased electromagnetic energy (of electrons, positrons or photons) (GeV) \(^{(4)}\) |
|
|
X component of momentum transfer (GeV/c) |
|
|
Y component of momentum transfer (GeV/c) |
|
|
Z component of momentum transfer (GeV/c) |
|
|
Activity per unit volume (Bq/cm\(^3\)) \(^{(4)}\) |
|
|
Activity per unit mass (Bq/g) \(^{(4)}\) |
|
|
Silicon 1 MeV-neutron equivalent fluence (cm\(^{-2}\)) |
|
|
Fluence of hadrons with energy > 20 MeV (cm\(^{-2}\)). Unstable hadrons (but neutrons) of |
lower energies are also counted |
||
|
|
Non Ionising Energy Loss deposition (GeV) \(^{(5)}\) |
|
|
Displacements per atoms |
|
|
Dose Equivalent (pSv) \(^{(6)}\) |
|
|
Dose Electromagnetic only (GeV/g) |
|
|
Net charge (in units of elementary electron charge) |
|
|
Dose equivalent with Q(LET) relation (GeV/g) \(^{(7)}\) |
|
|
Restricted above damage threshold NIEL deposition (GeV) \(^{(5)}\) |
|
|
Low-energy (\(E<20\) MeV) neutrons |
|
|
High-energy (\(E>20\) MeV) neutrons |
|
|
All nuclei with mass number at least 2 |
|
|
High energy hadron equivalent fluence (cm\(^{-2}\)) \(^{(8)}\) |
|
|
Thermal neutron equivalent fluence (cm\(^{-2}\)) \(^{(9)}\) |
|
|
Residual nuclei |
|
|
Dose to water |
|
|
Averaged \(\alpha\) coefficient of a linear–quadratic |
dose–effect relationship |
||
|
|
Square root of the averaged \(\beta\) coefficient of a |
linear–quadratic dose-effect relationship |
||
|
|
All ions equal or lighter than alphas included |
|
|
All ions heavier than alphas |
|
|
e\(^{\pm}\) and photons |
|
|
Positron annihilations at rest |
|
|
NRT Displacements per atoms |
|
|
Dose averaged \(LET_\infty\) in water \(^{(10)}\) |
|
|
Auxiliary quantity automatically generated when |
DOSAVLET is selected |
||
|
|
Auxiliary quantity automatically generated when |
DOSAVLET is selected |
||
|
|
Auxiliary quantity automatically generated when |
DOSAVLET is selected |
“Unbiased energy” means that the energy deposited (or the energy fluence) is scored with weight 1, independent of the actual weight of the particle. Of course, the result will have no physical meaning, but in some circumstances it will provide useful information about the run itself (for instance in order to optimise biasing).
“Activity per unit volume” and “Activity per unit mass” are meaningful only when used within a 2D or 3D
USRBINestimator associated (by means of theDCYSCOREoption) with a decay time defined with theDCYTIMESoption. The resulting output units are Bq/cm\(^3\) and Bq/g respectively, unless a binning by region or a special binning is requested, in which case the output is Bq or Bq cm\(^3\)/g.“Non Ionising Energy Loss deposition” describes the energy loss due to atomic displacement (recoil nucleus) as a particle traverses a material. The “Restricted NIEL deposition” gives the same energy loss but restricted to recoils having an energy above the damage threshold defined for each material with the use of
MAT–PROPwithSDUM = DPA–ENER.“Dose equivalent” is computed using various sets of conversion coefficients (see
AUXSCOREfor details) converting particle fluences into Ambient Dose equivalent or Effective Dose. Dose Equivalent of particles for which conversion coefficients are not available, typically heavy ions, can be calculated by scoring generalised particleDOSEQLET.“Dose equivalent” is computed using the \(Q(LET)\) relation as defined in ICRP60, where \(LET\) is \(LET_\infty\) in water.
”High energy hadron equivalent fluence” is proportional to the number of Single Event Upsets (SEU’s) due to hadrons with energy > 20 MeV. Unstable hadrons (but neutrons) of lower energies are also counted. Neutrons of lower energies are weighted according to the ratio of their SEU cross section to the one of > 20 MeV hadrons (substantially reflecting the (n,\(\alpha\)) cross section behaviour in different microchip materials)
”Thermal neutron equivalent fluence” is proportional to the number of SEU’s due to thermal neutrons. Neutrons of higher energies are weighted according to the ratio of their capture cross section to the one of thermal neutrons (following the 1/v law) [Roe11, Roe12].
”Dose averaged LET” is computed multiplying each (charged) particle track segment with its restricted \(LET_\Delta\) in water in order to obtain the corresponding water dose deposition, weighting it with \(LET_\infty\) in water, and dividing the result by water dose deposition as described before, and by the bin volume. Special care is taken for point-like energy depositions (eg particle below threshold) in order to evaluate an approximate residual range and \(LET\). Results are expressed in keV/um. This quantity is available for
USRBINestimators only. Please take into account that each DOSAVLET binning implies the automatic creation of 3 extra binnings with the same dimensions, hence the total memory required is 4 times that of the user requested binning.
