GLaDOS-alpha 4.0

General Lookup of α-Decay for Optimised Search (GLαDOS)

General Lookup of α-Decay for Optimised Search (GLαDOS)

GLαDOS is a terminal-based alpha chain constructor, which can help in discerning possible summed energies due to fast decays. It can be used to search the nuclear chart for an energy-lifetime combination or to construct an alpha chain from a series of successive energies in coincidence, including possible sum peaks.

Setup

Pre-requisites

The GLαDOS package is a python package. It requires Python3 to be installed and pip to be up to date. It also requires the argparse and engineering_notation packages to be installed, but they will be automatically installed. If they are not, install them using pip install argparse and pip install engineering_notation, respectively.

Install

You can install the package directly through pip:

$ pip install GLaDOS-alpha

Or, alternatively, you can clone the package's git repository:

$ git clone https://github.com/Yottaphy/glados.git

and then enter the directory that was created and install

$ cd glados
$ pip install .

Usage

Once installed, GLαDOS can be used directly from the terminal. Some flags have to be included for the calculation to take place:

$ glados_alpha [-h] -i INPUTFILE [-z zmin zmax] [-n nmin nmax] [-e NUCLIDENAME] [-p PARENTENERGY] [-l lnTau] [-c CHILDENERGY] [-s SUMPEAK] [-t THIRDDECAY]

Flags in square brackets are optional. The rest are mandatory. -e triggers nuclide info, l triggers energy-lifetime search and -c triggers chain search. -c overrules -l.

Nuclide Info

To print the data for a single nuclide, the NUCLIDENAME option has to be passed, with the format XA, where X is the element symbol and A is the mass number. Valid examples are: U238, Pa227, He4. The following examples are invalid: 238U (wrong order), PA227 (bad capitalisation), he4 (bad capitalisation), U-238 (hyphen).

Energy-lifetime Search

PARENTENERGY is the energy of the alpha decay in keV, and lnTau is the natural log of the decay lifetime in seconds. A set of compatible candidates will be displayed in order of mass number. The range of searched energies is ±150 keV and the range of searched log lifetimes is ±1.

Chain Search

Chain search requires PARENTENERGY and CHILDENERGY. All chains within the range where two consecutive alpha decays (2 neutron, 2 proton steps) match the inputs within 150 keV will be displayed.

SUMPEAK is a number: 1 for summing in the first decay, 2 for summing in the second decay. Anything else will not assume summing. All possible chains, including summing in the indicated peak, will be displayed.

If the -t option is passed, no matter with what argument, the parent to the heaviest nucleus in the search will also be shown if it was found in the range.

Input

The input file is a comma separated value file that must contain the following columns in order: n, z, lifetime (s), alpha energy (keV), alpha energy error (keV), alpha intensity (%) and alpha intensity uncertainty (%). Isotopes that have several decay channels must have each channel in an individual row with all column values in it. Negative lifetimes are interpreted as stable/unknown.

The file alpha.dat provided in the Git repo can serve as an example or be used directly. It contains data taken from Nudat3, in the National Nuclear Data Center (Brookhaven National Laboratory, USA). The data was retrieved in May 2022.

Output

Output data are shown with the same units as they are input with. Lifetimes are shown with usual units (seconds, ms, us, hours, minutes, etc.).

The output shows a list of possible chains, each in their own table. They can be saved into an output file like:

$ glados_alpha [...] > outputname.txt

where [...] are the relevant flags and outputname.txt is the output file name, saved at the directory from which you launch GLαDOS.