id_dir_types
Monte Carlo Event Direction Distribution Codes
==============================================
The different types of direction distributions used in INGENR and MCG_GENERATOR
are:
ID Mnemonic Description
-- -------- -----------
-n none Give this particle the same direction as particle n
(particle n must have already been generated).
See warning.
10 IDAISO Generate all events isotropically.
20 IDABM Generate events in a beam.
30 IDACC Generate events with the proper directions for CC e-.
See warning
35 IDANC Generate events with the proper directions for NC n.
See warning
40 IDAES Generate events with the proper directions for ES e-.
See warning
50 IDACONE Generate events on a cone.
60 IDAUSR Generate positions using user specified distribution.
70 IDALAS Generate events according to a distribution modelled
by spherical harmonics to 2nd order. Intended for the
laserball. The spherical harmonic coefficients are
given in CALIBRATION_INFO.DAT
80 IDAPTG Generate events using the angular distribution needed
for the (p,t) gamma source i.e. A+B*SIN^2(theta). The
polar axis used is the PTG source axis if it is
enabled otherwise it is the vertical axis of the
detector.
90 IDACAV Generate events randomly within a cone pointing at the
centre of the detector (Useful for generating gammas
from the cavity wall).
Alternatively generate events randomly on the surface
of the cone (Useful for generating muons at a
particular impact parameter regardless of position).
As of SNOMAN 5 events can be generated either inwards
(default) or outwards.
100 IDAPL Generate events with directions taken from a MCPL bank
(see MCPL bank).
110 IDAPLED Generate events in a filled cone using the polynomial
angular distribution needed for the LEDs mounted on
the PSUP steel structure.
120 IDACOSMU Cosmic ray spectrum.
130 IDALSB Generate events on a non-pointlike laserball source,
randomly picking the direction as a cos theta distribution
centered on the radial direction from the center of the
laserball.
140 IDANCDUSR Generate events with given zenith and azimuthal angles
theta and phi. Theta is measured with respect to the z
axis, (i.e. NCD anode) and phi with respect to the radial
vector pointing *towards* the NCD wire.
160 IDAFCONE Generate events uniformly within a cone (as opposed
to IDACONE which generates events on the surface of
a cone)
170 IDALSBA Generate events on a spherical laserball source with
distribution weighted by laserball mask and grid
coefficients as read from LASR bank
Model A ascribes anisotropies to distribution of both
positions and directions
- must be used wth corresponding POS type
180 IDALSBB As above, but Model B ascribes anisotropies to distribution
of positions only
- must be used with corresponding POS type
190 IDALSBC As above, but Model C ascribes anisotropies to distribution
of directions only
- must be used with corresponding POS type
Notes: IDACC, IDAES and IDANC depend both on time and energy. When selecting
this type of distribution make sure that the:-
1) Particle's time = IDTRATE
2) Particle's energy = IDECC, IDEES, or IDENC as appropriate.
For the different distributions there are different input parameters to be
stored in the DIR_PARAM array. These are:
DIR Type Param. # Description
-------- -------- -----------
10 none
20 1,2 Detector theta, phi of beam.
30 1,(2,3,4) 0= time dependent (defined by IDTCCES),
1= fixed date (2= julian date, Ref: 1975 Jan 1, noon),
2= fixed source direction (2=x, 3=y, 4=z).
3= fixed Celestrial Coord (2=RA, 3=DEC, 4=GMST)
10 10=neutrino type (if IDECC also selected, should be
the same)
35 1,(2,3,4) 0= time dependent (defined by IDTCCES),
1= fixed date (2= julian date, Ref: 1975 Jan 1, noon),
2= fixed source direction (2=x, 3=y, 4=z).
3= fixed Celestrial Coord (2=RA, 3=DEC, 4=GMST)
10 10=neutrino type (if IDENC also selected, should be
the same)
40 1,(2,3,4) 0= time dependent (defined by IDTCCES)
1= fixed date (2= julian date, Ref: 1975 Jan 1, noon),
2= fixed source direction (2=x, 3=y, 4=z).
3= fixed Celestrial Coord (2=RA, 3=DEC, 4=GMST)
10 10=neutrino type (if IDEES also selected, should be
the same)
50 1,2,3 x1,y1,z1 of a point at start of vector.
4,5,6 x2,y2,z2 of a point at end of vector.
7 theta. Points 1 and 2 define a direction, the directions
are then distributed on the surface of a cone which makes
an angle theta with this direction.
60 ? User defined.
70 none
80 1 Parameter A
2 Parameter B
3 Proton energy in MeV
90 1 Cosine of the half-angle of the cone.
2 Set to 0. to generate events inside the cone.
Set not equal to 0. to generate events on the
surface of the cone.
3 Set to 0. to generate events towards the center
Set to negative value to generate events outwards
100 none
110 1,2,3,4 Parameter for polynom (angular distribution filling the
cone)
5 maximal theta for the filled cone
120 none
130 1,2,3 x,y,z of laserball centre.
140 1 theta: zenith angle
2 phi: azimuthal angle, measured with respect to radial vector
pointing *towards* NCD anode.
160 1,2,3 x,y,z direction vector for the center of the cone
from (0,0,0) to (x,y,z) (does not have to be a unit vector)
If the x,y,z direction vector is set to 0.,0.,0. then the cone
direction is randomised for each event and recorded in a pre-source
track. If cloning particles e.g. a photon bomb, the cone direction is
only randomised once and then all the cloned particles will be picked
randomly from the same cone.
4 opening angle of the cone (half angle from center) in
degrees
See Note 1
170 none
180 none
190 none
Warning: Specifying a code of -n indicates that the value will be copied from
the outgoing track of interaction number n where n is the interaction
entry number within the MCPI. This can be ambiguous if the
interaction produces multiple outgoing tracks e.g. a beta gamma decay.
In this case the value will be taken from the FIRST outgoing track,
but there is generally nothing significant to track ordering so you
are advised NOT to link back tracks to such interactions.
Note 1
The DIR_PARAM parameters for a filled cone (160) are converted to:-
1..9 (Except word 8) Rotation matrix: Maps point within cone into detector space.
8 Sneaky trick: Word 8 of matrix is identically zero so it is recycled as the logical flag.
= 1. Fixed direction
= 0. Random direction (not yet recorded in a pre-source for this event)
= -1. Random direction (direction has been recorded in a pre-source for this event)
10 Cosine of cone opening angle
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