PTB cookbook

This page contains a summary of the most import commands for Analia's experiment.

Change Sample

One can save the coordinate of the tripod and goniometer for sample changing. The first time drive the sample to the change position manually and once you are happy with the coordinate save them using:

save_sample_position('my_positions')

To drive the tripod and goniometer to the same set of coordinates use:

# to use the default positions
sample_change()

# to use custom positions
sample_change('my_positions')

Finally, to bring the sample to the measuring positions:

sample_measure()

Settle Time

All the motors at the optics beamline have a settle time (a time they wait after the movement is finished before they repor done) of 0.5 seconds. This settle time introduces a delay between the end of the movement and the beginning of the measurement. The delay is expressed in seconds

# settle time for all motors of 2 seconds
settle_time(2)

Keithleys

You can use the gui to visualize the Keithleys on the measuring screen.

Average

When measuring with the Keithleys, it is possible to instruct them to repeat the measurement n times, and return the averaged value.

kth1.avg_type.set('Repeat')
kth1.avg_num.put(5)

Triggers before reading

By default at the Optics beamline the keithleys are triggered three times before being read. Once can change the number of times a keithley is triggered before being read setting the trigger repetion axis. For instance, for keithley 1:

kth1.trigger_rep.set(5)

Autohios

It is possible to instruct bluesky to automatically set the High Order Suppressor (HIOS) motors to the desired values depending on the selected energy of the monochromator. There are three tables that can be used to select the HIOS motor positions. The tables are located in the folder ~/bluesky/beamlinetools/beamlinetools/hios

To activate autohios

# activate autohios
autohios(1) 

To deactivate autohios

autohios(0) 

Scan Examples

A few examples, see the Cookbook for a more comprehensive list of scans available.

Select detector to plot live

# use this command and follow the instructions
plotselect()

PTB scan

This scan let you choose how many times you want to mesure one single point, by setting the parameter repeat to the desired value. One can add as many motor as desired, with the following syntax:

ptb_scan motor1 start1 stop1 motor2 start2 stop2 n_points repeat=2

# example of a scan with one motor
ptb_scan motor -1 1 10 repeat=2

# example of a scan with two motors
ptb_scan motor -1 1 motor2 -2 2 10 repeat=2

Energy Scan

# scan motor start stop number_of_steps
scan pgm.en 400 600 100

Relative scan

# dscan motor start stop number_of_steps
dscan r.tx -1 1 20

Absolute scan

# scan motor start stop number_of_steps
scan r.tha 0 40 100

Scripting

Yuu can write scripts in the folder ~/bluesky/user_scripts/ptb, and then load them with:

load_user_scripts('ptb/ptb_example.py')