128 lines
4.0 KiB
Markdown
128 lines
4.0 KiB
Markdown
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# Magnetic Field Sweep and Spatial Mapping Automation
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**Author:** Serdar (adjusted by Lukas and Ryan)
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**Last Updated:** April 2025
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**Filename:** `Mag_Field_Sweep_2024_10_21.py`
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## Overview
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This script automates spectral acquisition in a magneto-optical experiment using:
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- **LightField** for spectrometer control (Princeton Instruments)
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- **AMC Positioner** for precise spatial scanning
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- **Attocube APS100** power supplies for magnetic field control
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It enables:
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- Magnetic field sweeps along selected axes
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- Spatial scans across X-Y positions
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- B-field vector rotations with spectral capture
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- Live spectrum acquisition and intensity mapping
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## Features
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- **2D Spatial Scan:** Raster-scan across a surface using AMC positioners, capturing spectra at each coordinate.
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- **Magnetic Field Sweep:** Vary B-fields in controlled steps along x/y/z, measure spectra at each step.
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- **Field Rotation:** Circular B-field rotation (in-plane) with angle-defined steps.
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- **Automated File Handling:** Acquires `.spe` files, extracts and saves intensity/wavelengths, deletes intermediates.
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- **Flexible Configuration:** Resolution, range, exposure, filters, filenames and scan directions are all customizable.
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## Prerequisites
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### Hardware
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- AMC100/AMC300 positioner
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- Attocube APS100 single/dual-channel magnet power supplies
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- Spectrometer compatible with Princeton Instruments LightField
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### Software & Libraries
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- **Python 3.8+**
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- Packages: `pyvisa`, `numpy`, `matplotlib`, `pandas`, `clr`, `spe2py`, `spe_loader`, `AMC` module
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- .NET integration via `pythonnet`
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- LightField SDK: Princeton Instruments (with DLLs loaded via `clr`)
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> Note: Ensure `LIGHTFIELD_ROOT` environment variable is set.
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## Setup
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1. **Install dependencies**
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```bash
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pip install pyvisa pandas numpy matplotlib pythonnet
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```
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2. **Ensure required DLLs** are present in:
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```
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C:\Program Files\Princeton Instruments\LightField\
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```
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3. **Set up device IPs**
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```python
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IP_AMC100 = "192.168.71.100" # or AMC300
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```
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4. **Edit scan parameters in main block:**
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```python
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range_x = 20000
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range_y = 20000
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resolution = 1000 # nanometers
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set_llim_bval = -0.3
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set_ulim_bval = 0.3
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set_res_bval = 0.003 # Tesla
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```
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## Main Functions
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### `move_scan_xy(range_x, range_y, resolution, Settings, baseFileName)`
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Performs a 2D XY raster scan of the probe. Acquires spectra and saves results.
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### `sweep_b_val(instr, min_bval, max_bval, res, axis, Settings, base_file_name)`
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Sweeps magnetic field (in T) along the specified axis, collecting spectra at each field.
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### `ramp_b_val(instr, bval, magnet_coil)`
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Smooth ramping of B-field to target value.
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### `b_field_rotation(instr1, instr2, Babs, startangle, endangle, step, Settings)`
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Rotates the in-plane magnetic field by vector combination of Bx and By components.
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## File Saving
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- `.txt`: Intensity data and wavelength arrays saved to timestamped folders
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- Folder names include experiment metadata
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- `.spe` files are deleted after processing to conserve space
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## Usage Example
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To sweep B-field along the **Y-axis**:
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```python
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sweep_b_val(
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instr=powerbox_singlesupply,
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min_bval=-0.3,
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max_bval=0.3,
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res=0.003,
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magnet_coil='y-axis',
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Settings='experiment_config',
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base_file_name='scan_name',
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zerowhenfin_bool=True,
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reversescan_bool=False,
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loopscan_bool=True
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)
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```
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## Notes
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- Always close power supply connections with `.close()`
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- Make sure `.spe` files are not locked by LightField before running
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- The AMC section is currently commented — uncomment if positioner control is needed
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- Ensure `experiment.Load(...)` points to the correct `.lfe` config
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## Troubleshooting
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- **DLL loading issues?** Confirm path via `sys.path.append(...)` and DLL names.
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- **Communication errors?** Check serial port resource names via `pyvisa.ResourceManager().list_resources()`
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- **No spectra saved?** Ensure LightField is licensed and experiment file is valid.
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## License
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Internal use only – please contact the authors before distribution or reuse.
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