Pre-defined materials¶
Materials can be easily defined by option MATERIAL , by assigning a density, a name, a code number (compulsory only if the input has been defined as purely numeric), and, in the case of single elements, an atomic number and an atomic weight. For compounds, the MATERIAL option card must be accompanied by a COMPOUND definition referred to the same material name. If low-energy neutrons (E \(< 20\) MeV) need to be transported, the chosen name of a single element material must coincide with that of one for which cross sections are available (see Table 10.3).
However, for user’s convenience, 25 common single-element materials are already pre-defined (see Table 5.3): they are assigned a default density, name and code number even if no MATERIAL definition has been given. The user can override any of these if desired (but cannot change the code number), and can add more material definitions by means of one or more MATERIAL cards. The only constraints are:
the number sequence of the defined materials must be uninterrupted, i.e. there may not be any gap in the numbering sequence from 25 onwards. If the input is name-based, omitting the material number is the easiest way to ensure this, since the code will assign a correct number automatically.
if one of the pre-defined materials is re-defined using the same name, its code number (if expressed explicitely) must be equal to that of the pre-defined material.
Note that the above constraints can be ignored if the input is name-based and the material number in the MATERIAL option is left blank. In that case, the material name must be used in all relevant command (e.g. ASSIGNMAt, COMPOUND).
In addition to the 25 pre-defined single-element materials, some pre-defined compounds are available. For them, the stopping power of charged particles is not calculated directly from the component elements by the Bragg formula, but the Sternheimer parameters and the ionisation potential recommended by ICRU [ICRU84] are applied. Composition is also that recommended by ICRU. Reference to these pre-defined compounds is normally by name and no MATERIAL and COMPOUND cards are needed: if the input is explicitly number-based only (via command GLOBAL), a number needs to be assigned to them using a MATERIAL card, of course leaving no gaps in the numbering sequence.
FLUKA |
FLUKA |
Common name |
A |
Z |
Density |
|---|---|---|---|---|---|
name |
number |
(g/cm\(^3\)) |
|||
|
|
Blackhole or External Vacuum |
|||
|
|
Vacuum or Internal Vacuum |
|||
|
|
Hydrogen |
1.00794 |
0.0000837 |
|
|
|
Helium |
4.002602 |
0.000166 |
|
|
|
Beryllium |
9.012182 |
1.848 |
|
|
|
Carbon |
12.0107 |
2.000 |
|
|
|
Nitrogen |
14.0067 |
0.00117 |
|
|
|
Oxygen |
15.9994 |
0.00133 |
|
|
|
Magnesium |
24.3050 |
1.740 |
|
|
|
Aluminium |
26.981538 |
2.699 |
|
|
|
Iron |
55.845 |
7.874 |
|
|
|
Copper |
63.546 |
8.960 |
|
|
|
Silver |
107.8682 |
10.500 |
|
|
|
Silicon |
28.0855 |
2.329 |
|
|
|
Gold |
196.96655 |
19.320 |
|
|
|
Mercury |
200.59 |
13.546 |
|
|
|
Lead |
207.2 |
11.350 |
|
|
|
Tantalum |
180.9479 |
16.654 |
|
|
|
Sodium |
22.989770 |
0.971 |
|
|
|
Argon |
39.948 |
0.00166 |
|
|
|
Calcium |
40.078 |
1.550 |
|
|
|
Tin |
118.710 |
7.310 |
|
|
|
Tungsten |
183.84 |
19.300 |
|
|
|
Titanium |
47.867 |
4.540 |
|
|
|
Nickel |
58.6934 |
8.902 |
FLUKA |
Common name |
Density |
|---|---|---|
name |
(g/cm\(^3\)) |
|
|
Water |
1.0 |
|
Polystyrene |
1.06 |
|
Plastic scintillator |
1.032 |
|
Polymethyl methacrylate, Plexiglas, Lucite, Perspex |
1.19 |
|
Compact bone |
1.85 |
|
Cortical bone |
1.85 |
|
Skeletal muscle |
1.04 |
|
Striated muscle |
1.04 |
|
Adipose tissue |
0.92 |
|
Kapton polyimide film |
1.42 |
|
Polyethylene |
0.94 |
|
Dry air at NTP conditions |
0.00120479 |
Physical units¶
Physical quantity |
Unit |
|---|---|
distance |
cm (and derived units cm\(^2\), cm\(^3\) for areas and volumes) |
energy |
GeV Exceptions: eV is used for average ionisation potential and for damage energy threshold input by option g MeV\(^{-1}\) cm\(^{-2}\) is used for the first Birks coefficient input by option |
momentum |
GeV/c |
temperature |
degree Kelvin |
solid angle |
sr (exception: degrees may be used, on user’s request, with option |
magnetic field |
T |
electric field |
MV/m |
time |
s (option |
activity |
Bq |
LET |
keV/(\(\\mu\)\ m g/cm\(^3\)) |
dose equivalent |
pSv |