Quickstart

This page takes you from a fresh install to a first fitted result in a few minutes — and you need no data of your own, because Asymmetry can generate a realistic demo run for you. The objects each step refers to are collected in Key concepts, and complete real-world analyses follow in Analysis workflows.

Install and launch

Install Asymmetry (see Installation) and start the graphical interface from a terminal:

asymmetry-gui

The main window opens with an empty Data Browser on the left and a plot in the centre.

Make a demo dataset

With your own data you would load a file from File → Open… and then set the detector grouping and calibrate \(\alpha\) (see Grouping and calibration walkthrough). With nothing to hand, generate a ready-made run instead:

  1. Open File → Simulate Preset.

  2. Choose Ag — ZF Gaussian Kubo–Toyabe.

A synthetic silver run appears in the Data Browser, badged SIM and tinted to mark it as simulated, and the central plot shows its asymmetry — already grouped and calibrated, because the preset carries a complete reduction. The preset is a genuine Poisson-sampled dataset built from a known model, so it behaves exactly as beamline data would.

Read the asymmetry

The curve is the zero-field Kubo–Toyabe relaxation of muons in silver: a characteristic dip and partial recovery produced by the static distribution of nuclear dipolar fields at the muon site, with a width set by the spread of those fields. This time-domain signal is what every fit works on; for the physics behind it see Muon-spin spectroscopy: a primer and Kubo–Toyabe.

Fit it

Fit the relaxation and recover its parameters:

  1. In the fit panel’s single-fit tab, open the Fit Wizard.

  2. Click Start Analysis. The wizard fingerprints the spectrum, fits a portfolio of candidate models, and ranks them by an information criterion.

  3. It recommends StaticGKT_ZF + Constant — the static Gaussian Kubo–Toyabe with a flat baseline. Click Apply Recommended Fit to write the result back into the single-fit tab.

The fitted field width comes out at \(\Delta \approx 0.39\) μs⁻¹ — the value the preset was generated from, recovered within the counting errors. That is a complete analysis: data in, model fitted, parameter out.

The main window after the first fit, with the fitted Gaussian Kubo–Toyabe curve overlaid on the silver asymmetry data and the converged parameters shown in the fit panel.

The main window right after the walkthrough’s first fit converges. The red fit curve traces the StaticGKT_ZF + Constant model over the silver asymmetry, and the fit panel reports Fit converged with Δ = 0.39 μs⁻¹ (row Δ (μs⁻¹) ) and a reduced chi-square near 1.

Where to go next