Tutorial

This library allows you to create the ShutterValue.txt file the MCP detector needs.

A few parameters must be provided to the command line in order to produce that file.

In order to see the list of arguments required, simply type

> python make_shutter_value_file --help
usage: make_shutter_value_file.py [-h] [--verbose]
                                  [--output_folder OUTPUT_FOLDER]
                                  [--detector_sample_distance DETECTOR_SAMPLE_DISTANCE]
                                  [--detector_offset DETECTOR_OFFSET]
                                  [--resonance_mode RESONANCE_MODE]
                                  [--default_mode DEFAULT_MODE]
                                  epics_chopper_wavelength_range
                                  list_wavelength_dead_time

Generate ShutterValue.txt file used by the MCP detector

optional arguments:
  -h, --help            show this help message and exit
  --verbose, -v         display resulting shutter value file
  --epics_chopper_wavelength_range
                        left,right wavelength range defined by the choppers
  --list_wavelength_dead_time
                        Comma separated list of wavelength that do not have
                        any bragg edges of interest
  --output_folder OUTPUT_FOLDER
                        output folder where the ShutterValue.txt file will be
                        created
  --detector_sample_distance DETECTOR_SAMPLE_DISTANCE
                        Distance detector to sample in m
  --detector_offset DETECTOR_OFFSET
                        Detector offset in micro seconds
  --resonance_mode RESONANCE_MODE
                        Generate shutter value in resonance mode
  --default_mode DEFAULT_MODE
                        Generate default shutter value file

Some of the arguments have default values but you must provide a comma separated range of EPICS chopper wavength range and a comma separated list of wavelength of dead time

EPICS chopper wavelength range (Angstroms)

This comma separated argument (ex: 1,20) represents the range of lambda the chopper are set up. No lambda outside that range won’t be able to be measure.

Example: 1,20

List of wavelength dead time (Angstroms)

This comma separated argument (ex: 3, 5, 8) represents a list of wavelength the program can use to pause the MCP detector. Once defined, the program will set a short interval (0.3A) around that value to pause the MCP detector. Due to the profile of the input beam, make sure you define a dead time in the first 1/3 part of the beam. At least 2 lambda dead time must be provided!

Example: 2,4,8

Verbose

If this flag is provided (–verbose, or -v) the contain of the output file will be displayed in the command line

Output folder

Where to create the ShutterValue.txt file. The current location is used by default

Detector sample distance (m)

The distance in m between the detector and the sample. Default value being 13m

Detector offset (micros)

The offset used by the MCP detector in micros. Default value of 6500micros is used

Resonance mode

If that flag is turned on (–resonance_mode True), the ShutterValue.txt file will be automatically produced using the resonance mode as followed

1e-6    320e-6  3   0.16

Default mode

If that flag is turned on (–default_mode True), the default ShutterValue.txt file will be produced as followed

1e-6    2.5e-3  5   10.24
2.9e-3  5.8e-3  6   10.24
6.2e-3  15.9e-3 7   10.24