&DRIFT: TIMING
These are the electrons you wish to select for output. One
can either specify these by a sequence number or with such
keywords as LAST, ONE-BUT-LAST etc.
This should be approximately the threshold of the electronics,
but since electronics usually doesn't trigger on a well
defined electron, one can't obtain a too accurate resolution
from this kind of instruction. If resolution estimates are
required, one should compute signals and process these by
an electronics simulation program.
[Default: only the 5th electron.]
Specifies the time window of all arrival time histograms, both
of the selected electron and of all electrons. If you do not
specify a time window, then all timing histograms are given a
range automatically.
The part of the AREA to be covered by the tracks.
Tracks are generated uniformly over this x-range. The
WEIGHTING-FUNCTION can be used to
assign probabilities to the various x values.
[Default: the entire x-range of the AREA.]
The vertical extent of the tracks. This parameter is less
trivial than it might appear: if the range does not cover
the full acceptance boundaries of the wire, the program
will give wrong results for late electrons. If the range
is chosen too small, the waste of CPU time is considerable
and also the accuracy may suffer if the LINES
parameter does not compensate.
[Default: the entire y-range of the AREA.]
The range of angles of the tracks with respect to the vertical.
Tracks will be generated according to a uniform distribution
over this angular range. The
WEIGHTING-FUNCTION can be used to
attribute a probability to each angle.
One may also enter a single angle if tracks are to be
generated only at that angle.
[Default: only vertical tracks are generated.]
Specifying this option requests the use of Monte Carlo style
drift-line integration in which diffusion is accounted for on
a step by step basis.
Each electron of a cluster is in this case drifted separately.
When using this option, you have to be sure that the time or
distance interval for Monte Carlo integration has been set to
a reasonable value with INTEGRATION-PARAMETERS.
[Default: Runge-Kutta-Fehlberg integration is used.]
Requests that attachment data is taken into account.
[Default: attachment data is not taken into account.]
A function of X (x-coordinate of the track) and ANGLE (the
inclination angle of the track in degrees) which is used to
assign a probability to tracks with a given (x,angle) pair.
Tracks are generated uniformly within the
X-RANGE and the
ANGLE-RANGE.
[Default: a weight of 1 is assigned to each track.]
The number of bins in the histograms used to compute the
time at which the selected histogram has a given probability
to have arrived - the mean arrival time is computed directly
without histogram.
[Default: half of MXLIST, usually 100\ bins.]
This option can be used to store the arrival time histograms
for later study. The histograms are made accessible via global
variable names that are displayed while the command is carried
out (SELECTED and ALL).
You have to declare the Global variables before the loop if
- the instruction is placed in the body of a Do loop and
- these global variables are used in arithmetic, in a
condition of an If_line or a condition of an
If_block.
Declaring is not required if the variables are only used outside
the loop, in procedure Calls, in Say statements or for
substitution in normal input statements.
[Default: histograms are not kept.]
The number of Monte Carlo loops over track generation. These
loops can consume considerable CPU time since the drift times,
diffusion coefficients etc are computed for each drift-line
individually (in contrast the ARRIVAL which uses interpolation).
[Default: 1000.]
Garfield can be asked to output for each track the timing
histograms for all (PLOT-OVERALL) and the selected
electron (PLOT-SELECTED-ELECTRON). Both are by default
not plotted.
The timing histograms for the selected electron and for
all electrons are printed out at your request. In the printout,
additional information such as the mean and width are provided.
These quantities are computed from the entries themselves, not
from the accumulated bin contents. The internal arithmetic is
done in double precision.
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Formatted on 21/01/18 at 16:55.