Component Manual for the Neutron Ray-Tracing Package McStas, version 3.8.6

12.28  The Union_logger_1D McStas Component

One dimensional Union logger for several possible variables

Identification

Description

Part of the Union components, a set of components that work together and thus sperates geometry and physics within McStas. The use of this component requires other components to be used.

1) One specifies a number of processes using process components 2) These are gathered into material definitions using Union_make_material 3) Geometries are placed using Union_box/cylinder/sphere, assigned a material 4) A Union_master component placed after all of the above

Only in step 4 will any simulation happen, and per default all geometries defined before this master, but after the previous will be simulated here.

There is a dedicated manual available for the Union_components

This logger in particular is not finished. It is supposed to allow several different variables to be histogrammed, but currently only time is supported

A logger will log something for scattering events happening to certain volumes, which are specified in the target_geometry string. By leaving it blank, all geometries are logged, even the ones not defined at this point in the instrument file. If a list og target_geometries is selected, one can further narrow the events logged by providing a list of process names in target_process which need to correspond with names of defined Union_process components.

To use the logger_conditional_extend function, set it to some integer value n and make and extend section to the master component that runs the geometry. In this extend function, logger_conditional_extend[n] is 1 if the conditional stack evaluated to true, 0 if not. This way one can check what rays is logged using regular McStas monitors. Only works if a conditional is applied to this logger.

Input parameters

Parameters in boldface are required; the others are optional.

Name

Unit

Description

Default

target_geometry

string

Comma seperated list of geometry names that will be logged, leave empty for all volumes (even not defined yet)

"NULL"

target_process

string

Comma seperated names of physical processes, if volumes are selected, one can select Union_process names

"NULL"

min_value

1

Histogram boundery for logged value

max_value

1

Histogram boundery for logged value

n1

1

Number of bins in histogram

90

variable

string

Time for time in seconds, q for magnitude of scattering vector in 1/Å.

"time"

filename

string

Filename of produced data file

"NULL"

order_total

1

Only log rays that scatter for the n’th time, 0 for all orders

0

order_volume

1

Only log rays that scatter for the n’th time in the same geometry

0

order_volume_process

1

Only log rays that scatter for the n’th time in the same geometry, using the same process

0

logger_conditional_extend_index

1

If a conditional is used with this logger, the result of each conditional calculation can be made available in extend as a array called "logger_conditional_extend", and one would then acces logger_conditional_extend[n] if logger_conditional_extend_index is set to n

-1

init

string

Name of Union_init component (typically "init", default)

"init"

nowritefile

1

If set, logger will skip writing to disk

0

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