titles_mcpi
Titles: MCPI
=============
Contact: D. Wark, Oxford.
Revision History:-
================
2.03 D. Wark First version.
2.05 N. West Improve word numbering in this document.
2.06 N. West Add notes about inconsistent usage.
2.08 N. West Replace particle type by interaction code.
Add decay scheme variant and spare slots.
2.09 N. West Correct mistake in the HTML file.
3.00 N. West Add poisson flags (for variable number of particles).
Remove starting date from solar rate.
5.00 S. Peeters Add capability to generate a gaussian random number of particles.
Titles Files
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mc_generator.dat
Verification
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Description
-----------
This bank (MCPI = Monte Carlo Particle Information) contains information for
the different 'particles' (broadly defined) in a simulation.
Data Words
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Fixed length Database Header. See titles_dbhdr.html
Line Type Variable Description
---- ---- -------- -----------
1 I NPART Number of 'particles' in this run.
For each 'particle', all succeeding lines must be repeated.
i+.. i = 0, 67, 134, 201, 268, ...
+2 I INT_TYPE Interaction type. See id_interactions.html for details.
+3 I Decay scheme variant. See note 3.
+4.. I Reserved for future use.
+6 F GAUS_MEAN Gaussian flag mean (setting pois_flg
+7. F GAUS_SIGMA Gaussian flag sigma gaussian settings)
+8 F POIS_FLG Poisson flag for variable number of events:-
= 0.0 Fixed i.e. generate exactly one version.
= +r Variable, generate poisson with a mean of r.
= -r Variable, generate same number as particle -r.
See notes 4 and 5.
+9 I POS_TYPE Position distribution for this particle. See
id_pos_types.html for details.
+10.. F POS_PARAM(1-5) \ | There must be exactly ten total parameters
--| for position generation (on any number of
+15.. F POS_PARAM(6-10) / | lines). See id_pos_types.html for details.
+20 I DIR_TYPE Direction distribution for this particle. See
id_dir_types.html for details.
+21.. F DIR_PARAM(1-5) \ | There must be exactly ten total parameters
--| for direction generation (on any number of
+26.. F DIR_PARAM(6-10) / | lines). See id_dir_types.html for details.
+31 I EN_TYPE Energy distribution for this particle. See
id_en_types.html for details.
+32.. F EN_PARAM(1-5) \ | There must be exactly ten total parameters
--| for energy generation (on any number of
+37.. F EN_PARAM(6-10) / | lines). See id_en_types.html for details.
+42 I TIM_TYPE Time distribution for this particle. See
id_time_types.html for details.
+43.. F TIM_PARAM(1-5) \ | There must be exactly ten total parameters
--| for time generation (on any number of
+48.. F TIM_PARAM(6-10) / | lines). See id_time_types.html for details.
+53 I MISC_TYPE 'Miscellaneous distribution for this particle. This
contains different things for different types of
particles. See id_misc_types.html for details.
+54.. R MISC1_PARAM(1-5) There must be 5 real misc. parameters.
+59.. I MISC2_PARAM(1-5) \ | There must be ten integer parameters
--| for misc generation (on any number of
+64.. I MISC2_PARAM(6-10) / | lines). See id_misc_types.html for details.
Notes
-----
1) The various _param arrays should be padded with zeros to the correct number
of entries. Remember to enter all values as real or integer according to
the type in column two of this table, not according to how they will be used
within the program (INT and FLOAT are used where necessary to get the proper
type within the program when that is different than the type above).
2) Not all combinations of values are valid, see the individual * types
e.g. en types, in ID Codes for details.
There is a specific warning about neutrino interactions.
3) If the interaction code describes a decay scheme, then the bank number
of the standard decay scheme is given by the interaction code but with
ccc = 0. To allow for variants e.g. decay from the isomeric state the
variant word is provided. If the number (=n) held is:-
n > 0, the bank number of the MCDS is given by:-
ttt * 1000000 + ppp * 1000 + n
n < 0, use standard bank. A future development may allow negative n as
a mechanism to hardwire variants into the code.
4) The POIS_FLG allows variable numbers of particles (including zero !) to be
generated. If all particles in an MCPI are variable, it is possible that
the event will be empty (i.e. no seed tracks at all). The flag REJECT_EMPTY
of the MCMA is used to control what happens in this case. The command e.g.:-
$mc_poisson_flag 2.7
can be used to set this flag for the first particle. In this case particle
1 will be generated with poisson statistics and a mean on 2.7 per event.
5) The structure of the MCPI bank allows a user to form connections between
particles i.e. particle B can link back to an earlier particle A for one or
more of its attributes. Care must be taken when doing this with variable
numbers of particles. In general, if A is variable then B cannot link to
it, since there is no way to specify which version of A is being referred to
(and A may not even exists for some events!). The one exception is if B
has the same variablity as A i.e. the POIS_FLG of B is set to -A (or both
POIS_FLGs are negative and point back, directly or indirectly, to a single
"lead" particle with positive POIS_FLG). In this way a tree of particles
can be generated a variable number of times as defined by the lead particle
at the top of the tree.
6) The fission interaction is implemented in a very restrictive way and at
the time of writing simulates only the gammas accompanying the neutrons in
252Cf fission (though it could easily be used to simulate the gammas in
other similar reactions).
In the model for a fission interaction vertex 1 is set to produce a
neutron (and some number of clones) and vertex 2 is set to produce a
'fission'. The 'fission' vertex itself just simulates the fission gammas,
allowing a correlation between their total energy and the total energy of
the neutrons. You can have the fission neutrons without the gammas but not
the fission gammas without the neutrons.
See $SNO_PROD/calibration_252cf.cmd for an example.
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