Lifetime Spectrum Generator

The Lifetime Spectrum Generator is a software tool designed to:

• Generate and save ideal lifetime spectra.
• Provide an advanced method for simulating complex spectra.

Installation

1. Download the file Lifetime Generator v1.0.exe.
2. Run the installer to install the software.
3. After installation, open the software.

Upon opening the software, the following panel will appear:

Usage

In the main panel, you can choose between:

• Ideal Spectra Generator: A basic tool for generating ideal spectra.
• PMT Pulse Stream Generator: A more complex simulation tool.

Click on the respective button to open the corresponding software.

Ideal Spectra Generator

The Ideal Spectra Generator allows you to generate ideal spectra by entering the required parameters. It supports up to 5 components with different intensities (as shown in Bild2.png).

Parameters:

• Number of Components: Select the number of components in the spectrum.
• Spectrum Range (ns): Set the x-axis range in nanoseconds.
• Binning (ps): Choose the binning for the histogram in picoseconds.
• Number of Counts: Set the total count in the resulting spectrum.
• IRF (Instrument Response Function): You can define up to two Gaussian functions with arbitrary widths. One of the functions can be time-shifted.
• BG (Background): Set the background count percentage. 1 corresponds to 100%.
• Continuous Lifetime: By enabling this checkbox, continuous lifetimes are used instead of discrete ones. The selected lifetimes represent the mean of the lifetime distributions, and their width is determined by the sigma value (in ns).

Generating and Saving Spectra

After setting your desired parameters, click "Start" to generate the spectrum. You can then save the generated spectrum as a .txt file by clicking the "Save" button.

PMT Pulse-Stream Generator

The PMT Pulse-Stream Generator does not directly simulate a lifetime spectrum. Instead, it simulates PMT pulse pairs that contain the information necessary to determine the lifetime.

As shown in Figure 3, the different components of the spectrum can be identified:

1. True Coincidence Events
   These events contain the actual lifetime information and make up the majority of a typical spectrum (around 80%). They represent real coincidences between detected events and are the main focus when analyzing the spectrum.

2. Background Events
   Background events are uncorrelated events that occur due to the intensity of the source. These events are indistinguishable from true coincidence events and form the linear background of the spectrum.

3. Pile Ups
   Pile ups occur when an additional pulse, caused by another decay, overlaps with a coincidence event. This leads to distorted time signals. The amount of pile ups is primarily influenced by the strength of the radioactive source being used.

4. 1275 keV Backscattering
   These events are caused by 1275 keV gamma quanta that undergo backscattering, interacting with both detectors. This can result in a false coincidence event that does not carry lifetime information.

5. Bad Coincidence Events
   Bad coincidences occur when both collinear 511 keV gamma quanta, as well as the 1275 keV gamma, are detected. This leads to an amplitude shift of the 1275 keV gamma quantum in the PMT, resulting in a distorted time determination.

## Configuration Settings for PMT Pulse-Stream Generator

1275 keV Backscattering Configuration

In this section, you can define the pulse height distribution of backscattered 1275 keV events within the 511 keV energy range. This distribution is defined using an exponential function. The parameter Lambda determines the shape of the exponential distribution, while two additional parameters define the lower and upper limits of the range.

Digitizer Setup

Here, you can configure the basic properties of the digitizer to be simulated.

Detector Setup

In this section, you can define parameters related to the characteristics of the PMT (Photomultiplier Tube) and the scintillator being used. This setup defines the shape and noise behavior of the PMT output pulses.

Positron Lifetime Configuration

As with the ideal spectrum generator, this section allows you to define the positron lifetime.

Number of Pulse Pairs

This setting defines the number of pulse pairs to be generated. It is important to note that this does not correspond directly to the counts in the spectrum, as pulses are generated across the entire PHS (Pulse Height Spectrum) range.

Important Note

Be sure to save the data on an external hard drive, as the generated files can quickly reach sizes in the hundreds of gigabytes.

License

[Add your preferred license here]