UCLA-data

This code was written and tested in python 3.13.1. See requirements.txt for the packages and the versions used.

I highly recommend using a virtual environment for running this code. I like using virtualenvwrapper and pyenv, but venv is easier to setup and use.

Capabilities

HDF5 pre-processing

Code

The file h5_processing.py contains classes for preforming some initial processing on .h5 files collected from the laser control system. The PreProcessing classes automatically average data over positions and align LeCroy readouts in time. Pass processing='load_only to just load the raw data into the object processing=None to simply initialize it.

Sample use

Call PreProcessBdot either on an already loaded h5py instance or the path to an .h5 file. It will automatically collect information on LeCroy, MSO, motor positions, laser energy, and chamber pressure. It will then automatically average over positions and align LeCroy in time. Calling LeCroy, MSO, energy, or pressure gives the relevant data (the type hints should make clear what the output is). In addition, LeCroy_lineout gives the LeCroy data only for the y-axis lineout. unique_positions gives a series an array of tuples for each position containing the TCC coordinates and indexes of the shots which were taken at that point, and unique_pos_idx gives just the indexes of each unique position. Finally, lineout_positions gives the positions of the y-lineout and lineout_idx gives the index of the lineout positions in the averaged data.

The following snippet loads in LeCroy data that has been aligned and averaged:

file = h5py.File('path/to_file.h5)
loader = PreProcessBdot(file)
x, y, z, t = loader.LeCroy

To graph the average x probe reading at the closest point on the y-lineout (typically (0, 0.9, 0.85)), we can run the following code:

x_line, _, _, t_line = loader.LeCroy_lineout
x_pos0 = x_line[0]
t_pos0 = t_line[0]
plt.plot(t_pos0, x_pos0)
plt.show()

Finally, calling loader.summary() gives prints the following output with information on the h5 file. Passing the argument verbose=True prints substantial additional information on the positions

================================================================================
Summary statistics for to_file
>------------------------------------------------------------------------------<
Motor statistics:
  -> Total number of positions: 57
  -> Number of unique positions: 18
>------------------------------------------------------------------------------<
Other statistics:
  -> Laser energy: 9.368±0.079 J
  -> Chamber pressure: 96.839±1.203 mTorr
================================================================================

BDot probe calibration

Code

The file bdot_code.py contains two classes which contain all the useful functionality for an individual bdot probe including calibrating, reconstructing fields, generating reports, and loading saved calibration parameters.

The folder bdot_data/ contains the raw data used for calibration, the setup json files, and the already calibrated parameters.

Sample use

Probe calibration:

from bdot_code import ThreeAxisProbe

probe = ThreeAxisProbe(5, 'name')
probe.load_data('path_to_folder_for_probe_5_calibration_data')

probe.clip(50)

probe.calibrate(save=True, overwrite=True)
probe.gen_probe_report()

Explanation: When calling ThreeAxisProbe, you need to include the probe number, and, optionally, the name. The calibration data is expected to be nine files titles PjBi.TXT for i, j in (X, Y, Z) where the first 15 rows are header and, in order from left to right, columns for frequency (Hz), magnitude (unitless), and phase (deg). The first 50 data points are clipped because the phase signal tends to be extra noisy there. When calibrating, there setting overwrite=True allows any old data to be updated.

Field Reconstruction

from bdot_code import ThreeAxisProbe

probe = ThreeAxisProbe(2)
probe.load_params('bdot_data/params/probe_2.json)
field_vec = probe.reconstruct_field(probe_x, probe_y, probe_z, times, gain)

x_field, y_field, z_field = field_vec

To do

• improve documentation for bdot_code
• add auto-detection for voltage array sizes for field reconstruction in bdot_code
• improve documentation for h5_processing
• add TS specific aspects to h5_processing
• add general graphing capabilities (unsure what they would look like)
• add instructions for h5_processing to README

Contact

Nathaniel Bowers - bowena02@gettysburg.edu