[ <--- prev -- ] [ HOME ] [ -- next ---> ]
defines the coordinates of the centre of the beam spot (i.e. the point from
which transport starts) and the beam direction. Also allows to define some
spatially extended sources.
See also BEAM, BEAMAXES, SOURCE, SPECSOUR
for SDUM = blank or NEGATIVE:
WHAT(1) = x-coordinate of the spot centre. This value is available in COMMON BEAMCM as variable XBEAM. It can be used or modified in subroutine SOURCE if command SOURCE is present in input. Default: 0.0
WHAT(2) = y-coordinate of the spot centre. This value is available in COMMON BEAMCM as variable YBEAM. It can be used or modified in subroutine SOURCE if command SOURCE is present in input. Default: 0.0
WHAT(3) = z-coordinate of the spot centre. This value is available in COMMON BEAMCM as variable ZBEAM. It can be used or modified in subroutine SOURCE if command SOURCE is present in input. Default: 0.0
WHAT(4) = direction cosine of the beam with respect to the x-axis of the beam reference frame (namely the geometry reference frame unless defined differently with BEAMAXES). This value is available in COMMON BEAMCM as variable UBEAM. It can be used or modified in subroutine SOURCE if command SOURCE is present in input. Default: 0.0
WHAT(5) = direction cosine of the beam with respect to the y-axis of the beam reference frame (namely the geometry reference frame unless defined differently with BEAMAXES). This value is available in COMMON BEAMCM as variable VBEAM. It can be used or modified in subroutine SOURCE if command SOURCE is present in input. Default: 0.0
WHAT(6) : not used
SDUM = NEGATIVE means that the direction cosine with respect to z-axis is negative. The value of the direction cosine with respect to the z-axis can be overridden in user routine SOURCE by assigning a value to variable WBEAM in COMMON BEAMCM (make sure that the three cosines are properly normalised so that the sum of their squares is 1.0 in double precision!) Default: beam directed in the positive z-direction
for SDUM = SPHE-VOL:
the command defines a spatially extended source shaped as a spherical shell,
centred at the x,y,z point defined by another BEAMPOS command with SDUM
blank or = NEGATIVE. The particle direction or angular distribution are those
defined by a BEAM or by another BEAMPOS card.
WHAT(1) >= 0.0: radius in cm of the inner sphere defining the shell < 0.0: resets to default Default: 0.0
WHAT(2) > 0.0: radius in cm of the outer sphere defining the shell = 0.0: ignored < 0.0: resets to default Default: 1.0 cm WHAT(3)-WHAT(6): not used
for SDUM = CYLI-VOL:
the command defines a spatially extended source shaped as a cylindrical
shell centred at the x,y,z point defined by another BEAMPOS command with
SDUM blank or = NEGATIVE and with the height parallel to the z axis of
the beam reference frame. The particle direction or angular distribution
are those defined by a BEAM or by another BEAMPOS card.
WHAT(1) >= 0.0: radius in cm of the inner cylinder defining the shell < 0.0: resets to default Default: 0.0
WHAT(2) > 0.0: radius in cm of the outer cylinder defining the shell = 0.0: ignored < 0.0: resets to default Default: 1.0 cm
WHAT(3) >= 0.0: height in cm of the inner cylinder defining the shell < 0.0: resets to default Default: 0.0
WHAT(4) > 0.0: height in cm of the outer cylinder defining the shell = 0.0: ignored < 0.0: resets to default Default: 1.0 cm WHAT(5), WHAT(6): not used
for SDUM = CART-VOL:
the command defines a spatially extended source shaped as a Cartesian
shell centred at the x,y,z point defined by another BEAMPOS command with
SDUM blank or = NEGATIVE and with the sides parallel to the beam reference
frame axes. The particle direction or angular distribution are those
defined by a BEAM or by another BEAMPOS card.
WHAT(1) >= 0.0: length in cm of the x side of the inner parallelepiped defining the shell < 0.0: resets to default Default: 0.0
WHAT(2) > 0.0: length in cm of the x side of the outer parallelepiped defining the shell = 0.0: ignored < 0.0: resets to default Default: 1.0 cm
WHAT(3) >= 0.0: length in cm of the y side of the inner parallelepiped defining the shell < 0.0: resets to default Default: 0.0
WHAT(4) > 0.0: length in cm of the y side of the outer parallelepiped defining the shell = 0.0: ignored < 0.0: resets to default Default: 1.0 cm
WHAT(5) >= 0.0: length in cm of the z side of the inner parallelepiped defining the shell < 0.0: resets to default Default: 0.0
WHAT(6) > 0.0: length in cm of the z side of the outer parallelepiped defining the shell = 0.0: ignored < 0.0: resets to default Default: 1.0 cm
for SDUM = FLOOD:
the command defines a source distribution on a spherical surface, centred
at the x,y,z point defined by another BEAMPOS command with SDUM blank or
= NEGATIVE, such as to produce a uniform and isotropic fluence within the
sphere.
WHAT(1) > 0.0: radius of the sphere in cm = 0.0: ignored < 0.0: resets to default Default: 1/sqrt(pi) cm WHAT(2)-WHAT(6): not used
Default (option BEAMPOS not requested): beam starting at point 0., 0., 0. in the z direction)
Notes:
Examples:
* A beam parallel to the x-axis starting at a point of * coordinates -0.1, 5.0, 5.0 : *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8 BEAMPOS -0.1 5.0 5.0 1.0 0.0 0.0
* A beam perpendicular to the x-axis, with director cosines * 0., 1/sqrt(2), -1/sqrt(2) with respect to x, y and z, * starting at point 0.0, 0.0, 0.0 : *...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8 BEAMPOS 0.0 0.0 0.0 0.0 0.7071068 0.0 NEGATIVE