FLUKA: SCORE
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SCORE
Defines the (generalised) particles producing the stars to be
scored in each region.
Requests scoring of energy deposition in each region.
See also EVENTDAT, THRESHOLd, USRBIN
WHAT(1..4)
: id-numbers identifying the particles or generalised
particles (see 5} for a list of particle numbers).
Depending on the (generalised) particle type, different
quantities are scored in each region (see Notes 3, 4a):
* For hadrons, photons, muons: stars
* For generalised particles 208.0 and 211.0: energy
deposition (Notes 4b, 4c)
* For generalised particles 219.0, 220.0 and 221.0:
fissions (Note 4d)
* For generalised particle 222.0, neutron balance (Note 4e)
* For generalised particles 229.0 and 230.0: unbiased
energy deposition (Note 4f)
= 0.0: no scoring per region of any of the quantities
listed above
Default
: 201.0, 0.0, 0.0, 0.0 (score stars produced by
all particles)
WHAT(5)
, WHAT(6)
, SDUM
: not used
Default
(option SCORE not given): no scoring by region
= 0.0 : no scoring per region of stars or energy deposited
Default
: 201.0, 0.0, 0.0, 0.0 (score stars produced
by all particles)
WHAT(5)
, WHAT(6)
, SDUM
: not used
Default
(option SCORE not given): no star or dose scoring by region
Notes:
1) The possible particle numbers are those listed in 5}, i.e.
-6.0 to 62.0 and 201.0 to 244.0. However, not all particles
can produce stars and will give meaningful results. Selecting
generalised particles 208.0 (energy) or 211.0 ("electromagnetic"
energy, i.e. energy of electrons, positrons and gamma), one can
score deposited energy (proportional to dose).
2) SCORE is one of the oldest FLUKA commands, which has been kept
unchanged because of its simplicity and easiness of use.
On the other hand, because it lacks the flexible memory
allocation of all other scoring options, there is presently
room for only 4 types of particles. Therefore, only the 4 first
valid WHAT-parameters are retained.
3) A star is a hadronic inelastic interaction occurring at an
energy higher than a threshold defined via the option
THRESHOLd (or by default higher than the transport threshold
of the interacting particle). Star scoring, traditionally used
in most high-energy shielding codes, can therefore be considered
as a form of crude collision estimator: multiplication of
star density by the asymptotic value of the inelastic
nuclear interaction length gives the fluence of hadrons
having energy higher than the current threshold. However,
this is meaningful only if the interaction length doesn't
vary appreciably with energy; therefore it is recommended
to set a scoring threshold = 50 MeV (using option THRESHOLd),
since interaction lengths are practically constant above this
energy.
Besides, star densities calculated with a 50 MeV threshold are the
basis of some established radiation protection techniques such as
the omega-factors for estimating material activation (see [Tho88],
p. 106), and the prediction of single isotope yields from the ratio
of partial to inelastic cross section. Note that such techniques
can still be used, although they have been made obsolete by more
accurate modern FLUKA capabilities (commands DCYSCORE, DCYTIMES,
IRRPROFI, RADDECAY, RESNUCLEi).
4) The SCORE card defines the following scoring:
a - scoring by region the density of stars produced by the
selected particles (if applicable, i.e. if the particles
are hadrons - but not low-energy neutrons -, photons or muons, or
families of them). Stars produced by primary particles can be
scored with id-number 210.0 (BEAMPART), all stars with 201.0
(ALL-PART).
Results will be in stars cm-3 per primary particle if region
volumes have been input by setting IVLFLG=3 in the geometry title
card (see 8}), otherwise in stars per region per primary.
b - scoring by region the total energy density, if generalised
particle 208 (ENERGY) has been selected.
Results will be in GeV cm-3 per primary if volumes have
been input, otherwise in GeV per region per primary.
To obtain dose in Gy, multiply GeV/cm3 by 1.602176462E-7/rho
(rho = density in g/cm3).
c - scoring by region the energy density deposited by electrons,
positrons and photons, if generalised particle 211 (EM-ENRGY) has
been selected. Results as in the previous Note.
d - scoring by region of fissions (or fission density), if
generalised particles 219.0 (FISSIONS), 220.0 (HE-FISS) or 221.0
(LE-FISS) have been selected. These generalised particles
refer to all fissions, high-energy fissions and low-energy
neutron fissions respectively.
Results are in fissions/cm3 per primary if volumes are input,
otherwise in number of fissions per primary.
e - scoring by region of the neutron balance (outgoing minus
incoming neutrons), if generalised particle 222.0 (NEU-BALA) has
been selected.
Results are in net number of neutrons per cm3 per primary if
volumes are input, otherwise in net neutrons per primary.
f - generalised particles 229.0 (UNB-ENER) and 230.0 (UNB-EMEN)
are similar respectively to 208.0 (ENERGY) and 211.0 (EM-ENRGY),
with the difference that the energy deposited is scored with
weight 1, independent of the actual weight of the particle. Of
course, the results will have no physical meaning, but in some
circumstances they will provide useful information about the run
itself (for instance in order to optimise biasing).
g - scoring as in all cases above but separately for each primary
event, if the EVENTDAT option is used (see).
5) A more flexible way to score by region stars, deposited energy etc.
is "region binning" by means of option USRBIN, Note 8). However,
note that in that case the results are not normalised per unit
volume.
6) In FLUKA. stars do not include spallations due to annihilating
particles.
7) SCORE does NOT define scoring done via USRBDX, USRBIN, USRCOLL and
USRTRACK.
Example 1:
SCORE 1.0 8.0 209.0 208.0
Example 2:
SCORE 210.0 7.0 211.0
Example 3:
SCORE 220.0 221.0 222.0 215.0
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