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ASSIGNMAt


    defines the correspondence between region indices (or names) and material
    indices (or names). It defines also regions with magnetic and/or electric
    fields. There is the possibility of selectively changing region material to
    vacuum/blackhole (and/or switching on/off possible fields) when transporting
    radioactive decay products. Radioactive decay products originating from
    regions switched to vacuum/blackhole are ignored. This is helpful for
    situations where the emissions of an activated object in a complex
    environment have to be evaluated standalone.

    See also MATERIAL, MGNFIELD

     
WHAT(1)
= material index, or material name No default
WHAT(2)
= lower bound (or name corresponding to it) of the region indices with material index equal or name corresponding to
WHAT(1)
. ("From region
WHAT(2)
...")
Default
= 2.0
WHAT(3)
= upper bound (or name corresponding to it) of the region indices with material index equal or name corresponding to
WHAT(1)
. ("...to region
WHAT(3)
...")
Default
=
WHAT(2)
WHAT(4)
= step length in assigning indices ("...in steps of
WHAT(4)
")
Default
= 1.0
WHAT(5)
= 1.0 : a magnetic field is present (no electric field) in the region(s) defined by
WHAT(2)
, (3), and (4), for both prompt and radioactive decay products = 2.0 : an electric field is present (no magnetic field) in the region(s) defined by
WHAT(2)
, (3), and (4), for both prompt and radioactive decay products = 3.0 : both magnetic and electric fields are present in the region(s) defined by
WHAT(2)
, (3), and (4), for both prompt and radioactive decay products = 4.0 : a magnetic field is present (no electric field) in the region(s) defined by
WHAT(2)
, (3), and (4), for prompt products only = 5.0 : an electric field is present (no magnetic field) in the region(s) defined by
WHAT(2)
, (3), and (4), for prompt products only = 6.0 : both magnetic and electric fields are present in the region(s) defined by
WHAT(2)
, (3), and (4), for prompt products only = 7.0 : a magnetic field is present (no electric field) in the region(s) defined by
WHAT(2)
, (3), and (4), for radioactive decay products only = 8.0 : an electric field is present (no magnetic field) in the region(s) defined by
WHAT(2)
, (3), and (4), for radioactive decay products only = 9.0 : both magnetic and electric fields are present in the region(s) defined by
WHAT(2)
, (3), and (4), for radioactive decay products only = 0.0 : ignored < 0.0 : resets the default (no field) in the region(s) defined by
WHAT(2)
, (3), and (4)
Default
= 0.0 (ignored)
WHAT(6)
= material index, or material name, for a possible alternate material for radioactive decay product transport. Only vacuum and blackhole are allowed. (See Note 5 below).
Default
= same as for prompt products
SDUM
: not used
Default
(option ASSIGNMAt not requested): not allowed! each region must be explicitely assigned a material, or vacuum or blackhole (see Note 3). No magnetic and no electric field is the default for all regions.
Notes:
1) Several ASSIGNMAt definitions are generally necessary to assign a material to all regions. Standard material names and their numbers are listed in 5}. They may be redefined and others may be added (see Note 5 to command MATERIAL) 2) Overlapping region indices can be given in several ASSIGNMAt definitions, each definition overriding the earlier ones. This makes the assigning of materials very convenient (see Example below). The same can be done even if region names are used instead of indices: the region numbers correspond to the order in which they appear in the geometry input. Anyway, the name-index correspondence can be found on standard output after a short test run. 3) Option ASSIGNMAt must always be present. If a region has not been assigned a material, the program stops at initialisation time. Notice that this was different in previous versions of FLUKA, where blackhole was assigned by default. 4) Magnetic field tracking is performed only in regions defined as magnetic field regions by
WHAT(5)
= 1.0, 3.0, 4.0, 6.0, 7.0, 9.0. It is strongly recommended to define as such only regions where a magnetic field actually exists, due to the less efficient and less accurate tracking algorithm used in magnetic fields. To define a region as one with magnetic field and to return systematically B = 0.0 in that region via the user subroutine MAGFLD must be absolutely avoided (see MGNFIELD) 5) There is the possibility of selectively changing regions to vacuum/blackhole (and/or switching on/off possible fields) when transporting radioactive decay products. Radioactive decay products originating from regions switched to vacuum/blackhole are ignored. This is helpful for situations where the emissions of an activated object in a complex environment have to be evaluated standalone. Example (for an input number-based):
*...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....
MATERIAL 13.0 0.0 2.7 10.0 0.0 0.0 ALUMINUM ASSIGNMA 10.0 1.0 15.0 0.0 1.0 0.0 ASSIGNMA 2.0 5.0 17.0 6.0 -1.0 0.0 ASSIGNMA 2.0 16.0 18.0 2.0 0.0 0.0
* The above definitions mean that all regions from 1 to 15 are
* aluminium with a magnetic field, except regions 5 and 11 which are
* vacuum without any magnetic field. Regions 16, 17 and 18 are also
* vacuum without field.
* Note that in the above example material 10 has been defined
* overriding the pre-defined FLUKA aluminium material, but keeping
* the same material number.
The corresponding name-based input cards could be (using arbitrary names): ASSIGNMA ALUMINUM FirstReg Reg15 0.0 1.0 0.0 ASSIGNMA VACUUM FifthReg Reg17 6.0 -1.0 0.0 ASSIGNMA VACUUM Reg16 Reg18 2.0 0.0 0.0

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