MEASUREMENT DATA FILES ----------------------- This directory contains experimental measurement files generated using the ERDA-TOF (Elastic Recoil Detection Analysis - Time-of-Flight) technique at CMAM. These files store individual ion recoil events detected during irradiation with a heavy ion beam. For each detected event, two values are recorded: - The **kinetic energy** of the recoiling ion. - The **time of flight (TOF)** between two detection stations. The measurement files are structured in **list mode**: a long list of events, one per line, with each line containing two numerical values (energy and time). This format enables advanced post-processing, such as selecting subsets of events (e.g., comparing early vs. late experiment stages). Two formats may be present: - **Raw files**: Binary `.lst` files directly from the acquisition system. - **Processed files**: ASCII `.mpa` files, converted to readable text (e.g., by in-house software), containing: - Two columns: energy and TOF. - One row per detected event. These files can be easily imported into common data analysis tools and visualized as scatter plots of energy vs time. METADATA JSON FILES -------------------- Each measurement file is accompanied by a metadata JSON file named after the measurement (e.g., `Glass_02.json`). These files contain the contextual information necessary to interpret the associated experimental data. We recommend opening the JSON file in a code editor for better readability. Below is a complete list of the fields contained in these metadata files: 1. Name file: .json 2. Number of rows and columns: JSON object with ~30 parameters (1 object, not tabular). 3. Variables list: Below is the list of metadata fields and their descriptions. For numerical values, units are specified in a separate parameter with the same name followed by `_units`. Variable name: `name` Description: Internal identifier or label for the measurement file. Units: Text Variable name: `proposal` Description: Proposal code under which the measurement was performed. Units: Text Variable name: `beam_isotope` Description: Incident ion species used in the experiment. Includes name, symbol, mass number, and atomic number. Units: Structured object Variable name: `beam_charge_state` Description: Charge state of the incident ion beam. Units: Integer Variable name: `beam_energy` Description: Beam energy. Units: Specified in the `beam_energy_units` parameter Variable name: `sample_ID` Description: Identifier or label of the irradiated sample. Units: Text Variable name: `energy_detector` Description: Description of the energy detector used, including name, type, radiation type, and associated config file. Units: Structured object Variable name: `TOF_detector` Description: Description of the time-of-flight detector used, including name, type, radiation type, and associated config file. Units: Structured object Variable name: `terminal_voltage` Description: Terminal voltage of the accelerator. Units: Specified in the `terminal_voltage_units` parameter Variable name: `electromagnet_current` Description: Current applied to the analyzing electromagnet. Units: Specified in the `electromagnet_current_units` parameter Variable name: `beam_current` Description: Measured ion beam current at the sample position. Units: Specified in the `beam_current_units` parameter Variable name: `incident_angle` Description: Angle between the beam and the normal to the sample surface. Units: Specified in the `incident_angle_units` parameter Variable name: `exit_angle` Description: Angle between the recoil path and the normal to the sample surface. Units: Specified in the `exit_angle_units` parameter Variable name: `sample_TOF_detector_distance` Description: Distance between the sample and the TOF detector. Units: Specified in the `sample_TOF_detector_distance_units` parameter Variable name: `sample_energy_detector_distance` Description: Distance between the sample and the energy detector. Units: Specified in the `sample_energy_detector_distance_units` parameter Variable name: `length_of_flight` Description: Total flight path length between TOF stations. Units: Specified in the `length_of_flight_units` parameter Variable name: `TOF_station_BIAS_voltage` Description: Bias voltage applied to the TOF station. Units: Specified in the `TOF_station_BIAS_voltage_units` parameter Variable name: `TOF_TAC_range` Description: Time-to-Amplitude Converter (TAC) channel range. Units: Unitless Variable name: `TOF_TAC_multiplier` Description: Multiplication factor applied to TAC signal. Units: Unitless Variable name: `TOF_ADC_gain` Description: Gain applied to the TOF ADC signal. Units: Specified in the `TOF_ADC_gain` parameter (float) Variable name: `TOF_ADC_range` Description: ADC channel range for TOF signal. Units: Unitless Variable name: `energy_detector_BIAS_voltage` Description: Bias voltage applied to the energy detector. Units: Specified in the `energy_detector_BIAS_voltage_units` parameter Variable name: `energy_shaping_time` Description: Signal shaping time of the energy signal. Units: Specified in the `energy_shaping_time_units` parameter Variable name: `energy_amplifier_coarse_gain` Description: Coarse gain of the energy amplifier. Units: Unitless Variable name: `energy_amplifier_fine_gain` Description: Fine gain of the energy amplifier. Units: Unitless Variable name: `energy_ADC_gain` Description: Gain applied to the energy ADC signal. Units: Unitless Variable name: `energy_ADC_range` Description: ADC range for energy signal. Units: Unitless Variable name: `coincidence_window` Description: Time window for correlating signals from both detectors. Units: Specified in the `coincidence_window_units` parameter Variable name: `file_type` Description: Category identifier for the file type (used internally). Units: Text Variable name: `notes` Description: Free-text notes from the user or system. Units: Text ADDITIONAL FILES ---------------- In this directory, you will also find (if applicable) a subdirectory named "config_files/". This folder contains the detector configuration files referenced in the metadata fields "energy_detector" and "TOF_detector" under the "config_file" key. Each file provides technical specifications and calibration details relevant to the corresponding detector. These documents are essential for understanding the experimental setup and may be required for reanalysis or data comparison.